Birth & Lactation
• uterine contractions are caused by a drop in
progesterone level.
• it is thought that there may be a chemical
released by the fetus (a lung protein, signaling
that the baby is developed enough to breathe
outside the uterus) that causes a drop in
progesterone
• uterine contractions occur, due to the drop in
progesterone, and this has a positive feedback
effect on the secretion of oxytocin (by the
posterior pituitary), signaling the beginning of
labor.
• oxytocin release is a positive feedback cycle;
emotional and physical stress due to uterine
contractions cause the release of more oxytocin.
• false labor (Braxton Hicks contractions) can
occur through the third trimester and near the
beginning of labor when progesterone levels are
initially dropping.
• the hormone relaxin, produced by the
placenta, is secreted prior to labor to help
loosen the pelvic ligaments.
• the mother’s cervix becomes thin and begins
to dilate as the baby’s head pushes on it.
• the amniotic membrane bursts and amniotic
fluid lubricates the canal.
(Water breaking)
• as the baby progresses through the birth
canal, contractions become stronger and more
frequent, until the baby is born
• labor can last from 2-24+ hours
• umbilical cord is clamped and cut
• APGAR score
• after the baby is born, the placenta detaches
from the uterus wall and is expelled from the
birth canal (often called the “after birth”)
•it is important that the entire placenta detaches
so that there are no “open wounds” in the
uterus or the woman may bleed to death. The
placenta is checked by a doctor to ensure that
the entire placenta has detached
during pregnancy, estrogen and progesterone
levels help prepare the breast for milk production.
•
each breast contains around 20 lobes of glandular
tissue, each with a duct which carries milk to the
nipple.
•
Expulsion of the placenta causes the hormone
prolactin to be released by the anterior pituitary.
Prolactin stimulates the glands within the breast
to produce milk.
•
Prolactin increases during pregnancy but milk
production is suppressed by high levels of
estrogen & progesterone from the placenta.
(Prolactin is inhibited.)
•
During delivery  placenta removed 
decreased estrogen & progesterone  increased
milk production
•
• The first milk is a few drops of clear fluid called
colostrum. This is rich in antibodies to give
temporary immunity. When prolactin levels
increase after the birth of a child, this stimulates
the addition of milk fat to the breast milk.
• Breast milk does not flow easily. The suckling
action of a newborn stimulates the nerves endings
in the areola (dark part) of the breast. This
causes the release of oxytocin from the posterior
pituitary
• oxytocin causes weak contractions of the
glands in the breast, helping the milk move
towards the nipple. The oxytocin that is released
by the baby breastfeeding also helps the uterus
of a mother to return to its original shape and
size because it causes the uterus to contract
slightly.
• mothers can produce up to 1.5L of milk per day.
Milk Production
= ensure that her diet contains
The mother
must
Milk Flow =
PROLACTIN!! especially calcium, since 2-3g of
many nutrients,
OXYTOCIN!!
calcium and phosphate are released through
breast milk. Breast milk also contains antibodies
to help a child develop immunity.
+
Pregnancy causes
Pituitary gland
Placenta
Prolactin
Milk Production
Estrogen & Progesterone
-
When placenta is removed during delivery, the inhibitory effect
is removed.
3
2
1
+
+
nipple receptors  oxytocin  milk release
Infertility
• Males
• Low sperm count
• Hot tubs and tight clothing
• Blockage
• Retrograde ejaculation
• Sperm is blocked and will move into the bladder
• Psychological
• Stress, fear, guilt, nervousness
Infertility
• Females
• May not produce gametes
• Obstructions
• Lack of ovulation
• Diet, stress, rigorous physical exercise, menopause, breastfeeding
• Contraceptives
Contraceptives
• Aka birth control
• Condoms
• Diaphragms
• Inserted and cover the vagina; used with a spermicide
• Intrauterine devices (IUD)
• Prevents implantation
• Pill
• Stimulated pregnancy and prohibits ovulation
Technologies associated with pregnancy
1) In vitro fertilization (IVF)
1) involves removing eggs from
the ovaries, 2) fertilizing them in
the laboratory and then replacing
the embryos 3) into the uterus
where they implant and mature.
They successfully delivered Louise
Brown in 1978, the world's first
test tube baby.
-- Various hormone medications are administered in the treatment cycle.
