Chapter 4 Pregnancy and Birth

The Prenatal World The Germinal Period The Embryonic Period First two weeks after fertilization Blastocyst adheres to uterine wall Placenta, umbilical cord, and amniotic sac begin to form The Embryonic Period Lasts from third to eighth week Cellular Differentiation occurs3 layers of cellsskin, nervous system, and organs

The Prenatal World The Fetal Period Third month to birth 3rd month—sex organs appear; nervous system continues to develop 4th-6th months—peak growing time; fetus moves around; sucking, pushing, etc. 7th month—growth slows; viability reached; 8th-9th months—internal organs and senses finish developing

Influences on Prenatal Development Teratogens=any agents causing abnormalities: Chemicals: Drugs, chemicals, certain medications, i.e. thalidomide, DES, and common substances, i.e. alcohol, cigarettes Infectious Diseases: (STORCH)--Syphilis, Toxoplasmosis, Rubella, CMV, Herpes, and AIDS

Influences on Prenatal Development Maternal Influences Maternal Nutrition and Weight Normal weight is best Healthy nutritional habits; Eliminate teratogenic substances from diet Vitamins

Influences on Prenatal Development Maternal Emotions Serious stress or depressions may trigger hormones that can cross the placenta Mood swings considered not dangerous unless prolonged and severe Data is very inconclusive regarding negative affects on the fetus, but may occur

Influences on Prenatal Development Diagnosing Fetal Problems Amniocentesis Alpha-Fetoprotein Test Fetoscopy Chorionic Villi Sampling Ultrasound

The Birth Process Stages in the Birth Process Dilation—cervix dilates to 4 inches in diameter Expulsion—fetus delivered from mother The Afterbirth—Placenta discharged

The Birth Process Birth Complications Forceps Delivery Breech Birth—baby born feet first Cesarean Section—surgical delivery through abdomen Anoxia—lack of oxygen; can cause brain damage, cerebral palsy, or death Rh Factor—incompatibility between child’s and mother’s blood after 1st baby when Rh-negative mom has Rh positive baby

The Birth Process The Special Case of Prematurity=baby born before 37 weeks Causes: maternal infection, multiple births, maternal stress, maternal age (under 17 ys. or over 35 ys.), low socioeconomic status due to poor prenatal care, smoking, alcohol use, maternal medical problems not being controlled adequately