Cigarettes and secondhand smoke
Studies have conclusively proven that smoking and pregnancy don’t mix: Babies born to mothers who smoke weigh less on average. Doctors suspect the lower birth weight is due to restricted blood flow, which may also impair the passage of nutrients through the placenta to the baby. The carbon monoxide in cigarette smoke that enters the mother’s bloodstream also reduces the amount of oxygen that reaches the uterus. For these reasons, doctors advise pregnant women to also steer clear of secondhand smoke.
Used in moderation, coffee and other caffeinated foods and beverages probably are not a problem. However, consuming more than 300 to 400 milligrams of caffeine a day (the equivalent of three to four 8-ounce cups of coffee) increases the risk of miscarriage, according to Magriples. When tallying your daily caffeine consumption, remember to count colas, iced tea and chocolate.
Cold and flu medications
Antihistamines such as Benadryl and Chlortrimeton are safe, as are most cold remedies except for decongestants. Because decongestants work by constricting blood vessels, they can cause high blood pressure and uterine contractions. To relieve a stuffy nose, try a saline nasal spray instead.
Many cold and flu products contain multiple ingredients that treat several symptoms at once. When selecting such products, make sure to read the labels, and take medications that treat only your symptoms, says Towers, author of I’m Pregnant & I Have a Cold: Are Over-the-Counter Drugs Safe to Use? (RBC Press Inc., 1999). For instance, if your primary symptom is a runny nose, take only an antihistamine.
The safest cough suppressant for pregnant women is dextromethorphan. Some medications indicate this active ingredient with a “D” or a “DM” in their names, such as Robitussin-DM.