Prenatal Development, Birth, and the Newborn Baby Prenatal Development begins at conception. Ovum is largest cell in the body, sperm is one of the smallest. Conception occurs when an egg has erupted from the ovary (as it will every 28 days) and is fertilized in the fallopian tubes or womb. Hormones are released to prepare the lining of the womb for implantation of the zygote. If there are abnormalities or faulty implantation, zygote will be shed 2 weeks later with menstrual flow with the mother never knowing she was pregnant. (One of the criticisms of the IUD as a form of birth control was that it would prevent implantation, but the woman would conceive and that was considered by some people to be abortion of a viable baby) Sperm live for 6 days in the woman’s environment, but the egg only lasts 1 day after entering the fallopian tube. Most pregnancies occur within 3 days around ovulation. Periods of development are measured in trimesters, each being 3 months. First trimester: Zygote is the period of fertilized cell multiplying into a blastocyst during the first 2 weeks. The end of this stage is implantation. o Implantation occurs between 7 and 9 days after fertilization. The outer membrane becomes the amnion. As many as 30% of zygotes do not survive, often due to abnormalities. o Amnion encloses the developing zygote in amniotic fluid which cushions the baby from trauma. o Placental and Umbilical cord Chorion surrounds the amnion and form fingerlike villi, blood vessels. Placenta is an organ that connects the mother’s and embryo’s blood system, permitting food and Oxygen to pass through to the baby, and waste to be carried off. A membrane screens some toxins but not all. Umbilical cord connects the placenta to the baby, containing one large vein that brings in blood loaded with nutrients and 2 arteries that remove waste products. Embryo period lasts from the 2nd through 8th week, until the bones begin to form. Cell differentiation is occurring at this point, and we still don’t know what triggers an ambiguous cell to become a specific type of cell. o The embryonic disc separates into: Ectoderm- becomes the CNS and skin Mesoderm- becomes the muscles, skeleton, circulatory system, internal organs. Endode rm- becomes the digestive system, lungs, urinary tract, glands o Neural tube development happens as the ectoderm folds over to form a neural tube, later to become the spinal cord and brain. o Sense organs develop in the 2nd month- eyes, ears, nose. Arms, legs and neck and jaw form, as well as internal organs, heart, liver a nd spleen. Fetus period lasts from 2 mo. to birth. There is rapid growth overall- faster than any other period in life. o Third month- now the fetus is responsive, showing early behaviors of sucking, kicking, and a preview of lungs expanding. The gender of the baby can be detected by ultrasound by the 12 th week. Heartbeat can be detected. o Second trimester-by 17 – 20 weeks the mother can detect movement. Vernix is a cheeselike substance that protects baby’s skin from chapping from the amniotic fluid. Lanugo is a downy hair that holds the vernix to the skin. Neural development is occurring, producing more neurons than you can use in your lifetime. Glial cells support and feed the neurons develop. By 20 weeks the baby can show responses to irritation or stimulation. (During a fetoscopy, the light shines in the baby’s eyes, so they will try to shield their eyes with their arms and hands. Amazing. o Third trimester Age of viability is the point at which the fetus can first survive if born. It varies from 22 to 26 weeks. They will need much help to survive, incubator, help with breathing. Pres. Kennedy’s baby Patrick would have survived if he had been born today, but in the 1960’s there wasn’t enough technology to overcome his hyaline membrane disease. The brain’s organization is developing to the point that the fetus shows alertness and sleep states. Fetal personality will link to prenatal behavior. Very active babies before birth are often difficult babies, with irregular schedules. They can feel pain by 24 weeks and react to sound with body movements. They show a preference for mom’s voice and after birth will suck harder to turn on a recording of mom’s voice (particularly if the baby has been conditioned on mom’s voice reading a story to the baby before birth – Dr. Seuss) Babies will grow a laye r of fat in the last month that will aid baby in regulating body temperature. Also immunities are being deposited in the baby’s system to protect against illness. Prenatal Environmental Influences Sensitive periods of development relate to the particular time of critical development of an organ system. If there is an insult