Antibacterial medication use during pregnancy and risk of birth defects: National Birth Defects Prevention Study.

OBJECTIVE

To estimate the association between antibacterial medications and selected birth defects.

DESIGN, SETTING, AND

PARTICIPANTS

Population-based, multisite, case-control study of women who had pregnancies affected by 1 of more than 30 eligible major birth defects identified via birth defect surveillance programs in 10 states (n = 13 155) and control women randomly selected from the same geographical regions (n = 4941).

MAIN EXPOSURE: Reported maternal use of antibacterials (1 month before pregnancy through the end of the first trimester).

MAIN OUTCOME MEASURE: Odds ratios (ORs) measuring the association between antibacterial use and selected birth defects adjusted for potential confounders.

RESULTS

The reported use of antibacterials increased during pregnancy, peaking during the third month. Sulfonamides were associated with anencephaly (adjusted OR [AOR] = 3.4; 95% confidence interval [CI], 1.3-8.8), hypoplastic left heart syndrome (AOR = 3.2; 95% CI, 1.3-7.6), coarctation of the aorta (AOR = 2.7; 95% CI, 1.3-5.6), choanal atresia (AOR = 8.0; 95% CI, 2.7-23.5), transverse limb deficiency (AOR = 2.5; 95% CI, 1.0-5.9), and diaphragmatic hernia (AOR = 2.4; 95% CI, 1.1-5.4). Nitrofurantoins were associated with anophthalmia or microphthalmos (AOR = 3.7; 95% CI, 1.1-12.2), hypoplastic left heart syndrome (AOR = 4.2; 95% CI, 1.9-9.1), atrial septal defects (AOR = 1.9; 95% CI, 1.1-3.4), and cleft lip with cleft palate (AOR = 2.1; 95% CI, 1.2-3.9). Other antibacterial agents that showed associations included erythromycins (2 defects), penicillins (1 defect), cephalosporins (1 defect), and quinolones (1 defect).

CONCLUSIONS

Reassuringly, penicillins, erythromycins, and cephalosporins, although used commonly by pregnant women, were not associated with many birth defects. Sulfonamides and nitrofurantoins were associated with several birth defects, indicating a need for additional scrutiny.