A 20-year-old woman presents to your office for routine well-woman examination. She has a history of acne, for which she takes minocycline and isotretinoin on a daily basis. She has a history of epilepsy that is wellcontrolled on valproic acid. She also takes a combined oral contraceptive birth control pill containing norethindrone acetate and ethinyl estradiol. She is a nonsmoker but drinks alcohol on a daily basis. She is concerned about the effectiveness of her birth control pill, given all the medications that she takes. She is particularly worried about the effects of her medications on a developing fetus in the event of an unintended pregnancy.
Which of the following substances that she ingests has the lowest potential to cause birth defects?
A. AlcoholAlcohol is an enormous contributor to otherwise preventable birth defects. Sequelae include retardation of intrauterine growth, craniofacial abnormalities, and mental retardation. The occasional drink in pregnancy has not been proved to be deleterious, but is still not recommended. Isotretinoin (accutane) is a powerful drug for acne that has enormous potential for producing congenital anomalies when ingested in early pregnancy; it should never be used in pregnancy. Tetracyclines interfere with development of bone and can lead to stained teeth in children. Progesterones have been implicated in multiple birth defects, but controlled studies have failed to demonstrate a significant association with increased risk. Patients who have inadvertently become pregnant while on birth control pills should be reassured that the incidence of birth defects is no higher for them than for the general population. Valproic acid is used for epilepsy and can be associated with a spectrum of abnormalities, including NTDs and abnormal facial features.