HealthDay News — First-trimester ondansetron use is associated with a small increased risk for oral cleft but no increased risk for congenital malformations or cardiac malformations, according to a study published in the Dec. 18 issue of the Journal of the American Medical Association.
Krista F. Huybrechts, Ph.D., from Brigham and Women’s Hospital in Boston, and colleagues conducted a retrospective cohort study involving 1,816,414 pregnancies contributed by 1,502,895 women enrolled in Medicaid.
The researchers found that 4.9 percent of the pregnancies were exposed to ondansetron during the first trimester. A cardiac malformation was diagnosed among 14,577 of 1,727,947 unexposed and 835 of 88,467 exposed infants, for absolute risks of 84.4 and 94.4 per 10,000 births, respectively.
For unexposed and exposed infants, the absolute risks of oral clefts were 11.1 and 14.0 per 10,000 births, respectively. For any congenital malformation, the risks were 313.5 and 370.4 per 10,000 births, respectively. The adjusted relative risks were 0.99 (95 percent confidence interval, 0.93 to 1.06) for cardiac malformations, 1.24 (95 percent confidence interval, 1.03 to 1.48) for oral clefts, and 1.01 (95 percent confidence interval, 0.98 to 1.05) for congenital malformations.
“Utilizing a large data set, [this study] provides some reassurance for obstetricians and other clinicians, as well as for pregnant women, regarding the safety of a commonly used medication for nausea and vomiting,” write the authors of an accompanying editorial.
Several authors disclosed financial ties to the pharmaceutical industry.