Inadequate Prenatal Care

Inadequate, absent, or delayed prenatal care can allow maternal nutritional deficiencies to deprive a fetus of needed nutrients. Chronic diseases, such as hypertension or diabetes, increase the risk of fetal damage. Without prenatal care, a woman is three times more likely to give birth to a low-birth-weight baby—one who will be 40 times more likely to die during the first 4 weeks of life than a normal-birth-weight infant. (The ideal time to start prenatal care is before conception.) Still, about 20% of women ii the United States receive no prenatal care in the first trimester—a critical time to change habits.

Lifestyle Factors

Smoking, alcohol consumption, use of some medications, and illegal drug use (such as cocaine and marijuana) in pregnancy all lead to harmful effects. The Nutrition Issue at the end of this article reviews one effect of alcohol—fetal alcohol syndrome. The nicotine in cigarette smoke constricts blood vessels and is linked to preterm birth and low birth weight. Smoking also appears to increase the risk of birth defects, sudden infant death, and childhood cancer. Problem drugs include aspirin (when used heavily), hormone ointments, nose drops, rectal suppositories, and medications prescribed for previous illnesses. One goal of Healthy People 2010 is 100% abstinence from alcohol, cigarettes, and illicit drugs by pregnant women.

Prenatal Ketosis

Ketosis is not desirable for the growing fetus. Ketone bodies are thought to be poorly used by the fetal brain, implying possible slowing of fetal brain development. Researchers oppose crash diets or fasting for more than 12 hours during pregnancy. A pregnant woman can develop significant ketosis after only 20 hours of fasting. Eating about 100 grams of carbohydrate every day prevents ketosis. Even nonpregnant women usually eat twice this amount.