Psychosocial factors and duration of breastfeeding among women in

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					Psychosocial factors and duration of breastfeeding among women in Denmark

                                                           Annotated Bibliography
                                                                          CIS 495
                                                                     Lucy Marcil
Table of Contents

Data set                 3

General breastfeeding    3

Postpartum depression    6

Psychosocial factors     9

Biological factors       14

Alcohol                  16

Smoking                  19

Medications              20

Breastfeeding policies   23

Data set

Olsen, J., Melbye, M., Olsen, S. F., Sorensen, T. I., Aaby, P., Andersen, A. M., et al. (2001). The
       Danish National Birth Cohort--its background, structure and aim. Scand J Public Health,
       29(4), 300-307.

This article describes the conception of the Danish National Birth Cohort (DNBC), a data set
designed to allow long-term study of pregnancy and early life morbidity and mortality. This area
of study is especially important because of a high correlation between infant health and later life
health. The ethics committee granted permission to follow the cohort for 20 years. The authors
purposefully designed the cohort to include a large number of dyads (100,000) to allow study of
rare conditions. They recruited subjects through general practitioners (GPs). Some regional
unions initially recommended that GPs not participate in the study, which led to somewhat
biased subject selection. Data collection included four telephone interviews during and after
pregnancy, a food frequency questionnaire, blood sampling, and linkage to national disease
registers. One shortcoming of the study is that it required women speak Danish well enough to
participate in a telephone interview. Thus, most of the immigrant population was excluded. Ten
percent of pregnancies occur in immigrants.

General breastfeeding

Ball, T. M., & Wright, A. L. (1999). Health care costs of formula-feeding in the first year of life.
        Pediatrics, 103(4 Pt 2), 870-876.

These authors assessed the relative risk of lower respiratory tract illness, otitis media, and
gastrointestinal illness in respect to breastfeeding status in the first year of life. Subjects were
1588 American and Scottish infants, who were characterized as never, partially, or exclusively
breastfed. They found that compared to exclusively breastfed infants, never breastfed ones had
excessive office visits, hospitalization and prescriptions. These difference translate into an extra
$331-$475/infant during the first year. This study does not include a long-term analysis of costs,
nor does it try to quantify indirect costs and benefits. However, it provides moderately strong
evidence in favor of policies promoting breastfeeding.

Benis, M. M. (2002). Are pacifiers associated with early weaning from breastfeeding? Adv
       Neonatal Care, 2(5), 259-266.

This randomized study assessed the efficacy of a counseling intervention advocating decreased
pacifier use. Some theorize that pacifier use may lead to incorrect suckling technique during
breastfeeding. Out of 281 women, 140 were advised to avoid pacifiers and given alternative
techniques for dealing with fussy infants (experimental group). Both groups were counseling on
the benefits of breastfeeding. Researchers did find that women in the experimental group were
less likely to give pacifiers and also less likely to wean by 3 months. However, some causal
ambiguity does exist. A third intervening variable, such as breastfeeding problems or lack of
breastfeeding motivation, may explain both increased pacifier use and early weaning.

Birth, Initiation of breastfeeding, and the First Seven Days after Birth. In Facts for Feeding.
        (2003). Academy for Educational Development.

This document provides an easily understandable guide for health care providers on promoting
exclusive breastfeeding during labor and delivery, the first few hours after birth, the first few
days after birth, and the rest of the first week after birth. This information is critical since early
successful breastfeeding is predictive of long-term success. The document includes strategies for
both proactive care and interventions when problems arise. This type of paper is a useful
example of effective dissemination of information to health care professionals. Information
dissemination is necessary for the successful implementation of policies.

Grummer-Strawn, L. M., & Mei, Z. (2004). Does breastfeeding protect against pediatric
     overweight? Analysis of longitudinal data from the Centers for Disease Control and
     Prevention Pediatric Nutrition Surveillance System. Pediatrics, 113(2), e81-86.

This study assesses the relationship between duration of breastfeeding and body mass index
(BMI) in a cohort of low-income 4 year olds. Dietary and other lifestyle factors probably differ
between low and higher income children, so these results may not be applicable to children in
higher socioeconomic groups (as in my study). The authors found that longer durations of
breastfeeding were related to lower risk of over- and underweight among Caucasians. This
effect was only present for breastfeeding durations of 3 months or longer. Behavioral
differences may explain why the relationship was insignificant for Hispanic and Black children.

Philipp, B. L., Merewood, A., & O'Brien, S. (2001). Physicians and breastfeeding promotion in
       the United States: a call for action. Pediatrics, 107(3), 584-587.

This article reviews the current breastfeeding situation in the US and provides suggestions for
improvement. The authors note that although breastfeeding rates in the US are low in general,
they are much lower among WIC recipients. This difference is at least partially due to formula
coupons. Many pediatricians, experts with potential to influence maternal behavior, also lack
adequate breastfeeding knowledge. This article further points out that the US lags behind other
countries in respect to implementing the Baby Friendly Hospital Initiative (WHO sponsored).
Only 25 US hospitals are certified Baby Friendly, in comparison to > 16,000 worldwide. The
US also has failed to enforce the International Code of Marketing of Breast Milk Substitutes.
Finally, the authors provide some suggestions, which mainly focus on the agency of pediatricians
to better educate themselves and their patients about breastfeeding and to become politically
active on the issue.

Li, R., Darling, N., Maurice, E., Barker, L., & Grummer-Strawn, L. M. (2005). Breastfeeding
        rates in the United States by characteristics of the child, mother, or family: the 2002
        National Immunization Survey. Pediatrics, 115(1), e31-37.

This article reviews breastfeeding rates, subdivided by demographics, in the US. The data
originates from the National Immunization Survey (NIS), which included questions on
breastfeeding for the first time in 2001. Although breastfeeding initiation occurred among
71.4% of infants (a relatively high rate close to national goals), exclusive breastfeeding rates at 3

and 6 months were 42.5% and 13.3%, respectively. These rates are significantly below stated
goals. The authors found that rates were lowest among blacks, those in day care or on WIC,
lower socioeconomic groups, and in some geographic regions. Overall, this article provides
good evidence for the need for breastfeeding promotion initiatives, especially among risk-

Sikorski, J., Renfrew, M. J., Pindoria, S., & Wade, A. (2003). Support for breastfeeding mothers:
       a systematic review. Paediatr Perinat Epidemiol, 17(4), 407-417.

This article provides a comprehensive review of the literature on the effects of lay and
professional breastfeeding support on duration of breastfeeding. The authors concluded that
support had a larger positive effect on duration of exclusive breastfeeding than on duration of
partial breastfeeding. However, when support was divided into professional and lay,
professional support only influenced duration of partial breastfeeding while lay support only
influenced duration of exclusive breastfeeding. These results indicate that further studies are still
needed to fully understand the precise benefits of added support. Overall, though, support seems
to be beneficial and should be offered more widely.

The National Breastfeeding Committee Denmark. (2004). A Snapshot 2002. Unpublished data
compiled by the National Breastfeeding Committee in Copenhagen, Denmark.

This document provides graphical data on women’s interactions with health care professionals in
respect to breastfeeding. 458 Danish women took part in the survey.
The National Breastfeeding Committee Denmark. (n.d.). [Summary data]. An unpublished
report of the breastfeeding situation in Denmark compiled by the National Breastfeeding
Committee in Copenhagen, Denmark.

This document provides pertinent information on breastfeeding attitudes and rates in Denmark.
It also assesses the Baby Friendly Hospital Initiative and other on going policy efforts to improve
breastfeeding rates in Denmark. Thus, this paper provides crucial background information for
my analyses.

WHO. (1998). Evidence for the ten steps to successful breastfeeding, Geneva, Switzerland (No.

This document presents ten steps supporting breastfeeding that hospitals and other health
facilities providing maternity care should follow. These steps are the key elements of the Baby
Friendly Hospital Initiative. If hospitals adequately follow these steps, then the WHO will
certify them as Baby Friendly. This report carefully presents each of the ten steps, reviews
literature supporting the importance of each step, and then draws conclusions offering practical
advice on achieving the particular step. These ten steps are an excellent example of practical and
realistic policies that can be used to promote breastfeeding. This policy especially focuses on
breastfeeding initiation while in the hospital, with the expectation that higher rates of successful
initiation will lead to longer duration.

Yngve, A., & Sjostrom, M. (2001). Breastfeeding in countries of the European Union and EFTA:
      current and proposed recommendations, rationale, prevalence, duration and trends. Public
      Health Nutr, 4(2B), 631-645.

