Ondansetron in pregnancy and risk of adverse fetal outcomes in the United States

This is an analysis of fetal outcome in pregnancies exposed to ondansetron to treat Hyperemesis Gravidarum (HG). In this retrospective cohort study, U.S. data on outcome were collected on 1070 pregnancies exposed to ondansetron and compared to outcomes in two control groups: 771 pregnancies in women with a history of HG with no ondansetron exposure and 1555 pregnancies with neither a history of HG nor ondansetron exposure. Ventricular septal defects were reported in 2/952 of infants in the HG/Ondansetron-exposure group and 4/1286 in the No HG/No Ondansetron-exposure group. Cleft palate was reported in 1/952 live births in the HG/Ondansetron and 2/1286 in the No HG/No Ondansetron-exposure groups. Women with a history of HG who took ondansetron reported less miscarriages and terminations, and higher live birth rates. The overall results do not support evidence of teratogenicity of ondansetron.