A population-based case-control teratological study of furosemide treatment during pregnancy

Objective: To study the human teratogenic potential of furosemide (frusemid e) treatment during pregnancy. Design and Setting: This study used pair analysis of newborn infants with c ongenital abnormalities and matched healthy controls. Cases and controls we re from the large population-based dataset of the Hungarian Case-Control Su rveillance of Congenital Abnormalities (HCCSCA), 1980 to 1996. information on maternal drug exposure was obtained from the parents by means of questio nnaires, antenatal care logbooks and interviews. Study Participants: Women who had babies without any defects (population co ntrol group) and women who had offspring with congenital abnormalities. Main Outcome Measures: Congenital abnormalities diagnosed during the second and third trimester and postnatally from birth until the age of 1 year. Results: Of 38 151 population controls, 450 (1.2%) had mothers who were exp osed to furosemide treatment during pregnancy; the corresponding figures fo r cases were 22 865 and 246 (1.1%). The odds ratio was 0.9 (95% confidence interval 0.8 to 1.1). The distribution of congenital abnormalities in infan ts born to all furosemide recipients did not differ significantly from the expected distribution on the basis of baseline rates in the HCCSCA. Analysi s of the extent of medically documented furosemide treatment during the sec ond and third months of gestation, i.e. in the critical period for most maj or congenital abnormalities, did not indicate a teratogenic potential of fu rosemide, either by comparing the total control group with different congen ital abnormality groups or by case-matched control pair analysis. Conclusion: Maternal exposure to furosemide during pregnancy does not prese nt a detectable teratogenic risk to the: fetus; however, the number of preg nant women who were treated with furosemide in the critical period of most major congenital abnormalities was limited (15 controls vs 14 cases).