The Wonders of Pregnancy Chapter 8 Family and Consumer Science Department Mrs. Karen Swope

Pregnancy- the condition of carrying a developing child in the uterus. Conception occurs when sperm and egg unite Sperm and egg each contain 23 chromosomes The new cell now contains 46 chromosomes and is called a zygote (germinal stage) Zygote travels through the fallopian tube and attaches to the uterine wall, takes 2 wks.

Pregnancy: Gender Determination The egg has 1 X chromosome. Half the sperm have an X chromosome, half have a Y chromosome. If an X chromosome enters the egg the baby will be a girl. If a Y enters the baby will be a boy.

Early cell division - 30 hours The zygote is now called a blastocyst, (ball of cells) Still part of the germinal stage. The germinal stage lasts approx. 2 weeks. When the blastocyst attaches to the uterine wall it becomes an embryo. (2wks-8wks)

Signs of Pregnancy Missed menstrual cycle, or spotting Hormonal changes cause the woman to be very tired Nausea (may occur at any time, not just in the morning) Breasts become tender, may feel fuller Frequent urination

Pregnancy tests Performed in a medical office, health clinic - most accurate; may use urine or blood test Home tests - fairly accurate, greater chance of error, best if done 1 week after missed period Test detects HCG (Human Chorionic Gonadotropin) hormone in woman’s urine. Take note of expiration date on package

Physical exam: 6-8 wks into pregnancy a pelvic exam should be done uterus increases in size, cervix softens A thorough health history is done Delivery date is predicted

Prenatal Support Systems Amniotic sac- membrane that surrounds and protects Amniotic fluid- fluid in sac that cushions and protects

Prenatal support systems Placenta - organ in which the mother’s blood vessels meet the baby’s capillaries. Umbilical cord- cord of blood vessels that connects the placenta to the baby

Embryo Stage Begins at implantation in uterine wall through the end of 2nd month Development is rapid Foundations for brain, spinal cord, nervous system, eyes form

Embryo Stage Heart is pumping By 8 weeks all internal organs are developing Mother’s diet and environment can have a great affect on embryo’s development Embryo is about 1/2 inch long

The Fetal Stage 3rd month Beginning of the 3rd month Eyelids form Movement begins Genitals have appeared

The Fetal Stage 4th month Rapid growth 6 inches, 4-7 ounces Skin is thin and transparent Mother notices movement Lanugo appears- downy hair over fetus’s body

The Fetal Stage 4th month

The Fetal Stage 5th month About 12 inches long 8oz. - 16 oz. Vernix appears - white, pasty substance that coats and protects the fetus’s skin

The Fetal Stage 6th month 9-14 inches long 1 1/2 pounds Lungs and digestive system are still developing If born at 22-24 wks, has a very slim chance of survival

The Fetal Stage 7th month About 15 inches 2-3 pounds Little fat under skin’s surface Fair chance of survival is born prematurely

The Fetal Stage 8th month 16-17 inches long About 4 pounds Refinement of internal organs Fetus may hiccup

The Fetal Stage 9th month 38-40 weeks is considered full term 6-9 pounds 17-22 inches long Lanugo and vernix are almost gone Lightening - baby shifts head down, ready for birth Placenta releases oxytocin, starts labor

Summary Pregnancy begins when egg and sperm unite. Prenatal development occurs between conception and birth. Pregnancy is divided into three stages, according to the baby’s development. During the 9 months f pregnancy a woman’s body changes to accommodate the growing baby.

Summary cont. Several complications may occur. A woman should be familiar with these complications and watch for warning signs. Emotional changes may occur. Sharing emotions and the pregnancy experience may strengthen the couple’s relationship.