Definition by wanghonghx

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									              Definition
• Contraception (birth control) prevents
 pregnancy by interfering with the
 normal process of ovulation,
 fertilization, and implantation.
 There are different kinds of birth
 control that act at different points
 in the process.
                     Purpose
• Every month, a woman's body begins the process
  that can potentially lead to pregnancy. An egg
  (ovum) matures, the mucus that is secreted by the
  cervix (a cylindrical-shaped organ at the lower end of
  the uterus) changes to be more inviting to sperm,
  and the lining of the uterus grows in preparation for
  receiving a fertilized egg. Any woman who wants to
  prevent pregnancy must use a reliable form of birth
  control.
• Birth control (contraception) is designed to interfere
  with the normal process and prevent the pregnancy
  that could result. There are different kinds of birth
  control that act at different points in the process,
  from ovulation, through fertilization, to implantation.
  Each method has its own side effects and risks.
  Some methods are more reliable than others.
 History of birth control techniques

• Ancient Egypt and Rome
• about 1850 BC. It describes various
  contraceptive pessaries, including acacia gum,
  which recent research has confirmed to have
  spermatocidal qualities and is still used in
  contraceptive jellies. Other birth control methods
  mentioned in the papyrus include the application
  of gummy substances to cover the "mouth of the
  womb", a mixture of honey and sodium
  carbonate applied to the inside of the vagina
 History of birth control techniques
• Ancient China
• In the same century Sun Ssu-mo
  documented the "thousand of gold
  contraceptive prescription" for women who
  no longer want to bear children. Made of
  oil and quicksilver heated together for one
  day and taken orally the prescription
  induced sterility
 History of birth control techniques
• Early Islam
• In the late ninth to early tenth century the Persian
  physician Muhammad ibn Zakariya al-Razi
  documents coitus interruptus, preventing ejaculation
  and the use of suppositories to block the cervix as
  birth control methods. He describes a number of
  suppositories, including elephant dung, cabbages
  and pitch, used alone or in combination. During the
  same period Ali ibn Abbas al-Majusi documents the
  use of suppositories made of rock salt for women for
  whom pregnancy may be dangerous. In the early
  tenth century Abu Ali al-Hussain ibn Abdallah ibn
  Sina, known in Europe as Avicenna, included a
  chapter on birth control in his medical
  encyclopaedia The Canon of Medicine, documenting
  20 different methods .
              Methods
• There are more different types of birth
  control available today than ever. They
  can be divided into a few groups based
  on how they work. These groups
  include:
• 1- Physical methods
• 2-Behavioral methods
Methods
• Physical methods
• Hormonal methods
  – Barrier methods
  – Ormeloxifene (Centchroman)
  – Emergency contraception
  – Intrauterine methods
  – Sterilization
          Physical methods
          Hormonal methods
• Female hormonal contraception
• There are various delivery methods for
  hormonal contraception. Forms of
  synthetic oestrogens and progestins
  (synthetic progestogens) combinations
  commonly used include the combined oral
  contraceptive pill ("The Pill"), the Patch,
  and the contraceptive vaginal ring
  ("NuvaRing"). A monthly injectable form.
               Physical methods
               Hormonal methods
• Other methods contain only a progestin (a
  synthetic progestogen). These include the
  progesterone-only pill (the POP or 'minipill'), the
  injectables Depo Provera (a depot formulation of
  medroxyprogesterone acetate given as an
  intramuscular injection every three months) and
  Noristerat (Norethindrone acetate given as an
  intramuscular injection every 8 weeks), and
  contraceptive implants. The progestin-only pill
  must be taken at more precisely remembered
  times each day than combined pills.
  How Hormonal Methods Work

• Hormonal contraceptives prevent ovulation. No
  egg is released so sperm cannot fertilize it. It is
  widely agreed that this is a major mechanism of
  hormonal birth control.