This article is a useful EU specific source that delineates trends and differences in breastfeeding
among European countries. Notably, the authors point out that most studies have focused on any
breastfeeding, while evidence indicates that exclusive breastfeeding is the most beneficial type.
Generally, they emphasize the need for more comprehensive and comparable studies on a wide
array of factors influencing breastfeeding. They also call for a European breastfeeding
conference to initiate action. The article does include some Denmark specific information and

Postpartum depression

Berle, J. O., Aarre, T. F., Mykletun, A., Dahl, A. A., & Holsten, F. (2003). Screening for
        postnatal depression. Validation of the Norwegian version of the Edinburgh Postnatal
        Depression Scale, and assessment of risk factors for postnatal depression. J Affect Disord,
        76(1-3), 151-156.

The authors of this study assessed the usefulness of the Edinburgh Postnatal Depression Scale
(EPDS) in Norway in a sample of 411 women. The information contained in this paper was very
useful to me when I was calculating an appropriate cut point for my depressive symptoms scale.
Here, the authors found the scale was valid (through both specificity and sensitivity), which is
also important information for my study. Since my scale was very close to the EPDS, if the
EPDS was not a valid measure in Scandinavian populations, my scale might not be either. Ten
percent of this study population qualified as having major and minor depression, which
corroborates other findings that the prevalence of postpartum depression in Western populations
is 10-15%.

Carter, F. A., Carter, J. D., Luty, S. E., Wilson, D. A., Frampton, C. M., & Joyce, P. R. (2005).
        Screening and treatment for depression during pregnancy: a cautionary note. Aust N Z J
        Psychiatry, 39(4), 255-261.

This New Zealand study used the EPDS to screen pregnant women for depression. Researchers
used a cut point very similar to that used in the Berle et al study, which further validates the
appropriateness of the general cut off (while reminding that slight variations do occur between
countries). The authors found that most women were willing to be screened with the EPDS, but
most were unwilling to participate in further assessments or treatments. These findings
emphasize the difficulties associated with identifying and treating women with postpartum
depression. Stigma may be a major obstacle here. Thus, this article indicates that personalized
screening through a trusted health professional may be necessary to adequately intervene in
postpartum depression. This finding should help guide policy.

Eberhard-Gran, M., Eskild, A., Tambs, K., Schei, B., & Opjordsmoen, S. (2001). The Edinburgh
      Postnatal Depression Scale: validation in a Norwegian community sample. Nord J
      Psychiatry, 55(2), 113-117.

Like the Berle et al study, this one also sought to validate the EPDS in Norway. The authors
concluded that a cut point of ≥ 10 was appropriate. This cut off is one point lower than in the
Berle et al study. However, researchers here were utilizing the scale in a non-clinical setting, for
which lower cut points are usually appropriate. The authors also point out that EPDS is superior
to regular depression scales when screening for postpartum depression because new mothers
often experience fatigue, lack of sleep, and changes in appetite. All of these symptoms are
characterized as signs of regular depression, but can lead to misdiagnosis in new mothers.

Edhborg, M., Friberg, M., Lundh, W., & Widstrom, A. M. (2005). "Struggling with life":
      narratives from women with signs of postpartum depression. Scand J Public Health,
      33(4), 261-267.

This Swedish study provides a qualitative analysis of the problems women with postpartum
depression encounter. Since most of my references utilize quantitative statistical analyses, this
study is very useful to me. It provides insight into the thoughts and feelings of new mothers.
This research is doubly useful since it occurred in a Scandinavian population. The authors
interviewed 22 women with signs of postpartum depression, which was identified using the
EPDS. Many women reported breastfeeding problems, which they indicated made them feel like
failures. Breastfeeding is very much a norm in Scandinavia so women there likely experience
much greater social pressure to breastfeed than do women in the US. Also, this paper provides
evidence that stigma does exist in Scandinavia in respect to postpartum depression.

Falceto, O. G., Giugliani, E. R., & Fernandes, C. L. (2004). Influence of parental mental health
       on early termination of breast-feeding: a case-control study. J Am Board Fam Pract,
       17(3), 173-183.

This study occurred in Brazil, which weakens its applicability to my study in Denmark.
However, the authors did find that mental health disorders in the first month postpartum were
correlated with early termination of breastfeeding. Depression was only one of the disorders
included in the variable “mental health disorder,” and the researchers screen for depression using
the Self-Reporting Questionnaire, not EPDS.

Georgiopoulos, A. M., Bryan, T. L., Wollan, P., & Yawn, B. P. (2001). Routine screening for
      postpartum depression. J Fam Pract, 50(2), 117-122.

This study evaluated the long-term usefulness of the EPDS as a screening tool in a US
community. Other studies cited have not looked at the scale’s long-term usefulness, so this study
adds important information. The authors found that postpartum depression was diagnosed at a
rate of 3.7% before the screening tool intervention and 10.7% afterwards. Given the evidence on
the prevalence of postpartum depression, the latter percentage is probably much closer to the true
population rate. Of women who qualified as having depressive symptoms based on their
responses to the EPDS, 35% were clinically diagnosed with depression. Only 5% of those who

did not qualify through EPDS were diagnosed with depression. Thus, high EPDS scores
predicted depression well. Overall, EPDS seems to be a useful tool in this community, which
implies that it should be considered as an effective policy tool in other communities as well.

Henderson, J. J., Evans, S. F., Straton, J. A., Priest, S. R., & Hagan, R. (2003). Impact of
      postnatal depression on breastfeeding duration. Birth, 30(3), 175-180.

This study followed 1745 women for 12 months postpartum. The focus of this study is the same
as my main focus so their findings are extremely pertinent. The authors did differentiate
between partial and exclusive breastfeeding. They found that the onset of postpartum depression
occurred before two months postpartum for 63% of the women who experienced it. This finding
implies that my sample may have problems with recall bias since my subjects were asked at six
months postpartum if they had experienced symptoms anytime during the past six months. The
authors also found that postpartum depression and early breastfeeding cessation were
significantly correlated.

Mezzacappa, E. S. (2004). Breastfeeding and maternal stress response and health. Nutr Rev, 62(7
      Pt 1), 261-268.

This review article focuses on the physiological effects of breastfeeding on the mother.
Evidence suggests that breastfeeding may have a positive effect on the neuroendocrine system
and actually reduce the experience of depressive symptoms. Thus, the relationship between
breastfeeding and postpartum depression may be circular. This finding is an important
consideration when interpreting the results of my associations.

Nishizono-Maher, A., Kishimoto, J., Yoshida, H., Urayama, K., Miyato, M., Otsuka, Y., et al.
       (2004). The role of self-report questionnaire in the screening of postnatal depression- a
       community sample survey in central Tokyo. Soc Psychiatry Psychiatr Epidemiol, 39(3),

The authors attempt to establish the usefulness of the EPDS as a screening tool in Japan.
Because of significant cultural differences, their findings may not be directly applicable for
Denmark. However, they did find that 13.9% of new mothers were high scorers on the scale,
which compares to the rates seen in Scandinavian studies. This article especially focuses on the
issue of stigma, which creates a need for a reliable, standard screening device. Otherwise,
postpartum depression will continue to be under diagnosed, which will propagate stigma in a
cyclical manner.

Robertson, E., Grace, S., Wallington, T., & Stewart, D. E. (2004). Antenatal risk factors for
       postpartum depression: a synthesis of recent literature. Gen Hosp Psychiatry, 26(4), 289-

This article does not directly address breastfeeding but instead reviews the literature on factors
leading to postpartum depression. This subject is important since decreasing the prevalence of
postpartum depression in the first place would decrease its opportunity to negatively affect
duration of breastfeeding. In a meta-analysis of past data, the authors found that past

experiences with depression, anxiety or stress during pregnancy, and low levels of social support
all predicted postpartum depression. The authors also note that more research is needed on the
appropriateness of different screening tools in different populations. Clearly, this topic is
important since postpartum depression cannot be treated if it is not diagnosed. Health
professionals must make sure that they are using a tool that is useful within their cultural context.

Seimyr, L., Edhborg, M., Lundh, W., & Sjogren, B. (2004). In the shadow of maternal depressed
      mood: experiences of parenthood during the first year after childbirth. J Psychosom
      Obstet Gynaecol, 25(1), 23-34.

