• Alcohol: Bad news for the 10% of pregnant women who report ingesting alcohol and especially for the 2% who binge drink during pregnancy: There’s no safe level of alcohol intake during pregnancy. Federal data suggest that 1 in 6,000 U.S. newborns have fetal alcohol syndrome or fetal alcohol spectrum disorder.
• Nicotine: The tricky problem with nicotine is not just that it’s "associated with everything bad," Dr. Autry said, but that people know it’s bad, so an estimated 25%-50% of pregnant women don’t disclose that they smoke. Smoking in pregnancy is associated with miscarriage, abruption, ectopic pregnancy, preterm delivery, and more. Among mothers who quit smoking during pregnancy, 90% relapse after delivery. "It’s really important to continue the smoking cessation discussion during pregnancy," she said. "It’s important to say, ‘If you go back to smoking, don’t do it in the house, because it’s bad for the kid.’"
• Hot tubs: Soaking during the first trimester, or any time in pregnancy in water heated to 100 F or higher, is potentially teratogenic, two studies suggest. Maternal hyperthermia from hot tubs has been associated with first trimester fetal loss and with a nearly doubling in risk for neural tube defects.
• Exercise: The general recommendation to get 30 minutes or more of moderate exercise on most days applies to pregnant women unless they have some medical or obstetric complication. Exercise is believed to help prevent gestational diabetes, reduce the risk for preeclampsia and premature labor, and decrease the risk for postpartum depression. ACOG recommends avoiding scuba diving, contact sports, and supine activities or motionless standings. Yoga is fine, but avoid so-called "hot yoga," Dr. Autry said.
For high-performance athletes, exertion at high altitudes appears to be safe. There is no pregnancy-specific maximum heart rate.
"Just don’t do anything in pregnancy that you wouldn’t do before," Dr. Autry said. If you’ve never run a marathon, pregnancy is not the time to start.
• Hair dye: There are no data to support the idea of teratogenic effects from the chemicals in hair dyes. But it’s probably still a good idea to look at the labels and choose products with ingredients that are less long acting and organic, if possible, she said.
For resources on environmental exposures during pregnancy, see the university’s Program on Reproductive Health and the Environment.
Dr. Autry reported having no financial disclosures.
On Twitter @sherryboschert