From conception to delivery, a fetus is at the mercy of its environment. A mother-to-be has more control over her internal chemistry than she might think, and her odds of having a healthy baby will be much improved if she follows these 10 tips.
Take steps even before you're pregnant. If you're considering pregnancy, you should take 400 micrograms of folic acid daily to guard against neural tube defects such as spina bifida. Also ask about vaccination against chickenpox or rubella. These and a few other "live" vaccines cannot be given to pregnant women; the illnesses can cause birth defects if contracted during pregnancy.
Don't delay an OB visit. Early blood tests can catch anemia and infections that can affect the fetus if not dealt with quickly. Possibly correctable problems such as heart abnormalities often can be detected in the coming months through echocardiography and other screening tests.
Write down all meds. Your doctor should review your drugs, vitamins, and supplements. Some of them, such as certain antidepression and seizure medications, can harm your baby's heart and increase your risk of miscarriage.
Don't drink. Binge drinking is particularly dangerous to the fetus; known risks include miscarriage, stillbirth, and mental retardation. It may cause facial deformities such as cleft lip and cleft palate.
Don't smoke. That includes inhaling secondhand smoke. Besides stillbirth and low birth weight, sudden infant death syndrome has been linked to cigarette smoke.
Monitor the scales. Gestational diabetes and premature birth are among the dangers of putting on more than about 25 to 35 pounds, or more than about 15 to 25 pounds for an overweight woman.
Get moving. Exercise can moderate weight gain and may increase the flow of oxygen to the fetus.
Eat smart. New research shows a mother's diet during pregnancy has lifelong implications for her baby. A prenatal diet high in protein or fat has been tied to chronic conditions such as heart disease, obesity, and diabetes. Besides following a generally healthful diet of fresh fruits and vegetables, whole grains, and lean proteins, eating fish twice a week (salmon, sardines, and canned light tuna are mercury safe) will provide omega-3 fatty acids for fetal brain development.
Don't get vitamin-happy. More isn't better—stick to the doses recommended by your obstetrician. Excessive vitamin A, for example, can cause head, heart, brain, and spinal cord defects. You may be told to take an iodine supplement; a new study found that prenatal vitamins often provide far less than the 150-microgram minimum recommended for proper nervous-system development.
Check around the house. Certain chemicals, among them BPA and pthalates in plastics, canned-food linings, and cosmetics, mimic the hormone estrogen. Some scientists worry that adults exposed to them in utero may have fertility problems. Eat fresh or frozen veggies, and don't use plastic containers or plastic wrap when microwaving.
Corrected on 11/20/08: An earlier version of this article misstated the nature of the potential risks from excessive weight gain during pregnancy and the amount of gain considered excessive for overweight women. The benefits to the fetus of maternal exercise also have been clarified.