This Swedish study utilized the EPDS to assess postpartum depression in first year mothers. The
authors used a cut point of 10, which is identical to that used in the Norwegian Eberhard-Gran et
al study and one off from the Norwegian Berle et al study. Thus, the EPDS seems to be a rather
consistent tool within Scandinavian populations. This information allows me to more
confidently extend it to a Danish population. The authors did find that maternal depressive
symptoms decreased duration of breastfeeding, which corroborates my findings.

Taj, R., & Sikander, K. S. (2003). Effects of maternal depression on breast-feeding. J Pak Med
        Assoc, 53(1), 8-11.
This study of a Pakistani population asserts that breastfeeding may have positive effects on
mental health. The applicability of the findings to a Danish population is questionable because
of significant cultural differences. The authors did find that women with depressive symptoms
stopped breastfeeding sooner. However, they note that the symptoms proceeded cessation of
breastfeeding, which indicates that depression probably led to ceasing breastfeeding, not vice

Terp, I. M., Engholm, G., Moller, H., & Mortensen, P. B. (1999). A follow-up study of
        postpartum psychoses: prognosis and risk factors for readmission. Acta Psychiatr Scand,
        100(1), 40-46.

This study does not directly examine breastfeeding but rather examines the negative effects of
and risk factors for postpartum psychoses, a more serious form of postpartum depression. The
information in this paper is useful because understanding risk factors for mental health disorders
can help decrease their prevalence, which could help increase the prevalence of breastfeeding in
the maternal population. Also, the subjects in this study are Danish, which makes the results
very applicable to my study population, especially in respect to important cultural factors
affecting mental health.

Psychosocial factors

Cernadas, J. M., Noceda, G., Barrera, L., Martinez, A. M., & Garsd, A. (2003). Maternal and
      perinatal factors influencing the duration of exclusive breastfeeding during the first 6
      months of life. J Hum Lact, 19(2), 136-144.

The authors conducted this mid-sized study (537 women) in Argentina. The non-Western
location of this study limits its applicability to my study in Denmark. This study also focused on
only the first 6 months postpartum whereas the DNBC collected data through 18 months.
However, exclusive breastfeeding, their outcome, only occurs for a maximum of 6 months.
Thus, the duration of their study was adequate for their purpose. The authors found that positive
maternal attitudes towards breastfeeding, adequate family support, good mother-infant bonding,
appropriate suckling technique and the absence of nipple problems all led to longer duration of
exclusive breastfeeding. They did control for biological and demographic variables, which
strengths the validity of these findings.

DiGirolamo, A., Thompson, N., Martorell, R., Fein, S., & Grummer-Strawn, L. (2005). Intention
       or experience? Predictors of continued breastfeeding. Health Educ Behav, 32(2), 208-

The authors focused on the relationship between prenatal intention to breastfeed and actual
duration of breastfeeding among 1665 US women. Although it seems intuitive that women who
intend to breastfeed would be more likely to actually succeed, it is still important to scientifically
establish that a relationship does exist. The authors did find the expected relationship but also
found that initial breastfeeding experiences modify the relationship. This factor is just one of
many that contributes to duration of breastfeeding.

Kirkland, V. L., & Fein, S. B. (2003). Characterizing reasons for breastfeeding cessation
       throughout the first year postpartum using the construct of thriving. J Hum Lact, 19(3),

The authors examined 758 mothers from the US Food and Drug Administration’s Infant Feeding
Practices Study (IFPS). Their chosen focus is based on Orem’s theory that nutritional,
psychological, and lifestyle demands can “overwhelm a mother’s physical and/or mental
capacity to care for herself and her dependents” (p. 279). They found that most women ceased
breastfeeding because of lifestyle factors (wanting to leave infant or wanting to share feeding
duties) and personal perceptions (milk was insufficient nutritionally, infant was too old for
breastfeeding). This study provided interesting information on the mother’s direct perception of
her reasons for breastfeeding cessation. These perceptions may not always include all factors
that led to cessation. However, the authors failed to differentiate between exclusive (only breast
milk plus water) and partial (breast milk plus any other substances) breastfeeding as outcomes.

Kloeblen-Tarver, A. S., Thompson, N. J., & Miner, K. R. (2002). Intent to breast-feed: the
       impact of attitudes, norms, parity, and experience. Am J Health Behav, 26(3), 182-187.

This study examined a low-income cohort of 963 women. The focus on low-income women
makes the findings less directly applicable to the women in the Danish National Birth Cohort
(DNBC), most of whom are of middle to upper SES. Researchers found that attitudes were most
predictive of breastfeeding intent. Previous experience was also important for multiparous
women (those with previous children). This study focuses on intention to breastfeed rather than
duration (my focus). Theoretically, different variables contribute to intent and duration, but
some overlapping causative factors probably exist.

Kronborg, H., & Vaeth, M. (2004). The influence of psychosocial factors on the duration of
      breastfeeding. Scand J Public Health, 32(3), 210-216.

The authors studied a cohort of 471 Danish women for four months. Because the subjects are
Danish, this study is especially relevant to my research. The researchers used survival analysis
to assess the significance of their variables because most (59%) of women were still exclusively
breastfeeding at the conclusion of the study. They did not evaluate partial breastfeeding as an
outcome. Analyses showed that increased maternal self-efficacy, confidence, knowledge, intent,
and prior experience in respect to breastfeeding all lead to increased duration of breastfeeding.
Knowledge was only significant among primiparous (first time) mothers. Increased maternal
education also had a positive effect on breastfeeding duration. Importantly, over half (51%) of
women who ceased breastfeeding did so during the first five weeks postpartum. Researchers and
clinicians should be especially cognizant of this increased risk in the early postpartum period.

Lande, B., Andersen, L. F., Baerug, A., Trygg, K. U., Lund-Larsen, K., Veierod, M. B., et al.
       (2003). Infant feeding practices and associated factors in the first six months of life: the
       Norwegian infant nutrition survey. Acta Paediatr, 92(2), 152-161.

This study assessed a range of psychosocial factors associated with duration of breastfeeding in a
cohort of 2383 Norwegian infants. These results are directly pertinent to my study since the
authors analyze many of the same variables and use a Scandinavian population. The authors do
differentiate between partial and exclusive breastfeeding. They found breastfeeding duration
was positively associated with maternal education, maternal age, infant gender, and martial

Rempel, L. A. (2004). Factors influencing the breastfeeding decisions of long-term breastfeeders.
      J Hum Lact, 20(3), 306-318.

This small study used the theory of planned behavior to evaluate planned and actual
breastfeeding durations among 80 women in the US. Based on this theory, Rempel assessed the
effects of maternal attitudes, social approval, and perceived control on breastfeeding behavior.
The author did not differentiate between partial and exclusive breastfeeding. Overall, she found
that perceived approval of breastfeeding decreased as the infant aged and that this approval had a
strong effect on intended duration at 9 months postpartum. A mother’s perceived control over
breastfeeding affected intended duration at both the prenatal and 9-month assessments. The two
reasons women most cited for weaning between 9 and 12 months were perceived readiness of the
infant to wean and the belief that the infant had received enough or all breastfeeding benefits by
this time point. Interesting, women’s reasons for weaning were most related to perceived control
rather than perceived social approval.

Scott, J. A., & Binns, C. W. (1999). Factors associated with the initiation and duration of
        breastfeeding: a review of the literature. Breastfeed Rev, 7(1), 5-16.

This literature review provides a comprehensive summary and comparison of recent findings on
factors affecting breastfeeding decisions. The authors limit their review to findings on Western

women and to studies that utilized multivariate analyses, a more informative method than
univariate analyses. Overall, they conclude that a wide range of variables contributes to
breastfeeding decisions, but many findings in the literature are inconsistent. Demographic
factors seem to more consistently affect these decisions than do biomedical ones. Scott and
Binns did find a constant inverse relationship between maternal smoking and breastfeeding
duration. Studies on psychosocial variables consistently indicate that fathers have an important
influence on maternal decisions in relation to breastfeeding and that intended duration strongly
predicts actual duration. This later finding is rather intuitive. This article serves as a good
reminder that a complex interaction of multiple variables influences breastfeeding decisions.

Scott, J. A., Landers, M. C., Hughes, R. M., & Binns, C. W. (2001). Psychosocial factors
        associated with the abandonment of breastfeeding prior to hospital discharge. J Hum
        Lact, 17(1), 24-30.

