BENDECTIN AND BIRTH-DEFECTS .1. A METAANALYSIS OF THE EPIDEMIOLOGIC STUDIES

''Bendectin''(1) (Doxylamine/Dicyclomine/Pyridoxine) was widely used f or the treatment of nausea and vomiting of pregnancy until 1983, when production was discontinued in the face of lawsuits alleging that the drug caused congenital malformations. We have conducted a meta-analysi s of the 16 cohort and 11 case-control studies that report birth defec ts from Bendectin-exposed pregnancies. This meta-analysis provides an estimate of the relative risk of malformation at birth in association with Bendectin exposure. The pooled estimate of the relative risk of a ny malformation at birth in association with exposure to Bendectin in the first trimester was 0.95 (95% Cl 0.88 to 1.04). Separate analyses were undertaken for cardiac defects, central nervous system defects, n eural tube defects, limb reductions, oral clefts, and genital tract ma lformations. In these categories, the pooled estimates of relative ris k ranged from 0.81 for oral clefts to 1.11 for limb reductions, with a ll 95% confidence intervals enclosing unity. With the exception of stu dies for oral clefts and for pyloric stenosis, tests for heterogeneity of association indicated for each table that all studies were estimat ing the same odds ratio. These studies, as a group, showed no differen ce in the risk of birth defects between those infants whose mothers ha d taken Bendectin during the first trimester of pregnancy and those in fants whose mothers had not. it is unlikely that Bendectin exposure co ntributed to the prevalence of congenital malformations in the populat ion. (C) 1994 Wiley-Liss, Inc.