While no drug -- prescription or over-the-counter (OTC) -- has been proven "absolutely safe when you are pregnant," many medications are thought to be safe for the mother and developing fetus, according to the National Institutes of Health's Center for the Evaluation of Risks to Human Reproduction.
Particularly for women with chronic medical conditions like asthma, diabetes and high blood pressure, the risks of allowing health problems to go uncontrolled during pregnancy may outweigh the risks of the medications typically prescribed for them, say experts. This stance assumes that the drugs are taken under a doctor's supervision, and then only for the shortest time and at the lowest dose needed.
Calculating Risk The Food and Drug Administration (FDA) uses five risk categories -- from A, the least problematic, to X, the most dangerous -- to rank the safety of prescription drugs during pregnancy. The FDA does not categorize OTC drugs but requires them to carry at least this standard warning, "If pregnant or breast-feeding, ask a health care professional before use." Tylenol [acetaminophen], for example, carries this warning and is generally considered safe to take during pregnancy. Some OTC drugs must carry a more specific warning. Labels on aspirin, naproxen sodium (Aleve) and ibuprofen (Advil, Motrin) advise against use during the last trimester because they may harm the fetus or cause complications during delivery.
The FDA is currently revising its pregnancy risk categories; below is where some drugs currently reside:
Category A Includes drugs where studies did not indicate a risk during the first trimester and produced no evidence of risk in later pregnancy. Very few drugs fall into this category; thyroid medications are one example.
Category B Includes medications that have been used often during pregnancy and do not seem to cause major birth defects or other problems. Examples: some antibiotics, famotidine (Pepcid) and some types of insulin. The corticosteroid nasal spray Rhinocort Aqua (budesonide) was moved into this class last year from Category C, where many allergy and asthma drugs reside.
Category C Includes drugs that may be more likely to cause complications for the mother or the baby and those for which there are insufficient safety data. Examples: fluconazole (Diflucan), ciprofloxacin (Cipro), fexofenadine (Allegra) and some antidepressants.
Category D Includes drugs that are known to impose health risk for the fetus. The placement of a drug into this category indicates that "positive evidence of human fetal risk exists, but the benefits from use in pregnant women may be acceptable despite the risk," states a report by the American College of Obstetricians and Gynecologists (ACOG). Examples: chemotherapy drugs and phenytoin (Dilantin).
Category X Includes medications demonstrated to cause birth defects. Indicates that "risk in pregnant women clearly outweighs any possible benefit," states the ACOG report. Includes the acne drug Accutane and psoriasis medications Tegison and Soriatane.
Register to Help One way drug manufacturers learn about the safety of medications is through pregnancy registries -- studies that enroll pregnant women after they've begun taking a drug but before the birth of the baby. "Babies born to women taking a particular medicine are compared with babies of women not taking the medicine," reports the National Women's Health Information Center. For a list of registries currently accepting participants, see www.fda.gov/womens/registries/.
-- January W. Payne