This Australian study of 1059 women assessed cessation of breastfeeding within the first week
postpartum. Their measurement of breastfeeding included both exclusive and partial.
Psychosocial variables affecting the decision to cease breastfeeding may be very different in the
first week and at six months, which makes their finding less relevant for me. The researchers
found that low commitment levels (deciding to breastfeed after becoming pregnant), lack of
social support (by the father), and lack of prior exposure to breastfeeding (through the mother’s
mother) were all risk factors for abandoning breastfeeding while still in the hospital. Hospital
discharge times varied, which may have confounded these results. However, researchers did
follow up with the women for up to six months. The authors found that most women who ceased
breastfeeding did so in the first six weeks postpartum, which is similar to what the Kronborg
study (see above) found.

Shaker, I., Scott, J. A., & Reid, M. (2004). Infant feeding attitudes of expectant parents:
       breastfeeding and formula feeding. J Adv Nurs, 45(3), 260-268.

This Scottish study compared prenatal breastfeeding attitudes of both mother and father to infant
feeding method at discharge from the hospital. The inclusion of the father in data collection is
very important since previous research has indicated that his opinions and behaviors strongly
influence the mother’s breastfeeding decisions (Scott & Binns, 1999). The 108 couples consist
of a convenience sample; this method of data collection may have introduced some bias into the
results. The authors did not differentiate between exclusive and partial breastfeeding. Parents
with breastfed infants at discharge had more positive attitudes toward and greater knowledge of
the benefits of breastfeeding. Regardless of feeding method, fathers were more disapproving
than mothers of breastfeeding in public. Mothers of formula fed infants were more disapproving
of drinking alcohol while breastfeeding. This last finding is important for my study since I found
that women drinking alcohol actually breastfed longer.

Sullivan, M. L., Leathers, S. J., & Kelley, M. A. (2004). Family characteristics associated with
       duration of breastfeeding during early infancy among primiparas. J Hum Lact, 20(2),

This study investigated the effect of gender roles on breastfeeding duration (either exclusive or
partial). Unlike the Danish National Birth Cohort subjects, these 115 American women were
ethnically diverse. Using survival analyses, the authors found that women with higher levels of
relationship distress ceased breastfeeding sooner. Surprisingly, they found that women with
higher levels of responsibility for infant care and household tasks continued breastfeeding
longer. The authors postulate that this correlation may exist because some tasks are more
convenient for breastfeeding women to complete, which naturally leads to a higher level of
responsibility for these tasks. This study is one of few to provide evidence that comprehensive
aspects of the couple’s relationship (not just paternal support of breastfeeding) influence duration
of breastfeeding.

Taveras, E. M., Capra, A. M., Braveman, P. A., Jensvold, N. G., Escobar, G. J., & Lieu, T. A.
      (2003). Clinician support and psychosocial risk factors associated with breastfeeding
      discontinuation. Pediatrics, 112(1 Pt 1), 108-115.

This US study followed 1163 mother-infant dyads for 12 weeks. Eighty-seven percent of
women in this cohort initiated breastfeeding, which is much higher than the average rate in the
US (64%). This dichotomy indicates that the study subjects were of higher socioeconomic status
(SES) than the average American women. Demographic statistics support this inference.
Because these women are not representative of the typical American, they are more similar to
Danish women and particularly the women in the Danish National Birth Cohort. Researchers
found that lower SES was a risk factor for breastfeeding cessation. They also found that
maternal depressive symptoms were correlated with increased breastfeeding discontinuation.
This finding is very pertinent to my study. Furthermore, the authors found that clinician support
is very important to breastfeeding success. Returning to work or school at 12 weeks was one of
the strongest indicators of discontinuation, which indicates the importance of maternity leave.
These findings identify several areas for policy changes.

Taveras, E. M., Li, R., Grummer-Strawn, L., Richardson, M., Marshall, R., Rego, V. H., et al.
       (2004). Opinions and practices of clinicians associated with continuation of exclusive
       breastfeeding. Pediatrics, 113(4), e283-290.

This American study of 288 mothers provides strong evidence for the importance of clinicians in
respect to breastfeeding decisions. The authors investigate only exclusive breastfeeding. Thus,
the applicability of these findings to partial breastfeeding is uncertain. Also, the researchers
selected women who were breastfeeding at four weeks to participate in the study. Again, this
limitation makes it difficult to conclude what the clinician’s role may be in the first month
postpartum. Overall, they found that mothers with biomedical problems and those whose
clinicians recommended formula use were more likely to cease breastfeeding. Clinicians with
confidence in the importance of their advice had a greater positive effect on duration of
breastfeeding among their patients. Clinicians also reported having little time to preemptively
discuss breastfeeding problems. These findings indicate that policy should advocate increased
clinician knowledge about and time to promote breastfeeding.

Yang, Q., Wen, S. W., Dubois, L., Chen, Y., Walker, M. C., & Krewski, D. (2004).
      Determinants of breast-feeding and weaning in Alberta, Canada. J Obstet Gynaecol Can,
      26(11), 975-981.

This Canadian study assessed an array of variables affecting duration of breastfeeding in 1113
women. The authors did not differentiate between partial and exclusive breastfeeding. They
found that marital status, education, maternal smoking, and family income were all important
indicators of breastfeeding duration. This study simply provides me with more data supporting
the notion that a large number of factors influence breastfeeding duration and that this statement
is true worldwide.

Biological factors

Anderson, G. C., Moore, E., Hepworth, J., & Bergman, N. (2003). Early skin-to-skin contact for
      mothers and their healthy newborn infants. Cochrane Database Syst Rev(2), CD003519.

This review summarizes known information on the relationship between early mother-infant
contact and breastfeeding. Most studies have found a positive relationship between the two.
This finding establishes the importance of yet another factor in relation to breastfeeding duration.
It also provides guidance on design of effective hospital policies that aim to increase
breastfeeding rates.

Baker, J. L., Michaelsen, K. F., Rasmussen, K. M., & Sorensen, T. I. (2004). Maternal
       prepregnant body mass index, duration of breastfeeding, and timing of complementary
       food introduction are associated with infant weight gain. Am J Clin Nutr, 80(6), 1579-

This large study (n=3768) is especially useful because its subjects are also from the Danish
National Birth Cohort (DNBC). These researchers utilized a prospective study design, which
eliminated problems of retrospective bias. The authors found that decreased durations of
breastfeeding, as well as increased maternal body mass index (BMI) and earlier complementary
food introduction, led to greater infant weight gain in the first year of life. However, timing of
complementary food introduction was only significant when combined with breastfeeding
duration of < 20 weeks. Complementary food refers to infant foods other than breast milk or
formula. The authors lacked sufficient information to differentiate between exclusive and partial
breastfeeding, so they analyzed “any” breastfeeding. Their findings that maternal BMI and
duration of breastfeeding both have an independent effect on infant weight gain is especially
important given that the Hilson et al study (see below) found that increased maternal BMI led to
shorter breastfeeding duration. Thus, infants with mothers with high BMI are likely at increased
risk of greater weight gain through both mechanisms (maternal BMI and breastfeeding duration).

Dewey, K. G., Nommsen-Rivers, L. A., Heinig, M. J., & Cohen, R. J. (2003). Risk factors for
      suboptimal infant breastfeeding behavior, delayed onset of lactation, and excess neonatal
      weight loss. Pediatrics, 112(3 Pt 1), 607-619.

This study focuses on a range of biological factors that lead to decreased rates of breastfeeding.
The authors examine a mother’s success maintaining exclusive breastfeeding as their outcome.
In a cohort of 280 women, they find that maternal body mass index, primiparity (being a first
time mother), and delivery through cesarean section all increased the risk for breastfeeding
cessation. These findings are useful because they provide further evidence that a variety of
factors contribute to breastfeeding success and indicate that biology is at least one important
aspect of the process.

Hilson, J. A., Rasmussen, K. M., & Kjolhede, C. L. (2004). High prepregnant body mass index is
       associated with poor lactation outcomes among white, rural women independent of
       psychosocial and demographic correlates. J Hum Lact, 20(1), 18-29.

This study, conducted in upstate New York, evaluated obesity as an indicator for problems
initiating and continuing breastfeeding among 151 women. This study contained a relatively
large percentage (~ 40%) of women of low socioeconomic status. The researchers found that
obese women had fewer vaginal deliveries and entered lactogenesis II, the onset of high volume
milk production, later than normal. Elevated levels of progesterone, produced by excess adipose
tissue, may be the mechanism for this change. Notably, they found an even stronger relationship
between primiparity (first time mothers) and the late onset of lactogenesis II. This study
provides good evidence for the need for lactation support programs oriented toward first time
and obese mothers. Obesity as a risk factor is more relevant to the US than to Denmark, which
has lower rates of overweight and obesity in its population.