• A woman may ovulate anyway. Hormonal
  contraceptives may also prevent fertilization by
  changing the consistency of natural secretions in
  the vagina, making it harder for the sperm to
  reach the egg. It is not clear how effective this
  mechanism is in preventing fertilization
How Hormonal Methods Work
A woman may ovulate anyway, and sperm may •
still reach the egg, resulting in fertilization. When
this occurs, hormonal contraceptives make it
in the uterus by implant difficult for the embryo to
keeping the edometrium (lining of the uterus)
thinned. This results in the death and expulsion
of the embryo. Most scientists agree this occurs,
Some doctors do .but it is not clear how often
because not prescribe hormonal contraceptives
.they find this mechanism objectionable
              Physical methods
              Hormonal methods
Mechanism of Action and Efficacy •
1-PILLS: •

Progestin-only pills contain one of the synthetic •
progestins (levonorgestrel, norethindrone, norgestrel,
lynestrenol, desogestrel, or ethynodiol diacetate) in small
amounts to prevent conception through a combination of
mechanisms: ovulation suppression in some cycles,
thickening of cervical mucus to prevent sperm
penetration, atrophy of the endometrium (shrinking of the
lining of the uterus), and altered tubal function. The
amount of progestin in progestin-only pills is about 25%
of that in combined (estrogen and progestin) oral
contraceptive pills.
            Physical methods
            Hormonal methods
Progestin-only pills must be taken at the same •
time each day to be effective. The hormone is
eliminated within 24 hours, at which time the
cervical mucus regains its normal permeability to
sperm. As a result, progestin-only pills typically
have higher failure rates than combined oral
contraceptives. With perfect use, the first-year
probability of pregnancy is 0.5%. With typical
use, the failure rate is 8%, varying according to
age
How take???
Most combination pills come in either a 21-day •
pack or a 28-day pack. One hormone pill is
taken each day at about the same time for 21
days. Depending on your pack, you will either
stop taking birth control pills for 7 days (as in the
21-day pack) or you will take a pill that contains
no hormones for 7 days (the 28-day pack). A
woman has her period when she stops taking
the pills that contain hormones. Some women
prefer the 28-day pack because it helps them
.stay in the habit of taking a pill every day
Physical methods
Hormonal methods
           Physical methods
           Hormonal methods
2- Depot •
Depot medroxyprogesterone acetate is given as •
a 1 milliliter (150 mg of microcrystals), deep
intramuscular injection every 12 weeks. Because
DMPA is not a sustained-release system, its
action relies on obtaining high levels of progestin
which decline over three months, but can remain
above a contraceptive concentration for n the
first year of use in the United States is 0.3% with
          Physical methods
          Hormonal methods
perfect use and three percent in the first •
year with typical use because some
women do not return for their injections
from a nurse or physician every three
months as required for maximum efficacy
many additional weeks.
Physical methods
Hormonal methods
    3- A contraceptive implant •
            Physical methods
            Hormonal methods
containing 68 mg of the progestin etonogestrel •
in a single rod made of ethylene vinyl acetate
(EVA) was approved for use in the United States
in July, 2006, is initially absorbed by the body at
a rate of 60 micrograms (mcg) per day which
slowly declines to 30 mcg per day after two
years of use. The ENG implant can be removed
at any time at the woman’s discretion, but will
remain effective for at least three years
compared to the seven years efficacy of
Norplant
             Physical methods
             Hormonal methods
Progestin-containing implants have two primary •
mechanisms of action: inhibition of ovulation and
restriction of sperm penetration through cervical mucus
implant (Implanon) suppresses ovulation by controlling
hormones in the pituitary and hypothalamus glands
which is required to support the production, growth, and
maturation of eggs in the ovary. Progestins affect the
cervical mucus, making it viscous and scanty so that
sperm cannot enter the uterus and reach the egg to
fertilize it .
No signs of embryonic development have been found •
among implant users.