during that time, development may be impacted permanently. Teratogens are environmental agents that can cause damage to the developing fetus. Later in development, exposure to these agents may do little harm. It’s also possible to suffer later effects of a drug exposure. Baby girls exposed to DES, given to mothers to minimize miscarriage, had high risks for vaginal cancer and malformations of the womb in adulthood- a risk not explored in drug testing. o Drugs, even prescription drugs, can have impacts on development. Any drug taken by the mother that has a molecule small enough to penetrate the placental barrier can affect the fetus. Even aspirin can relate to low birth weight, increased mortality, lower IQ and poorer motor development. Even caffeine links to low birth weight, miscarriage, withdrawal symptoms in the baby such as irritability, vomiting. Prescription- This was tragically seen with thalidomide, used to sedate mothers, but producing gross deformities in limbs, ears, heart, kidneys, & genitals. Illegal drugs Cocaine produces drug-addicted babies with multiple problems- prematurity, low birth weight, defects, breathing problems, death at birth. These babies cry is so shrill that it affects the caregivers. It may devolve into attachment problems if the mother can’t care for the infant adequately. There are affects to the blood vessels and oxygenation of the baby after a dose, which can permanently affect neural development. Motor and language functions are affected. Crack babies have the most serious problems. Unfortunately these babies’ problems don’t end with birth, since their mothers are usually unable to adequately care for them. Marijuana relates to low birth weight, prematurity. Heroin/ methadone produces addicted babies, less responsive, with poor motor development. o Smoking exposes babies to tobacco and produces low birth weight, miscarriage, impaired breathing, greater mortality risk, cancer later in childhood. It also puts the mother at increased risk of bleeding. These babies seem to have shorter attention spans, poorer memories, lower IQ scores and more behavior problems later. Nicotine constricts blood vessels, so nutrients and oxygen are in shorter supply to the baby. Also it increases carbon monoxide in the baby’s blood. That affects CNS development. Even passive smoke exposure affects the baby. o Alcohol is the single greatest cause of birth defects and is completely preventable. The effects on the baby are permanent, even if the baby gets a rich environment after birth. The brain is permanently affected in structure and function. The brain simply did not get enough oxygen to develop. Even one drink per day has affects on fetal development and growth. Fetal alcohol syndrome (FAS) is the severe form of the impairments due to mother’s drinking. It shows as mental retardation, impaired coordination, attention problems, impaired memory and language, hyperactivity. There are particular facial abnormalities and small skull and brain. Fetal alcohol effects (FAE) is a milder form yet there are significant impairments in learning potential. o Radiation effects were clearly seen after Hiroshima, Chernobyl. A great many babies miscarried, others were born with underdeveloped brains, deformities, slow growth patterns. There may be heightened risk to the baby of childhood cancer, lower IQs, learning and emotional disorders. o Pollution Mercury- effects of exposure are physical deformities, mental retardation, speech impairments, motor problems. Lead – effects are prematurity, low birth weight, brain damage, physical defects. PCBs- low birth weight, discolored skin, deformities of gums, nails, brain waves, poor cognitive development. o Infectious diseases Rubella – German measles in the mother during sensitive periods in fetal development results in heart defects, eye cataracts, deafness, internal abnormalities, mental retardation. HIV & AIDS is passed to a fetus 20 – 30% of the time. It causes weight loss, diarrhea, respiratory illness, brain damage. Most babies survive only 5 – 8 months once symptoms appear. If the mother uses AZT, it reduces transmission to the baby 95%. Unfortunately, in Africa, most clinics have no access to these life- saving drugs, so babies are born infected and soon die. Herpes results in infection of baby during birth, miscarriage, low birth weight, malformations, mental retardation. Toxoplas mosis is contracted from cat feces or undercooked meat. If the baby is exposed during a critical period, it can cause brain and eye damage. Prenatal Environment and later health o Low birth weight and CVD- infant’s poor weight gain results in cardiovascular disease in adulthood. Poor nutrition can also