Nielsen, G. A., Thomsen, B. L., & Michaelsen, K. F. (1998). Influence of breastfeeding and
       complementary food on growth between 5 and 10 months. Acta Paediatr, 87(9), 911-917.

This Danish study followed 339 infants through their first 10 months of life. Researchers found
that infants breastfed for ≥ 7 months gained less weight and length. These infants also received
smaller amounts of cow’s milk, meat, and sweets (all complementary foods). These findings
reinforce the findings of Baker et al (described above). The authors emphasize that these results
should not be used to discourage long-term breastfeeding as the long-term effects of infant
weight gain and growth in the first year of life are not fully understood. Evidence indicates that
lower weight gain and growth may actually be a positive outcome. Infants with the highest
protein intake (indirectly, infants consuming the most meat) grew the most in the 10 months.
These researchers do not overtly differentiate between partial and exclusive breastfeeding, but
since they measure complementary food intake, they do assess this difference indirectly.

Patel, R. R., Liebling, R. E., & Murphy, D. J. (2003). Effect of operative delivery in the second
        stage of labor on breastfeeding success. Birth, 30(4), 255-260.

Researchers debate the effect of delivery by cesarean section on duration of breastfeeding. The
authors analyze this specific question, which hopefully adds important information to help
resolve the debate. They assess the effects of mode of delivery in 393 ]women from the UK and
use duration of exclusive breastfeeding as their outcome. Overall, the authors find no difference
in duration of breastfeeding between women who delivered vaginally and by cesarean section.
They do find that women who delivered by c-section and stayed in the hospital longer were more

successful breastfeeders. This finding makes sense; presumably these women received extra
support and instruction from hospital staff. Thus, this paper is useful because it indicates that
hospital actions and support may be more important than mode of delivery.


Albertsen, K., Andersen, A. M., Olsen, J., & Gronbaek, M. (2004). Alcohol consumption during
       pregnancy and the risk of preterm delivery. Am J Epidemiol, 159(2), 155-161.

This study utilized the Danish National Birth Cohort, and thus was mainly useful to me when I
was making decisions on coding variables. The authors characterized alcohol consumption in
the following categories: nondrinkers, one-half drink/wk, 1-1.5 drinks/wk, 2-3.5 drinks/wk, 4-6.5
drinks/wk, ≥ 7 drinks/wk. I utilized these categorizations initially, but used a different definition
of alcohol consumption (yes or no) in my final analyses. I did base my categorization of type of
alcohol on their definition: “preference for one type of alcohol was defined as beer, wine, or
spirits if the intake of this type exceeded 50 percent of the woman’s total alcohol intake” (p.156).
The authors found that wine drinkers were less likely to smoke and more likely to hold
professional level occupations, both of which corroborate my findings.

Goodwin, D. W., Gabrielli, W. F., Jr., Penick, E. C., Nickel, E. J., Chhibber, S., Knop, J., et al.
     (1999). Breast-feeding and alcoholism: the Trotter hypothesis. Am J Psychiatry, 156(4),

The authors evaluate the Trotter hypothesis, developed in the early 1800s, which posited that
early weaning led to alcoholism later in life. Subjects are 200 Danish infants from circa 1960,
who were followed for 30 years. Overall, they found that early weaning is a risk factor for
alcoholism in adulthood. Some evidence suggests that this correlation is related to the formation
of dopaminergenic mechanisms, which are important in addiction development. Unfortunately,
they lacked information on the mothers’ alcohol consumption status during pregnancy. This
study is useful because it focuses on a Danish population and provides further evidence about the
detrimental effects of attenuated breastfeeding duration.

Gronbaek, M. (2001). Factors influencing the relation between alcohol and mortality--with focus
      on wine. J Intern Med, 250(4), 291-308.

This article reviews the literature on alcohol to establish more clearly its effects on health.
Generally, most studies have found a J-shaped relationship between alcohol and mortality, which
suggests beneficial effects of alcohol in small doses. Some evidence indicates that wine confers
added benefits not found in other forms of alcohol. This article provides useful background
evidence for the evaluation of maternal consumption of alcohol during breastfeeding within my
study population, which has relatively high SES and predominately consumes wine.

Gronbaek, M., Di Castelnuovo, A., Iacoviello, L., Furman, K., Donati, M. B., de Gaetano, G., et
      al. (2004). Wine, alcohol and cardiovascular risk: open issue. J Thromb Haemost, 2(11),

This article argues that alcohol does have a protective effect against cardiovascular disease but
that the strength of this effect may vary by age, gender, and method of consumption.
Furthermore, the authors present evidence that wine may be the most beneficial type of alcohol
and discuss some possible mechanisms for this relationship. Some confounding factors include
lifestyle (including diet) and genetics. As in the other Gronbaek article, this article is useful as
background information for evaluating the implications of alcohol consumption in breastfeeding

Gunzerath, L., Faden, V., Zakhari, S., & Warren, K. (2004). National Institute on Alcohol Abuse
        and Alcoholism report on moderate drinking. Alcohol Clin Exp Res, 28(6), 829-847.
This report presents evidence on the risks and benefits associated with alcohol consumption in
different areas, one of which is breastfeeding. Much of the literature they review on alcohol and
breastfeeding come from Mennella. I discuss several of her specific studies below. Generally,
the authors here conclude that alcohol does not aid breastfeeding, as commonly thought, and that
mothers can reduce infant exposure to alcohol by waiting for a couple hours after alcohol
consumption to breastfeed. This source provides a useful summary of the literature in respect to
alcohol and breastfeeding.

Ho, E., Collantes, A., Kapur, B. M., Moretti, M., & Koren, G. (2001). Alcohol and breast
        feeding: calculation of time to zero level in milk. Biol Neonate, 80(3), 219-222.

This paper calculates rates of alcohol elimination in women of different body weights to help
breastfeeding women avoid exposing their infants to alcohol. Practical information such as
elimination rates is important since infants take twice as long as adults to eliminate alcohol and
the long-term effects of alcohol exposure in infants are unknown. Information presented in this
paper could be used to help develop practical policies and recommendations on alcohol
consumption in breastfeeding women.

Little, R. E., Northstone, K., & Golding, J. (2002). Alcohol, breastfeeding, and development at
        18 months. Pediatrics, 109(5), E72-72.

This study of 915 one year olds in the UK provides some evidence on short-term effects of
alcohol exposure on infant development. The authors did not find any developmental delays in
the study population. This negative finding may make sense if alcohol has small effects on
development or if these effects do not appear until later in life. The authors were trying to
replicate another study that did find motor deficits in one year olds exposed to alcohol. Thus, the
exact mechanisms and effects of alcohol exposure are still poorly understood. This paper
provides evidence that more research is needed before developing meaningful recommendations
for breastfeeding women.

Mennella, J. (2001). Alcohol's effect on lactation. Alcohol Res Health, 25(3), 230-234.

In this review Mennella asserts that contrary to popular belief, alcohol consumption may reduce
milk production. She presents evidence that infants exposed to alcohol may experience adverse
sleep effects and delays in gross motor development. Exposed infants may also develop early

positive emotional associations with alcohol. All of these findings indicate that breastfeeding
women should be cautioned against alcohol consumption. However, especially in the context of
my research, these findings must be balanced with social norms.

Mennella, J. A. (2001). Regulation of milk intake after exposure to alcohol in mothers' milk.
      Alcohol Clin Exp Res, 25(4), 590-593.

This study compared infant milk consumption after the mother consumed alcohol-containing
orange juice and regular orange juice in 12 dyads. After maternal alcohol consumption, infant
milk consumption decreased 20%. However, the infants made up for this deficit over the next 8-
12 hours. Outcomes for chronically alcohol-exposed infants are uncertain although some
evidence suggests that weight differences do not exist. This study presents important evidence
that alcohol consumption might be disruptive for breastfeeding. More evidence is needed for
conclusive recommendations.

 Mennella, J. A., & Gerrish, C. J. (1998). Effects of exposure to alcohol in mother's milk on
     infant sleep. Pediatrics, 101(5), E2.