How is the contraceptive implant
       put under the skin
  •
.It is put in the inner side of the upper arm •
It is usually first inserted within five days of a •
period starting. (This ensures that you are not
.pregnant.) It is effective from then on
An injection of local anaesthetic is used to numb •
the skin. A small cut is made and the implant
placed under the skin. The wound is dressed
.and will soon heal just like any other small cut
The area around the implant may be bruised •
.and sore for a few days, but this soon goes
Physical methods
Hormonal methods
          Physical methods
          Hormonal methods
• Combined Contraceptive Vaginal Ring
• vaginal ring is a flexible, transparent ring
  54 mm in diameter, made of ethylene vinyl
  acetate (EVA) copolymer plastic. The user
  places and removes the ring herself; there
  is no “wrong” way to insert it as long as it
  touches the vaginal lining. Each ring is
  designed for one cycle of use,
          Physical methods
          Hormonal methods
, which is three weeks of continuous ring •
use followed by one week without the ring
to provoke a scheduled withdrawal bleed.
The ring releases 120 mcg of etonogestrel
(the active metabolite of desogestrel) and
15 mcg of ethinyl estradiol per day.
Physical methods
Hormonal methods
         Physical methods
         Hormonal methods
• Transdermal Contraceptive System (THE
  PATCH
           Physical methods
           Hormonal methods
The transdermal contraceptive system is a 4.5- •
cm square patch that provides continuous
circulatory levels of norelgestromin (the active
metabolite of norgestimate) and ethinyl estradiol
equivalent to 150 mcg of norelgestromin and 20
mcg of ethinyl estradiol per day. It is usually
placed on the hip or abdomen and should not be
applied to the breasts. The total amount
(measured by AUC) of the hormonal
concentrations achieved by the patch is greater
than with typical OCs
          Physical methods
          Hormonal methods
. One patch is applied weekly for three •
consecutive weeks, followed by one week
without its use to allow for a scheduled
withdrawal bleed
The first-year pregnancy rate for perfect •
use is 0.3%
Patches maintain adhesiveness for a week •
regardless of heat, moisture, activity levels
          Physical methods
          Hormonal methods
Benefits        •
The non-contraceptive benefits of progestin- •
only methods include decreases in
menstrual blood loss, anemia, menstrual
cramping, ovulatory pain, and pain with
endometriosis (abnormal growth of the
tissue that lines the uterus), as well as
decreased risks of endometrial and ovarian
cancer. Progestin-only methods may be
safely used while breastfeeding.
Physical methods
Hormonal methods
Disadvantages and Side Effects •
Hormonal methods do not protect against •
sexually transmitted diseases (STDs) and
human immunodeficiency virus (HIV),
although they may provide some protection
against pelvic inflammatory disease (PID) by
thickening cervical mucus, which is also an
important factor in their contraceptive action
           Physical methods
           Hormonal methods
Menstrual disturbances are the main reason •
why women discontinue progestin-only
contraception, but women may also
experience systemic side effects, such as
breast tenderness, acne, and mood changes,
including depression. Some of the less
common systemic side effects of implants
and injections, such as acne and unwanted
hair growth or loss, are associated with the
decrease in levels of sex hormone-binding
globulin caused by decreased ovarian
production of estradiol
         Physical methods
         Hormonal methods
Weight gain is a common reason for •
discontinuing hormonal
contraceptives, but only the injectable
DMPA (DepoProvera) has been clearly
associated with increasing weight, and
then only in young women who were
already overweight when they initiated
use.
             Physical methods
             Hormonal methods
current breast cancer. Use of a progestin-only •
method is generally NOT recommended for women
who have had breast cancer treated without
recurrence for less than five years, active hepatitis,
severe cirrhosis, benign or malignant liver tumors,
current deep vein thrombosis (blood clots), or
pulmonary embolism (blood clot in the lung).
Discontinuing progestin-only methods should be
considered by who anyone who develops migraines
with focal neurologic symptoms, ischemic heart
disease, or stroke .
              S.E
hair growth         acne
   Male hormonal cotraceptive
Commonly known as the “male pill” •
contained Testosterone , a
hormonal contraceptive for men
will probably not be delivered as a
pill. Researchers are coming
closer to a marketable male
hormonal contraceptive (MHC)
delivered by injection or implant,
but there is nothing commercially
.available right now
   Male hormonal cotraceptive
?How would it work •
Male hormonal contraceptives attempt to block •
or severely reduce the production of sperm.