Their purpose is to:
i) Enhance the growth and maturation of several follicles, thereby improving
chances for fertilization
ii) Control the timing of ovulation so eggs can be retrieved before they are
spontaneously released
Multiple pregnancies are the most common
complication occurring in about 20% of IVF
cases, since more that one embryo is usually
implanted .
-
2) Fertility drugs
 used to stimulate follicle production in men
and/or women. It increases the number of
eggs or sperm produced. Often used prior to
IVF to stimulate egg development.
3) Amniocentesis
 a small amount of amniotic fluid is drawn
from the mother’s uterus (using a long needle,
going through the woman’s belly). This fluid is
genetically tested for disorders (usually
chromosomal). Can be preformed in weeks 1518 of pregnancy. There is a chance of
miscarriage with this procedure.
4) Chorionic Villus Sampling (CVS)
 similar to amniocentesis.
The needle draws out
placental cells rather than
amniotic fluid. This test can
be preformed as early as 10
weeks, but also carries the
risk of miscarriage. Unlike
amniocentesis, CVS is
unable to test for neural
tube defects.
5) Ultrasound
 technique that uses sound waves to study and
treat hard-to-reach body areas. In scanning with
ultrasound, high-frequency sound waves are
transmitted to the area of interest and the returning
echoes recorded by a sonograph, which produces an
image.
6) Artificial Insemination
 occurs when live sperm are inserted into ovulating female through a
syringe with the hope that fertilization will occur.
7) Stem Cells from umbilical cords
 stem cells are primitive cells that give rise to
other types of cells.
 These cells are undifferentiated and contain
all of the genetic information needed to create
all of the cells in the body.
These cells are less prone to rejection (unlike
bone marrow stem cells) because they lack the
features that would allow them to be
recognized by the recipient’s immune system.

 Stem cells can be used to help treat diseases
such as leukemia, lymphoma and anemia.
Doctors and scientists can take stems cells and
direct them to create different cell lines such as
neural tissue, liver cells, blood cells… etc. Cord
Blood Banking.
8) AFP - alpha-fetoprotein test
 a blood test done on pregnant mother.
a. Low levels of this protein may
indicate Down Syndrome.
b. High levels may indicate neural tube
disorders.
ie. Spina
bifida.
9) RH incompatibility test and treatment
a. RH negative women carrying RH positive
baby is a problem.
b. First pregnancy leads to mother producing
antibodies against RH antigens during birth
(Blood mixes...).
c. Second pregnancy will see antibodies from
mom cross the placenta and harm fetal blood
cells causing anemia and even death.
d. RH -ve women now given anti RH serum
(RHoGAM) after first birth to destroy antigens
and prevent formation of antibodies.
10) Genetic Counseling
 go to counseling to discuss risks of child being born with an
abnormality/disease.
Pregnancy Problems
1.) Ectopic pregnancy
- occurs when the developing zygote implants in the fallopian tubes, rather
than the endometrium. The embryo develops there and this causes great
risk to both the mother and the baby, and usually cannot be saved.
2.) Breech birth
At the time of delivery the fetal buttocks are the
presenting part in the maternal pelvis.
-
- Frank breech - the fetal hips are flexed and the
knees extended with the feet near the shoulders,
accounting for 60-65% of breech presentations at
term
-Incomplete breech - one or both of the fetal hips
are incompletely flexed, resulting in some part of
the fetal lower extremity as the presenting part.
Thus the terms single footling, double footling, knee
presentation. Accounts for 25-35% of breech
presentations.
- Complete breech - similar to frank breech except
one or both knees are flexed rather than extended.
Accounts for 5% of breech presentations.
- The doctor may attempt to shift its position by
applying pressure to the abdominal wall and
manipulating the fetus in an attempt to turn it.
This process is called an external cephalic version
(ECV). In some cases, babies are delivered
breech. Recent studies have shown that heat
acupuncture treatments can be used on the
woman’s feet in order to stimulate the baby to
turn into the right position for delivery. In cases
where delivery cannot be preformed, and the
baby does not turn over, a caesarian section is
preformed.
3.) Placenta Previa
– when placenta lies low in the uterus. Painless vaginal bleeding is a sign.
Diagnosed by ultrasound. Baby should not be delivered vaginally if the
placenta previa persists at term.
4.) Caesarian section (c-section)
- In this procedure, a doctor makes an incision in
a woman's abdomen and uterus and removes her
baby through it.