In this study of 13 dyads, infant’s behaviors were monitored in respect to their exposure to
alcohol through breast milk. Infants were tested two different days. Each received regular breast
milk once and alcohol-containing breast milk once. This study is unusual in that it uses
experimental design to test effects of alcohol on infants. Ethical implications make it difficult
carry out a study design such as this one, but experimental studies often produce clearer findings.
The authors found that alcohol exposure decreases active sleep in the short term but that infants
make up for this deficit in the long run. Effects of chronic alcohol exposure are uncertain. These
findings provide a possible explanation for delays in gross motor development among infants
routinely exposed to alcohol (active sleep may be necessary for motor development). This study
provides cautionary evidence against the consumption of alcohol in breastfeeding women.

Mukherjee, R. A., Hollins, S., Abou-Saleh, M. T., & Turk, J. (2005). Low level alcohol
      consumption and the fetus. Bmj, 330(7488), 375-376.

This article argues that the only safe message in respect to alcohol consumption during
pregnancy is one of abstinence since the exact safe dose of ethanol is unknown. The authors
point out that differences in individual alcohol metabolism probably exist. This position is very
pertinent to Denmark, given that approximately half of Danish women consume alcohol during
breastfeeding. Alcohol seems to have more detrimental effects on the fetus than on infants.

Nielsen, N. R., Schnohr, P., Jensen, G., & Gronbaek, M. (2004). Is the relationship between type
       of alcohol and mortality influenced by socio-economic status? J Intern Med, 255(2), 280-

This Danish study examines mortality in relation to alcohol consumption in a cohort of 14223
individuals. The authors find that individuals consuming wine have higher levels of education
and income, which corroborates demographic findings in my study and provides added evidence
that alcohol consumption acts as an aggregate SES measure. Furthermore, they find that wine

has the strongest protective effect in lower SES groups. This finding may have important
implications for the interpretation of my results, especially given that my subjects are of higher
SES than is representative of the general Danish population.

Thackray, H., & Tifft, C. (2001). Fetal alcohol syndrome. Pediatr Rev, 22(2), 47-55.

This article provides good basic background information on the causes and characteristics of
fetal alcohol syndrome. It also briefly discusses the effects of alcohol on breastfeeding.
Interestingly, the authors note that alcohol inhibits prolactin and oxytocin release during
breastfeeding. Both these hormones produce a relaxing effect and are crucial to the success of
breastfeeding. Alcohol is also thought to be relaxing and thus conducive to breastfeeding.
However, this hormonal evidence suggests otherwise. This article provides good evidence
against alcohol consumption during pregnancy and questions the wisdom of it during


Agostoni, C., Marangoni, F., Grandi, F., Lammardo, A. M., Giovannini, M., Riva, E., et al.
      (2003). Earlier smoking habits are associated with higher serum lipids and lower milk fat
      and polyunsaturated fatty acid content in the first 6 months of lactation. Eur J Clin Nutr,
      57(11), 1466-1472.

This study analyzed the composition of breast milk among 92 Italian women who smoke. The
authors found that smoking changes fat content of breast milk. Notably, DHA levels were lower
in the milk from smoking mothers. DHA is an important fatty acid integral in brain
development. These results hold even if the smoking occurred earlier in pregnancy. This
research provides important evidence against smoking during pregnancy and breastfeeding and
implies that this behavior may have doubly negative effects on breastfeeding: changing
composition of milk on top of decreasing duration of breastfeeding (evidenced from my study
and others).

Batstra, L., Neeleman, J., & Hadders-Algra, M. (2003). Can breast feeding modify the adverse
        effects of smoking during pregnancy on the child's cognitive development? J Epidemiol
        Community Health, 57(6), 403-404.

This study presents an interesting dichotomy: even though smoking is detrimental to
composition of breast milk and duration of breastfeeding, breast milk may decrease other
negative effects of smoking that the infant experiences (such as brain development). The authors
studied 3162 children from the Netherlands and assessed their cognitive development through
their performance on reading, spelling, and math tests given at 9 years of age. Maternal smoking
only had a negative effect on children who had been bottle-fed. Genetics may play a
confounding role. This study provides encouraging evidence that breastfeeding can protect
against negative effects of maternal smoking. However, these findings may be difficult to
translate into practical interventions since women who smoke are less likely to successfully

Dahlstrom, A., Ebersjo, C., & Lundell, B. (2004). Nicotine exposure in breastfed infants. Acta
       Paediatr, 93(6), 810-816.

This Swedish study examined levels of nicotine exposure, through breast milk and infant urine
samples, in 40 infants. All infants were exclusively breastfed. The results of this study are
particularly relevant to my study since the subjects are Scandinavian. Infants whose mothers
smoked, took snuff, or were around second hand smoke had nicotine in their systems. The
authors make the pertinent observation that evidence is lacking on what a ‘safe’ dose of nicotine
is for infants and on how they metabolize nicotine. These findings could lead to conflicting
advice. From one perspective, breastfeeding may increase infants’ exposure to nicotine (through
breast milk and air). However, Batstra et al find that breastfeeding protects against negative
long-term effects from nicotine exposure. Clearly, the safest recommendation is for mothers to
avoid smoking, or other forms of nicotine, completely.

Ilett, K. F., Hale, T. W., Page-Sharp, M., Kristensen, J. H., Kohan, R., & Hackett, L. P. (2003).
         Use of nicotine patches in breast-feeding mothers: transfer of nicotine and cotinine into
         human milk. Clin Pharmacol Ther, 74(6), 516-524.

This study offers a practical solution for smoking, breastfeeding mothers who desire to reduce
their infants’ exposure to nicotine. In a population of 15 women, the authors found that 14 mg/d
or 7 mg/d patches significantly reduced nicotine levels in their milk (70% lower in those using 7
mg/d patches). Thus, this study provides practical evidence that can lead to the development of
realistic recommendations to improve maternal and infant health. Recommending nicotine
patches is probably more effective than is advocating total smoking cessation.

Sondergaard, C., Henriksen, T. B., Obel, C., & Wisborg, K. (2001). Smoking during pregnancy
      and infantile colic. Pediatrics, 108(2), 342-346.

This Danish study of 1820 mothers is directly pertinent to my study population. The authors
found that smoking during pregnancy led to higher risk of infant colic. Breastfeeding did not
modify this relationship. Thus, this research provides evidence on the detrimental effects of
smoking but fails to add to evidence on the benefits of breastfeeding. Also, this study would be
more useful for me if the authors had evaluated smoking during breastfeeding instead of during


Aljazaf, K., Hale, T. W., Ilett, K. F., Hartmann, P. E., Mitoulas, L. R., Kristensen, J. H., et al.
       (2003). Pseudoephedrine: effects on milk production in women and estimation of infant
       exposure via breastmilk. Br J Clin Pharmacol, 56(1), 18-24.

This study used a small sample of women (n = 8) to determine detrimental effects of
pseudoephedrine (cold medication) on breast milk. The authors found that milk production
decreased 24% after giving the mothers the medications. They propose that the mechanism for
the change may be decreased prolactin (hormone) production. Infants were exposed to 4.3% of

the maternal dose through breast milk. This study is useful because it helps elucidate the specific
effects of one medication, which in turn can help guide policy and practice. Cold medication is
quite commonly used, so it is important to understand its effects on both mother and infant in
respect to duration of breastfeeding.

Chaves, R. G., & Lamounier, J. A. (2004). [Breastfeeding and maternal medications]. J Pediatr
      (Rio J), 80(5 Suppl), S189-198.

This review provides a helpful summary of the studies done of various medications and
breastfeeding from 1993 to 2004. Generally, the effects of medications on breastfeeding are
poorly understood, especially because it is unethical to do controlled studies in this area. The
paper provides useful tables that list specific drugs and their compatibility levels with
breastfeeding. In respect to mental health drugs, many of the effects on either breast milk
production or the infant are unknown but potentially concerning. This information is especially
pertinent because of the high prevalence of postpartum depression. Ideally, physicians can
simultaneously treat postpartum depression (with medications, if necessary) and encourage
breastfeeding without compromising the health of either mother or child. If they must choose
either breastfeeding or medicating for postpartum depression, this scientific evidence is
important to help physicians and mothers understand the costs and benefits of each.

Hallberg, P., & Sjoblom, V. (2005). The use of selective serotonin reuptake inhibitors during
       pregnancy and breast-feeding: a review and clinical aspects. J Clin Psychopharmacol,
       25(1), 59-73.