They accomplish this by stopping the secretion
of a man's reproductive hormones in the brain
and testes. When levels of testosterone in the
testes are low, sperm production slows or halts.
Typical MHC formulations provide replacement
testosterone to the man’s bloodstream to
maintain male characteristics like muscle mass
and facial hair.
   Male hormonal cotraceptive
?How long would it take •
The fastest possible onset of efficacy that •
a man taking an MHC could hope for
would be 1½ - 2½ months. Once
spermatogenesis is halted, it takes an
average of 2½ months for the last
spermatids produced to travel through and
exit the epididymis.
Male hormonal cotraceptive
?What side effects would be expected •
weight gain, increased acne and changes in mood. •
.These side effects are.
A more serious side effect of altering a man's androgen •
metabolism is a depressed level of high-density
lipoprotein cholesterol (HDL-C) in the blood. HDL-C is a
healthy type of cholesterol which has been correlated
with reduced risk of atherosclerosis (hardening of the
arteries). Volunteers in clinical trials of certain types of
synthetic androgen experience a 15% drop in HDL-C
levels. If this side effect can not be mitigated, men with a
risk of heart disease should be advised to avoid MHCs
Researchers were originally concerned that high levels •
of androgen might over-stimulate the prostate gland
 Physical methods
Intrauterine methods
           Physical methods
          Intrauterine methods
An intrauterine device. •
These are contraceptive devices that are •
placed inside the uterus. They are usually
shaped like a "T" — the arms of the T help
hold the device in place. There are also
frameless IUDs, which are less likely to
cause complications; an example would be
GyneFix. This brand is hard to find in North
America. There are two main types of
intrauterine contraceptives:
            Physical methods
           Intrauterine methods
1-those that contain copper (which has a spermicidal •
effect),
The copper device is approved for 10 years of use •
but has been shown to be effective for at least 12
years. After prolonged continuous use, the
cumulative pregnancy rate is 1.6 percent at seven
years, and 2.2 percent at 8 and 12 years. Overall, the
failure rate is substantially less than one per 100
women per year, except in women under age 25 who
experience a slightly higher failure rate, most likely
because they are more fertile than older women
         Physical methods
        Intrauterine methods
Mechanism of Action and Efficacy •
he copper IUD releases free copper and •
copper salts that have both a
biochemical and morphologic impact
on the uterine lining (endometrium) and
produce alterations in cervical mucus
and secretions which also have
spermicidal effects.
           Physical methods
          Intrauterine methods
Advantages and Noncontraceptive Benefits •
Women who cannot use hormonal methods can •
use copper IUCs. There is rapid return to fertility
and no increased risk of infertility after IUC
removalThe copper device is associated with a
decreased risk of endometrial cancer, and no
increased risk, and possibly a decreased risk, of
cervical cancer
         Physical methods
        Intrauterine methods
Disadvantages and Side Effects •
The copper IUC may increase menstrual •
blood loss, cramping, intermenstrual
spotting, and vaginal discharge. Heavy
menses and dysmenorrhea
            Physical methods
           Intrauterine methods
2- and those that release a progestin (a synthetic •
progestogen).
The levonorgestrel system is approved for up to five •
years of use in the United States but has been
shown to be effective up to seven years
Mechanism of Action and Efficacy •
the progestin released by hormonal IUCs shrinks the •
glandula structures in the uterine lining and thickens
cervical mucus so that sperm cannot penetrate it (1,
48). The levonorgestrel system also produces serum
concentrations of progestin that lead to partial
inhibition of ovarian egg development and ovulation.