result in diabetes by affecting pancreas function. Stress hormones from the mother may also retard fetal growth, increase blood pressure and produce hypoglycemia. Low weight gain often is compensated by later weight gain that predisposes to diabetes. o High birth we ight and breast cancer – high birth weight in babies relates to later breast cancer. It seems to be due to high levels of estrogen during pregnancy which affects breast tissue development. o Prevention occurs as we care for our health in a thoughtful way as we have control over eating, exercise, preventive medicine. Other maternal factors o Nutrition- during a healthy pregnancy, mom will gain about 25-30 pounds. If the baby is malnourished, there is serious damage to the CNS, seen in lower brain weight. It will also affect other organ system development, especially the immune system, resulting in frequent illness. Lack of folic acid particularly affects neural tube formation, showing up as anencephaly or spina bifida. o Stress relates to miscarriage, prematurity, low birth weight and baby irritability, respiratory illness, GI tract problems. It also relates to cleft palate and pyloric stenosis which affects nutritional intake. Stress hormones shift blood flow from the body to the brain and reduces oxygenation. Stress also affects immunity, increasing illne ss. o Rh Factor Incompatibility occurs when the mother is Rh- negative but the baby is Rh-positive. The mother’s body will form antibodies to fight the foreign blood protein being produced by the baby. It can reduce oxygenation to the baby. First babies are usually not affected, but the risk occurs to later pregnancies. There is a vaccine given to the mother of a positive baby to prevent buildup of antibodies. Blood transfusions may be necessary after birth. o Maternal age/ previous births can affect ability to get pregnant or chances of having a baby with chromosomal defects (Downs syndrome) but other complications are no more prevalent in older mothers. Prenatal health care is essential to make sure the mother is not developing serious problems, such as toxemia where the blood pressure increases, with swelling in the extremities. Mother may need to go to bed to avoid serious effects. Many women delay seeing a doctor,, particularly younger mothers or impoverished mothers. Their babies have more problems as a result. Childbirth Stages of childbirth o Dilation and effacement of the cervix- longest stage of labor, lasting 12 to 14 hours, as the contractions of the uterus stretch open the cervix. o Birth only lasts 20 – 50 minutes as the mother pushes the baby out. o Delivery of placenta occurs with a few final pushes, as it separates from the wall of the uterus, its job done. Baby’s adaptation to birth is facilitated by the baby’s own stress hormones. They send a rich supply of blood to the brain and heart. They also help the baby to breathe better as the lungs absorb extra fluid, and expand the bronchial tubes. They also arouse the infant into alertness. Newborn’s appearance: about 20 in. long, 7.5 pounds, head large in comparison to body. Often their heads are misshapen from time in the birth canal. But they have round faces, fat cheeks and big eyes, which make adults bond and cuddle them. Apgar scale ranges from 0 to 2 on each measure, giving an overall score of up to 10 points. A baby who scores less than 7 is in distress; less than 4, is in serious trouble and needs emergency attention. o Heart rate o Respiratory effort o Reflexes o Muscle tone o Color Approaches of Childbirth have changed a lot in Western society, as medical science has improved and childbirth is considered a medical condition, not a natural part of life to be dealt with in the home. Today birth centers allow medical intervention as necessary, but family members can be present for the birth. Some women still birth at home. Natural, prepared childbirth is a variety of techniques that help reduce pain and make childbirth rewarding and involving of other family members. o Classes about labor and delivery to reduce anxiety. o Relaxation and breathing training counteract pain. o Labor coach is often the father, who helps mom to relax, breathe, offers massage and emotional support. The father feels more involved and it aids bonding for the dad. Home delivery o Nurse-midwives have degrees in nursing and training in childbirth. This allows for a more personal birth environment, but the baby could be at risk if it has problems. Medical interventions may be necessary if the baby is in distress during birth. A baby trapped too long in the birth canal can develop cerebral palsy due to lack of oxygen. o Anoxia puts babies at risk for neural damage that can be