This Swedish study provides evidence for a postpartum depression prevalence of 10-16% in
Scandinavian populations. Only limited evidence is available on the safety of serotonion
reuptake inhibitors (SSRIs) during pregnancy and breastfeeding, so this paper reviews both
animal and human studies to provide a comprehensive view of the evidence. The authors
provide a useful overview table of all the results. Overall, they conclude that risks associated
with SSRIs are low and possibly lower than those associated with tricyclic antidepressants.
However, they point out that generally more studies and information are needed. As noted in the
annotation for Chaves and Lamounier, researchers must strive to understand the effects of
depression medications on women, infants, and breast milk because of the high prevalence of
depression in this population.

Hendrick, V., Smith, L. M., Hwang, S., Altshuler, L. L., & Haynes, D. (2003). Weight gain in
        breastfed infants of mothers taking antidepressant medications. J Clin Psychiatry, 64(4),
This study of 78 breastfeeding mothers examines whether depression medications affect infant
weight. They found that maternal antidepressant use was not related to infant weight but that
infants with mothers suffering from long-term depression weighed significantly less. Thus, this
study provides an important indication that postpartum depression has negative effects on infant
health aside from duration of breastfeeding. The findings also imply that depressed women can
safely take antidepressants and breastfeed simultaneously.

Howard, L., Webb, R., & Abel, K. (2004). Safety of antipsychotic drugs for pregnant and
      breastfeeding women with non-affective psychosis. Bmj, 329(7472), 933-934.

 This review does little to add to my knowledge on the effects on psychiatric medications during
breastfeeding. The authors do advocate large cohort studies since randomized trials are
unethical. They also make the useful point that new drugs are emerging rather quickly, which
makes it difficult to adequately assess all of them in respect to breastfeeding. Most infants
exposed to antipsychotic medications have not shown adverse effects.

Ilett, K. F., Kristensen, J. H., Hackett, L. P., Paech, M., Kohan, R., & Rampono, J. (2002).
         Distribution of venlafaxine and its O-desmethyl metabolite in human milk and their
         effects in breastfed infants. Br J Clin Pharmacol, 53(1), 17-22.

This study focuses on one drug only, Venlafaxine, a novel bicyclic phenylethylamine
antidepressant. This drug seems to avoid side-effects of both tricyclic antidepressants and
SSRIs. The authors performed a small study, using only six women, all of whom were taking
Venlafaxine. The results indicate that use of the drug while breastfeeding is safe. The authors
found no adverse effects in the infants but did recommend careful monitoring of the drug levels
in infants, especially very young ones that might metabolize the drug more slowly. They do not
assess the effectiveness of Venlafaxine, compared to other antidepressants, in treating
postpartum depression.

Ito, S., & Lee, A. (2003). Drug excretion into breast milk--overview. Adv Drug Deliv Rev, 55(5),

This review paper, like Chaves and Lamounier, summarizes knowledge on effects of drugs on
breastfeeding. However, the authors here also summarize the benefits of breastfeeding, trends in
breastfeeding initiation, and prevalence of medication use in breastfeeding women. They state
that 90% of women take some sort of medication in the first week postpartum. Clearly then,
understanding the effects of medications on breastfeeding is extremely important. They also
point out that many women fear exposing their infants to drugs and as a result will either stop
breastfeeding or stop taking their medications. This important point emphasizes the need for
maternal education in respect to medication use during breastfeeding. The authors also provide a
helpful discussion of drug delivery systems and of drug build up in the body. They provide a
small reference table of the effects of various drugs in infants.

Weissman, A. M., Levy, B. T., Hartz, A. J., Bentler, S., Donohue, M., Ellingrod, V. L., et al.
      (2004). Pooled analysis of antidepressant levels in lactating mothers, breast milk, and
      nursing infants. Am J Psychiatry, 161(6), 1066-1078.

This review includes studies from as far back as 1979. Not only do the authors report the results
found in the studies, they perform their own aggregate analysis on all of the data from them.
This method takes advantage of information that can be gained from large numbers of subjects.
They conclude that three specific antidepressants – nortriptyline, paroxetine, and sertraline – are
the safest for breastfeeding women. Like the other papers, though, they emphasize the need for
careful monitoring of infants exposed to antidepressants. The authors reference the infant’s

immature hepatic (liver) function during the first few weeks as a possible cause for concern.
These infants may be biologically unable to process the medications. This paper cites 13% as
the rate of postpartum depression.

Breastfeeding policies

Ahluwalia, I. B., Tessaro, I., Grummer-Strawn, L. M., MacGowan, C., & Benton-Davis, S.
      (2000). Georgia's breastfeeding promotion program for low-income women. Pediatrics,
      105(6), E85.

The authors of this study assess the efficacy of five breastfeeding promotion strategies
implemented in Georgia in 1991. These strategies targeted low-income women (those on WIC)
and are “1) enhanced breastfeeding, 2) breast pump loans, 3) hospital-based programs, 4) peer
counseling, 5) community coalitions” (p. 85). The paper provides a detailed description of each
strategy. The authors use a combination of survey data and focus groups to gather both
quantitative and qualitative data. This comprehensive approach enhances the usefulness of their
findings. Although non-WIC participants breastfed more, they found that breastfeeding
initiation rates increased more (from 1992-1996) for those in the WIC program. Women who
were younger, had no college education, unmarried, and black experienced the largest increases
in initiation. This finding is positive and indicates that the program is successful in reaching its
target group. The demographics of the women in this study are quite different from those in the
Danish National Birth Cohort; thus, strategies used here may not be useful in a Danish
population. However, this study provides useful comparative information.

Arthur, C. R., Saenz, R. B., & Replogle, W. H. (2003). The employment-related breastfeeding
       decisions of physician mothers. J Miss State Med Assoc, 44(12), 383-387.

This study assesses the breastfeeding behavior of female physicians in Mississippi. Generally,
other studies have found a positive correlation between duration of maternity leave and
breastfeeding. Data on this specific profession is important because physicians are highly
educated and probably more likely to understand the benefits of breastfeeding than even other
professionals. However, they work in a demanding profession that allows little time for
maternity leave. The authors find that like women in other professions, physicians who return to
work full time wean their infants early. This finding provides compelling evidence for the need
for good maternity leave policies.

Cattaneo, A., Borgnolo, G., & Simon, G. (2001). Breastfeeding by objectives. Eur J Public
       Health, 11(4), 397-401.

This Italian study assesses the effectiveness of financial penalties in respect to increasing
breastfeeding rates. The authors measured exclusive, predominant and complementary
breastfeeding; the range of types of breastfeeding included increases the usefulness of the study.
In 1998 and 1999 in northeastern Italy, as a part of programs promoting breastfeeding, local
health authorities faced financial penalties for not reaching objectives. Results suggest that these

penalties were effective. This study poses a relatively novel method of breastfeeding promotion
and one that is very feasible. Thus, it adds important information on effective policy.

Coffin, C. J., Labbok, M. H., & Belsey, M. (1997). Breastfeeding definitions. Contraception,
       55(6), 323-325.

This paper is extremely important as it provides standardized definitions of types of
breastfeeding. Without the use of standard definitions, research would not be comparable and
thus would be relatively useless. The authors visually depict this categorization, which experts
devised at a meeting of the Interagency Group of Action on Breastfeeding in 1988.

DiGirolamo, A. M., Grummer-Strawn, L. M., & Fein, S. (2001). Maternity care practices:
       implications for breastfeeding. Birth, 28(2), 94-100.

This study analyzes the efficacy of five of the steps in the Baby Friendly Health Initiative (BFHI)
in a population of 1085 US women. The outcome is breastfeeding beyond 6 weeks;
breastfeeding included any amount of breast milk. This research is important because the BFHI
has received much attention as an important initiative and is currently one of the few large-scale
efforts to improve breastfeeding rates. Thus, scientists, physicians, and policy makers need to
understand the efficacy of the program as well as variations in efficacy among populations.
Here, the authors found that few women experienced all five of the steps assessed. Those who
experienced none of the steps were eight times more likely to stop breastfeeding before six
weeks than those who experienced all five. This study is not directly relevant to a Danish
population but provides useful US data for comparison.

Galtry, J. (2003). The impact on breastfeeding of labour market policy and practice in Ireland,
        Sweden, and the USA. Soc Sci Med, 57(1), 167-177.

This paper asserts that policy can enable both breastfeeding and women’s participation in the
labor market. Few researchers have focused on this topic so far, so the information provided
here is quite valuable. Also, because the authors comparatively analyze three different countries,
they can assess cultural influences. Overall, lactation programs seem to be cost-effective. Each
country utilizes different policies and has different problems they need to overcome. Thus, this
paper will be helpful for the comparative aspect of my policy discussion.

