Use of ondansetron during pregnancy and the risk of major congenital malformations: A systematic review and meta-analysis.

Aims: To investigate whether ondansetron use during pregnancy is associated with increased rates of major or subgroups of malformations.

Methods: PubMed/MEDLINE, Cochrane and Reprotox databases were searched. Observational studies comprising an exposed and control group (healthy and/or disease-matched) were included.

Results: No significant increased risk for major malformations, heart defects, orofacial clefts, genitourinary malformations or hypospadias were identified in our primary analysis. A significant heterogeneity existed for isolated cleft palate. Elevated point estimates and altered statistical significances were present for some of the outcomes among secondary analyses.

Conclusions: Ondansetron use during pregnancy was not associated with a significant increase in rate of major or selected subgroups of malformations in our primary analysis. However, results of the secondary analyses warrant the need for continued surveillance. These results may be reassuring for pregnant women in whom ondansetron use is clinically indicated since the absolute risks of possible concerns appear to be low.