permanent. o Breech position is when the baby is turned feet first. The cord may be wrapped around the baby’s neck and constrict blood/ oxygen flow. Often a cesarean section is the choice in this condition. o Fetal monitoring tracks the baby’s heart rate during labor. If the baby shows distress, surgery may be required. This monitor can be on the mother’s stomach, or threaded through the birth canal and pasted on the baby’s head. o Labor and delive ry medication is used in 80+% of births. Analgesics reduce pain. Anesthetics are stronger pain killers that block pain. Spinal blocks can completely numb the body below the waist. These drugs can weaken contractions and interfere with the mother pushing. They may leave the baby druggy, without the interest or ability to suck for awhile. o Cesarean Delivery is a surgical birth through the abdomen. 20% of births in US and Canada are this way. It is used for Rh incompatibility, separation of the placenta, maternal illness such as herpes2, breech births. Recovery is longer for the mother, and the baby may be less responsive. Preterm and Low-Birth-Weight babies are less than 5.5 pounds or before 38 weeks gestation. 1/14 babies in US is born underweight. The poor, the teen mothers have the greatest risks. Preterm babies are born weeks before their due date. They may or may not be underweight. Small for Date babies are below normal weight. Some may be full term, others are preterm. These babies have more serious problems, higher mortality, more chance of brain damage, lower IQ scores later, problems with attention. Consequences in caregiving for preterm babies are that they are treated more delicately, held less often, less closely & are at higher risk for abuse, as parents may be frustrated by the baby’s unresponsiveness. Inte rventions for preterm babies o Isolette is a temperature-controlled bed that filters air to enable their lungs to function. These babies are at risk for respiratory distress syndrome because their lungs are poorly developed. o Special infant stimulation such as a hammock, waterbed, music, or tapes of the mother’s voice promote weight gain and greater alertness. Massage also increases weight gain and advanced IQ and motor function. Kangaroo care is carrying the baby between the mother’s breasts to regulate temperature and stimulate oxygenation and sleep. o Training pare nts in caregiving allows the parents to feel more confident in caring for their babies. With coaching, even impoverished or uneducated parents can do a good job enabling their babies to develop as much as possible. Most programs stop the interventions early in life, though, and studies are finding these children need interventions to sustain development past age 3, even into the school years. Infant mortality assesses the health of a nation’s children. It assesses deaths in the first year of life per 1,000 live births. In spite of technological advances, the US is only 24 th in infant morality in the world. African-American babies are at greatest risk in the US (twice as likely to die in the first year as white babies in US) Neonatal mortality is the rate of death within the first month of life (67% of infant death rate). It may be due to serious physical defects at birth, or low birth weight. In countries with lower mortality rates, the parents have assistance in staying home after birth. Studies have shown that 6 weeks of paid leave is not enough to enable healthy development. 12 weeks is associated with better outcomes. Single mothers have the least chance of that kind of support. SIDS (Sudden Infant Death Syndrome) is the unexpected (and often unexplained) death, often during the night, of an infant under 1 year of age. SIDS is the leading cause of infant mortality between 1 and 12 months of age. These babies often have problems at birth, low birth weight, prematurity, low Apgar scores, abnormal heart rate or respiration. The hypothesis is that there is impaired brain function that does not respond when survival is threatened, such as if the baby stops breathing. This usually alerts the brain when oxygen levels drop to a certain point in the blood, to gasp and breathe. These are reflexive responses, yet they don’t develop effectively in these babies. These babies simply give in to oxygen deprivation and die during the night, without a whimper. Related factors: maternal smoking, prenatal abuse of drugs such as opiates or barbiturates (increases SIDS risks 10 times), sleeping on their stomachs, wrapped up in too many blankets, so they stay too warm. These factors contribute to sleep deprivation, so when babies rebound and sleep deeply, their airways may collapse and the baby won’t arouse at loss of air. Babies