Hector, D., & King, L. (2005). Interventions to encourage and support breastfeeding. N S W
       Public Health Bull, 16(3-4), 56-61.

This article is quite useful because it analyzes breastfeeding interventions at multiple levels –
from individual to societal. Based on a conceptual framework, the authors include individual
knowledge, attitudes, and skills, hospital and health services environment, home/family/friends
environments, work environment, community environment, and societal norms and expectations.
The authors emphasize the complexity of factors that contribute to breastfeeding success. As a
result, complex, multi-level interventions are needed.

Hofvander, Y. (2003). Why women don't breastfeed: a national survey. Acta Paediatr, 92(11),

Hofvander, a Swedish child health expert, presents several arguments for the lack of
breastfeeding on an international level. First, he asserts that the WHO recommendation that
women breastfeed exclusively for six months is unrealistic and fails to account for social and
economic constraints. He cites year long maternity leaves in Scandinavia as a direct cause of
extended breastfeeding durations and then points out that in most countries, maternity leave is a
maximum of three months. He also mentions the Baby Friendly Hospital Initiative as an
important policy. After its implementation in Sweden, breastfeeding at six months postpartum
increased from 50% to 73%. Overall, though, Hofvander emphasizes the multifactorial nature of
breastfeeding duration. This paper provides a useful overview of important breastfeeding policy
considerations and also includes some Scandinavia specific references.

Kovach, A. C. (1996). An assessment tool for evaluating hospital breastfeeding policies and
      practices. J Hum Lact, 12(1), 41-45.

This paper describes a method for evaluating the effectiveness of the Baby Friendly Hospital
Initiative in specific hospitals where it has been implemented. Most of the article focuses on
describing the actual assessment instrument, which is not directly relevant to my research.
However, it is useful to have a background knowledge of how policies are evaluated.

Kovach, A. C. (1997). Hospital breastfeeding policies in the Philadelphia area: a comparison
      with the ten steps to successful breastfeeding. Birth, 24(1), 41-48.

This paper analyzes the extent to which BFHI steps have been implemented in 28 hospitals in the
Pennsylvania Delaware Valley. Overall, the study provides good evidence that the US needs
more aggressive implementation of breastfeeding promotion programs. Most hospitals in the
study had only implemented four of ten steps. This paper emphasizes the dramatic difference in
average hospital policy between Denmark and the US.

Kramer, M. S., Chalmers, B., Hodnett, E. D., Sevkovskaya, Z., Dzikovich, I., Shapiro, S., et al.
      (2001). Promotion of Breastfeeding Intervention Trial (PROBIT): a randomized trial in
      the Republic of Belarus. Jama, 285(4), 413-420.

This study evaluates the effectiveness of the BFHI in respect to breastfeeding duration and
exclusivity as well as infant morbidity. The results may not be directly applicable to a Danish
population since the study occurred in an eastern European population. However, the study is
unique in its use of a randomized trial design. This randomization of experimental sites leads to
results that are more clearly interpretable. Overall, the authors found that infants at Baby
Friendly sites had lower morbidity rates and higher breastfeeding rates. Thus, it provides good
evidence on the usefulness of the BFHI as a breastfeeding promotion policy.

Merewood, A., & Philipp, B. L. (2000). Becoming Baby-Friendly: overcoming the issue of
     accepting free formula. J Hum Lact, 16(4), 279-282.

As part of the BFHI, hospitals must pay fully for formula. This stipulation is based on the
economic rationale that hospitals and employees will be more reluctant to offer formula if they
have to cover its costs. This paper describes the efforts of Boston Medical Center to comply
with this requirement. For hospitals struggling to reject free formula, the authors provide useful
information. However, free formula is not as relevant an issue in Denmark since national policy
forbids hospitals from accepting it. Thus, free formula is an issue on which Denmark and the US
are distinctly different.

Ortiz, J., McGilligan, K., & Kelly, P. (2004). Duration of breast milk expression among working
        mothers enrolled in an employer-sponsored lactation program. Pediatr Nurs, 30(2), 111-

In this study, the authors assess the importance of supportive work policies for breastfeeding
success. Their subjects are 462 US women employed by five corporations that support lactation
through breastfeeding education classes, certified lactation consultants, and equipped private
rooms for pumping milk. Overall, employee programs seemed very useful. Women pumped for
an average of 6.3 months. Most women were full-time and had had 2.8 months of maternity
leave. Hourly-wage women were less likely to take advantage of the program, which indicates
that these women may need to be more aggressively targeted. Employee programs are especially
important for US populations, where women have very low levels of guaranteed maternity leave
(unlike Denmark).

Philipp, B. L., Malone, K. L., Cimo, S., & Merewood, A. (2003). Sustained breastfeeding rates at
       a US baby-friendly hospital. Pediatrics, 112(3 Pt 1), e234-236.

This paper is a case study of Boston Medical Center (BMC). Subjects are 200 infants from
2000-2001. The authors found that in the first year of Baby Friendly status, breastfeeding
initiation rates increased form 58% to 86.5% and that these rates were sustained for the next two
years. A strength of this study is that the authors differentiate between exclusive and partial
breastfeeding. Overall, the authors present good evidence that the BFHI can be effective in the
US. This data is potentially useful for comparisons with breastfeeding initiation rates in Danish

Rowe-Murray, H. J., & Fisher, J. R. (2002). Baby friendly hospital practices: cesarean section is
     a persistent barrier to early initiation of breastfeeding. Birth, 29(2), 124-131.

This Australian study (n = 203) specifically focuses on caesarean delivery as an obstacle to
breastfeeding. In my study population, mode of delivery did have a significant effect on duration
of both partial and exclusive breastfeeding, but the effect size was very small. However, the
importance of delivery method may vary by country. The authors found that women who
delivered by c-section were delayed in breastfeeding initiation. This outcome, though, was more
related to hospital practices than biological effects of surgical delivery. Thus, hospitals must
work to get infants to their mothers more quickly after delivery.

Syler, G. P., Sarvela, P., Welshimer, K., & Anderson, S. L. (1997). A descriptive study of
        breastfeeding practices and policies in Missouri hospitals. J Hum Lact, 13(2), 103-107.

The authors analyzed the extent to which Missouri hospitals comply with the BFHI. This study
objective is very similar to that of Kovach (1997), except in a different state. None of the
Missouri hospitals fully complied with the BFHI. Consequently, this study provides more
compelling evidence that US hospitals have a serious need for improvement in respect to
breastfeeding policies. This situation contrasts starkly with high levels of breastfeeding support
in hospitals in Denmark.

Tully, M. R. (2005). Working and breastfeeding. AWHONN Lifelines, 9(3), 198-203.

This article focuses on providing practical advice to both employees and employers on how to
increase the prevalence of breastfeeding. The author advocates pumping as a useful strategy.
Although this paper does not provide me with much new information, it does give me an
example of the current distribution of information to women and employers.

WHO. (1991). Indicators for assessing breastfeeding practices, Geneva, Switzerland (No. 91.14).

Like the Coffin et al paper, this report defines different types of breastfeeding. It also
summarizes methods that are useful for assessing different types. These breastfeeding
definitions largely agree with the ones presented in Coffin et al. The establishment of
standardized nomenclature is necessary to make the study of breastfeeding a respected science.
Both of these papers guided my definitions of exclusive and partial breastfeeding.

Yngve, A., & Sjostrom, M. (2001). Breastfeeding determinants and a suggested framework for
      action in Europe. Public Health Nutr, 4(2B), 729-739.

This article summarizes recent international documents advocating breastfeeding: the Innocenti
Declaration, the Baby-Friendly Hospital Initiative, the WHO international Code of Marketing of
Breast Milk Substitutes, and Healthy People 2010. They also summarize the positions of the
European Union, WHO/UNICEF, the British Paediatric Association, Swedish concerted action,
the American Academy of Pediatricians, the American Dietetic Association, and the ILO
Maternity Protection Convention. Next, they review the determinants of breastfeeding as they
fall into five categories: socio-demographic, psycho-social, health care related, and community-
and policy attributes. The authors emphasize the need to continue research on and fully
understand these factors. Finally, they propose a common surveillance system that would
promote studies from local to supranational levels. The authors also emphasize the need to
develop EU-wide breastfeeding promotion programs, especially ones that target risk groups
(young, low-income, uneducated mothers).