          Physical methods
         Intrauterine methods
Advantages and Noncontraceptive Benefits •
more effective than oral progestins •
In women who sometimes fail to ovulate and •
in perimenopausal and postmenopausal
women taking estrogen, the levonorgestrel
IUC can be used to protect the uterine lining
from the effects of estrogen by preventing
the overgrowth that can lead to cancer of the
uterus
          Physical methods
         Intrauterine methods
Disadvantages and Side Effects •
may cause irregular bleeding and spotting in •
the first several months of use This side
effect is experienced by 30% of women after
two years of use Complaints of menstrual
problems, including amenorrhea, missing
periods, and spotting decline after one year
and are less common among patients older
than 30 Hormonal side effects (including
headache and skin and hair changes)
 Physical methods
Intrauterine methods
             Physical methods
               Ormeloxifene
Ormeloxifene (Centchroman) •
Ormeloxifene (Centchroman) is a selective •
estrogen receptor modulator, or SERM. It
causes ovulation to occur asynchronously with
the formation of the uterine lining, preventing
implantation of a zygote. It has been widely
available as a birth control method in India since
the early 1990s, marketed under the trade name
Saheli. Centchroman is legally available only in
India
Physical methods
  Ormeloxifene
       Physical methods
     Emergency contraception
Some combined pills and POPs may be •
taken in high doses to prevent
pregnancy after a birth control failure
(such as a condom breaking) or after
unprotected sex. Hormonal emergency
contraception is also known as the
"morning after pill," although it is
licensed for use up to three days after
intercourse.
        Physical methods
      Emergency contraception
Copper intrauterine devices may also be •
used as emergency contraception. For this
use, they must be inserted within five days of
the birth control failure or unprotected
intercourse.
Emergency contraception appears to work •
by suppressing ovulation. However, because
it might prevent a fertilized egg from
implanting some people consider it a form of
abortion. The details of the possible methods
of action are still being studied.
             Physical methods
                Sterilization
              for male& femle
Surgical sterilization is available in the form of •
tubal ligation for women and vasectomy for men.
Sterilization should be considered permanent. In
women, the process may be referred to as "tying
the tubes," but the Fallopian tubes may be tied,
cut, clamped, or blocked. This serves to prevent
sperm from joining the unfertilized egg. The non-
surgical sterilization procedure, Essure, is an
example of a procedure that blocks the tubes,
wherein micro-inserts are placed into the
fallopian tubes by a catheter passed from the
vagina through the cervix and uterus.
           Physical methods
             Sterilization
Although sterilization should be •
considered a permanent procedure, it is
possible to attempt a tubal ligation reversal
to reconnect the Fallopian tubes in
females, or a vasovasostomy by which
vasectomies are reversed in males. The
rate of success depends on the type of
sterilization that was originally performed
and damage done to the tubes as well as
the patient's age
           Physical methods
            Barrier methods
Condom (rolled-up). •
Barrier methods place a physical •
impediment to the movement of sperm
into the female reproductive tract.
The most popular barrier method is the •
male condom, a latex or polyurethane
sheath placed over the penis. The condom
is also available in a female version, which
is made of polyurethane.
          Physical methods
           Barrier methods
The female condom has a flexible ring •
at each end — one secures behind the
pubic bone to hold the condom in
place, while the other ring stays
outside the vagina.
Cervical barriers are devices that are •
contained completely within the vagina.
             Physical methods
              Barrier methods
The contraceptive sponge has a depression to hold •
it in place over the cervix. The cervical cap is the
smallest cervical barrier. Depending on the type of
cap, it stays in place by suction to the cervix or to
the vaginal walls. The diaphragm fits into place
behind the woman's pubic bone and has a firm but
flexible ring, which helps it press against the vaginal
walls.
Spermicide may be placed in the vagina before •
intercourse and creates a chemical barrier.
Spermicide may be used alone, or in combination
with a physical barrie
Physical methods
 Barrier methods
Physical methods
 Barrier methods
        Behavioral methods

Behavioral methods involve regulating •
the timing or methods of intercourse to
prevent the introduction of sperm into
the female reproductive tract, either
altogether or when an egg may be
present.
         Behavioral methods
Fertility awareness •
Symptoms-based methods of fertility •
awareness involve a woman's observation
and charting of her body's fertility signs, to
determine the fertile and infertile phases of
her cycle.
        Behavioral methods
Coitus interruptus •
also known as the withdrawal or pull-out •
method, is the practice of ending sexual
intercourse ("pulling out") before
ejaculation.
Lactational •
From ancient times women tried to extend •
breastfeeding in order to avoid a new
pregnancy.

								
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