sleeping on soft bedding inhale their own CO2 and die from lack of oxygen, too. Parents often suffer unmollified grief, feeling they should have done something, yet they didn’t know what to do. Birth complications can result in later death, but quality of home environment makes a difference here. Even moderately stressed children, given high quality home environments do well on IQ and adjustment scales later. Babies who were pretty and had positive personalities also received more positive responses from adults that enabled better development. There are bidirectional impacts on baby and parents from each person’s personality and responsiveness. Newborn baby’s capacities Newborn reflexes are inborn, automatic responses to a particular stimulation. Some reflexes have survival value: Rooting reflex, sucking. Other reflexes form the basis of later functions: Stepping reflex, swimming reflex, palmar grasp, tonic neck reflex. Sucking also promotes interaction with parents or self- soothing. Most reflexes fall out between 2 and 4 mo., as voluntary responses develop in accord with more controlled brain function. Newborn States of Arousal are degrees of sleep and wakefulness. o Sleep is the most common state of the newborn, 16+ hours a day. Rapid eye-movement sleep (REM) associates with a brain wave rhythm that is much like wakefulness, with twitches and moves. This seems to be the brain’s way of stimulating itself when the baby is sleeping so much. This aids development of the CNS. Babies spend much more time in REM sleep than at any other time of life. The rapid eye movements aid the health of the eye, circulating moisture and oxygenating the eye. Non-rapid eye-movement sleep (NREM) is almost motionless sleep with deep, slow brain waves and slowed heart rate. o Crying is the baby’s only communication method at birth, yet it is very effective in stimulating the responses of others. Everyone is bothered by a crying baby, whether it is yours or not. Parents come to recognize and discriminate their baby’s cry from others. Most cries are to alert to physical needs, hunger, temperature changes, noise, pain, discomfort. Babies will also emit an empathy cry when they hear other babies crying! We are born with the potential for empathy for others, but life and abuse can obliterate it over time. o Soothing Pick up, rock or walk baby. Swaddle the baby in a blanket or hold him close to your body. Offer a pacifier. Stroll or car ride. Massage. Make rhythmic sounds. (Ssh, ssh, sh!) Let baby cry for short periods to recover your nerves. o Abnormal crying is seen in brain-damaged babies. This cry is shrill and piercing and often triggers negative responses in caregivers. This is another reason these babies are often abused. o Colic is a persistent crying that often occurs late in the afternoon, perhaps due to poor brain regulation of arousal cycles, or poor digestion. Sensory capacities Touch stimulates physical development, but also emotional development. Babies are very sensitive to touch and they do feel pain. Now we give local anesthetics to babies being circumcised, but in the past it was thought they didn’t feel much, so they didn’t use anesthetic. Without relief from pain, babies develop a heightened reaction to pain or distress. Taste and s mell – babies like sweet tastes (breast milk is very sweet) and they turn up their nose and react to bitter tastes. Taste preferences may be shaped by the diet of the mother. Odor preferences are innate and they show a preference for mother’s smell. Hearing is developed before birth, as babies react to loud noises by jumping in the womb. They prefer complex sounds, voices, etc. They can discriminate the distinct sounds of all the languages of the world, but quickly come to respond to the sounds of the native language and lose discrimination of other sounds. Because babies respond better to more high-pitched sounds, adults take on a certain “baby language” which is sing song and rises at the end of the sentence. Vision is least developed at birth so visual acuity (fine discrimination) is limited, but babies can see about 8 in. away and can track moving objects. Color vision is limited, so many newborn mobiles are in black and white. Neonatal Behavioral Assessment Scale examines the baby’s reflexes, arousal states, responsiveness to environmental stimuli. Asian and Native-American babies seem to be less irritable than Caucasian babies, possibly because mothers in those groups respond with soothing and nursing more quickly, carrying their babies in wraps about their bodies, which is soothing and stimulating to a baby. Changes in scores in the first weeks reflect parenting practices and recovery from stress of birth.