Pregnancy and Parenthood Pregnancy and Childbirth April 4, 2011

Vocabulary 1. Gametes [Sperm (male) and egg (female)] Each gamete only has half the DNA needed to create a new human being 2. Fertilized egg/zygote Zygote = the first cell of a new person, formed at fertilization 3. Blastocyst Blastocyst = a hollow ball of cells that attaches to the uterine wall 4. Embryo Embryo = the developing infant during the first two months of conception

Becoming pregnant A woman can become pregnant from sexual intercourse with a man  It takes TWO PEOPLE to become pregnant The male gamete (sperm) travels through the fallopian tubes of the woman, where it meets a female gamete (egg) and fertilizes it.  Each gamete contains half the DNA necessary for a new human being.  After hours, the two gametes will combine (the sperm enters the egg, fertilizing it). Once the egg is fertilized, it is called a zygote.  A zygote contains all the DNA necessary for a new human being.

After fertilization After being fertilized, the zygote begins to replicate…  From 1 to 2 cells (a day and a half)  From 2 to 4 cells (two days)  From 4 to 8 cells (two and a half days)  From 8 to 16 to 32 cells (three days) By the fourth day after fertilization, the zygote becomes a hollow ball of cells called a blastocyst. On the 6-7 th day, the blastocyst attached to the uterine wall By the th day, the blastocyst is called an embryo, and has implanted itself into the uterus.  Now, we say the woman has become pregnant.

After fertilization

Very early pregnancy Once the embryo is implanted into the uterus, it starts to change things…  Secretes a hormone called HCG into the mother’s blood.  This hormone stops the menstrual cycle and allows the pregnancy to continue by increasing the levels of estrogen and progesterone.  HCG also causes nausea and vomiting (morning sickness), enlarged breasts, more frequent urination, fatigue, and growth of the uterus.  If a woman uses a “home pregnancy test”, it is looking for HCG in her urine.

Dangers of early pregnancy Early pregnancy is usually a very safe time – many women do not even realize they have become pregnant. Rarely, however, the embryo may implant in the wrong place – outside of the uterus. Usually this occurs when the embryo implants on the fallopian tube, and is called a tubal pregnancy.  If this happens, the embryo will soon become too large for the space, and the tube will burst.  This causes internal bleeding and requires immediate medical help.  Seeing a doctor when you become pregnant can make sure that your pregnancy is normal and healthy.

Development of the fetus Fetus is the the infant during pregnancy. The body of the fetus is usually formed completely by ten weeks.  During the rest of the pregnancy, the fetus grows larger, and develops functioning organs. Before birth, the fetus receives energy and nutrients from the mother through the placenta and umbilical cord. By birth, the fetus usually weighs around seven pounds.

Development of the fetus – how?? The fetus lives within a fluid-filled sac called the amnion  The fluid is called amniotic fluid.  The fluid protects the fetus from the other parts of the mother’s body, and is a cushion.  When a woman’s “water breaks”, just before birth, this is the fluid that is released. o Within the uterus, an organ called the placenta develops during pregnancy. This secretes hormones to direct pregnancy, and transfers things between mother and fetus Mother  fetus (oxygen, nutrients, energy) Fetus  mother (carbon dioxide, waste)

What happens to the mother? There are obvious and hidden changes to the mother’s body during pregnancy. Many changes help provide more energy:  Her heart beats faster, she grows more blood cells, and breaths more. Many changes make room for the fetus:  The uterus more than triples in size.  Other organs move out of the way to make room – one of the reasons why a pregnant woman needs the bathroom more often!

Staying healthy during pregnancy Healthy behaviors are especially important during pregnancy because they ensure that the fetus will grow healthily.  Nutrition  Healthy weight gain (28-30 pounds)  Physical activity  Managing stress  Prenatal care

HOMEWORK FOR TUESDAY How can a woman avoid becoming pregnant? What are some steps that can be taken if a woman is not ready to have a baby?  Half-page essay, Due Tuesday  Use your book! And your notes!!

Risks during pregnancy The mother controls what is in the fetus’ environment – what is around the fetus. Health risks taken by the mother during pregnancy often put the fetus at risk:  Drug use – many drugs (legal and illegal) can harm the fetus. A doctor should approve any medicine taken.  Alcohol use  Cigarette use

Drinking alcohol during pregnancy Drinking alcohol while pregnant is very dangerous to the fetus, because the fetus is too small to handle any alcohol in the blood. If alcohol is consumed too much or too often, the fetus may develop fetal alcohol syndrome (FAS).  Causes growth retardation, facial malformations, and nervous system problems (such as mental retardation and behavioral problems).

Smoking cigarettes during pregnancy Smoking during pregnancy increases the risks of almost every problem for the fetus. Smoking reduces the amount of oxygen that reaches the fetus, and exposes the fetus to harmful chemicals. Birth defects and life-long health problems can occur in a fetus when the mother smokes during pregnancy.

Childbirth Childbirth has a lot of cultural tradition  It is most important that a woman feel confident and ready to have a child. Stages of labor – actually giving birth 1. Early labor – the fetus becomes positioned for birth 2. Contractions and dilation of the cervix to about 10 centimeters across 3. Infant descends through the birth canal 4. Delivery of the placenta (afterbirth) Very culture-rich part of childbirth

Complications of pregnancy Ectopic pregnancy  The fetus develops outside of the uterus, such as in a fallopian tube, damaging the mother’s internal organs. Eclampsia  High blood pressure during pregnancy, may cause seizures and other complications. Gestational diabetes  A form of diabetes that may occur during pregnancy  Increases the risk of diabetes later in life for mother and child.

Complications of childbirth Breech birth  The fetus is upside down, and not head-first.  Occurs in 5% of pregnancies. Prolapsed cord  This occurs when the umbilical cord leaves the birth canal before the fetus.  The cord will be pinched by the fetus and oxygen to the fetus will be cut off. Pre-term or post-term birth  Infants born premature need extra care and medical assistance to survive.  Infants born later than 40 weeks may cause the mother medical complications and difficult labor. Hemorrhage  Uncontrollable bleeding following labor.

Alternative birthing methods If natural birth is not occurring as is should, there are other ways of removing the infant from the mother’s body:  Epistiotomy – a doctor will cut from the vagina towards the anus to enlarge the birth opening (many risks and complications)  Cesarean birth – a doctor will surgically remove the baby from an incision in the woman’s abdomen (many risks and a longer healing time for the mother)

After the birth After giving birth, the mother slowly returns to her pre-pregnancy body  Lose the increased fluids and uterine size  Hormones return to normal levels During this transition, some women may experience a form of depression called post- partum depression.  Related to the hormonal changes after birth, and to the life-changes related to having a baby

After the birth Breastfeeding is a very healthy and important activity for new infants and mothers. Immediately after birth, the mother will produce colostrum, which is made before breastmilk and contains:  Important nutrients to keep the new baby healthy  Antibodies to keep the baby safe from infection Breastfeeding also triggers hormones that help the mother return to full health

VOCABULARY YOU SHOULD KNOW FROM THIS LECTURE Gamete Fertilize Zygote Blastocyst Embryo HCG Tubal pregnancy Fetus Amnion Amniotic fluid Placenta Fetal alcohol syndrome Epistiotomy Cesarean section Post-partum depression Colostrum