MedWire News: US researchers have found significant associations between the maternal use of sulfonamide and nitrofurantoin antibiotics during pregnancy and various birth defects, indicating a need for further scrutiny of these compounds.

Using data collected from birth defect surveillance programs in 10 US states, the researchers identified 13,155 women who gave birth to babies affected by one major birth defect. The control group comprised 4,941 randomly selected women who delivered a healthy child.

The researchers found that antibacterial use increased during pregnancy in all women, peaking in the third month. Overall, approximately 29 percent of all women used antibacterials between 3 months before pregnancy and the end of pregnancy.

Penicillins, erythromycins, and cephalosphorins, although most commonly used by pregnant women, were not associated with many birth defects.

The use of sulfonamides was associated with more birth defects than any other antibacterial class, including diaphragmatic hernia, transverse limb deficiency, coarctation of the aorta, hypoplastic left heart syndrome, and anencephaly (adjusted odds ratio [AOR] ranging from 2.4 to 3.4), The strongest association was with choanal atresia(AOR = 8.0).

Nitrofurantoins were associated with atrial septal defects, cleft lip with cleft palate, anophthalmia, and hypoplastic left heart syndrome (AOR ranging from 1.9 to 4.2).

“This study could not determine the safety of drugs during pregnancy, but the lack of widespread increased risk associated with many classes of antibacterials used during pregnancy should be reassuring,” say Krista Crider (Centers for Disease Control and Prevention, Atlanta, Georgia) and co-authors.

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