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. The mother must ensure that her diet contains many nutrients, especially calcium, since 2-3g of calcium and phosphate are released through breast milk. Breast milk also contains antibodies to help a child develop immunity.

+ Pregnancy causes Pituitary gland Prolactin Placenta Milk Production Estrogen & Progesterone When placenta is removed during delivery, the inhibitory effect is removed.

1 3 + + nipple receptors  oxytocin  milk release 2

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 15 18 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

term - the fetal hips are flexed and the knees extended with the feet near the shoulders, accounting for 60-65% of breech presentations at

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Incomplete breech

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. - one or both of the fetal hips

- 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.