A population-based case-control teratologic study of nalidixic acid

Objective: Quinolones, mainly nalidixic acid, are frequently used in Hungar y to treat bacterial infections in pregnant women, but so far no controlled epidemiological studies of congenital abnormalities among infants born to women treated with nalidixic acid during pregnancy have been reported. Meth ods: The analysis of oral nalidixic acid use during pregnancy in the mother s of cases with congenital abnormalities and in their matched population co ntrols without congenital abnormality was carried out in the population-bas ed dataset of the Hungarian Case-Control Surveillance of Congenital Abnorma lities between 1980 and 1996. The study included 22865 women who had newbor ns or fetuses with congenital abnormalities, and 38151 pregnant women who h ad newborn infants without any defects (controls). Results: In the case gro up, 242 (1.1%) and in the control group, 377 (1.0%) pregnant women were tre ated with nalidixic acid (crude OR: 1.1 with 95% CI: 0.9-1.3). Seventeen di fferent congenital abnormality groups were evaluated and a higher prevalenc e of pyloric stenosis was found in seven case infants born to mothers who r eceived nalidixic acid treatment during the last months of pregnancy (adjus ted OR: 11.0 with 95% CI: 1.3-91.4). Conclusions: Treatment with nalidixic acid during pregnancy may increase the risk of pyloric stenosis, though the chance effects cannot be excluded. (C) 2001 International Federation of Gy necology and Obstetrics. All rights reserved.