Some antibiotics are safer than others during pregnancy

Women prescribed penicillins, erythromycins, and cephalosporins for bacterial infections during their first trimester may be reassured that these antibacterial agents are not significantly associated with birth defects, according to researchers at the Centers for Disease Control and Prevention and the University of Arkansas for Medical Sciences in Little Rock.

For women prescribed sulfonamides and nitrofurantoins during pregnancy, the news is less rosy.

The population-based, multisite, case-controlled study compared 13,155 women whose pregnancies were affected by 1 of more than 30 types of birth defects with 4,941 matched controls. Reported use of antibiotics increased during the first trimester. Of these, sulfonamides were associated with anencephaly, hypoplastic left heart syndrome, coarctation of the aorta, choanal atresia, transverse limb deficiency, and diaphragmatic hernia. Nitrofurantonins were associated with anophthalmia or microphthalmos, septal defects, and cleft lip or palate. However, infants of women treated with erythromycins, penicillins, cephalosporins, and quinolones had minimal risk of birth defects.