Large Danish Study finds Zofran® Increases Risk of Heart Birth Defects

A study of all women giving birth in Denmark between 1997 and 2010 has found that women who take Zofran during early pregnancy double their risk of giving birth to a child with septal defects of the heart. A septal defect is a hole in the wall (septum) between the two upper chambers (atria) or the two lower chambers (ventricles) of the heart. Babies with septal defects may develop serious symptoms, requiring surgery to prevent permanent damage.

Researchers at the Copenhagen University Hospital Bispebjerg, Copenhagen, Denmark, were led by Jon T. Andersen, MD, Ph.D., of the University’s Department of Clinical Pharmacology. Dr. Andersen presented the results of his study on August 26, 2013, at the 29th International Conference on Pharmacoepidemiology & Therapeutic Risk Management in Montreal, Canada.

According to the study abstract presented at the conference, the researchers identified over 897,018 births. About 1,248 women redeemed a prescription for ondansetron during early pregnancy for treatment of nausea and vomiting in pregnancy (NVP). 4.7% of the women who took ondansetron had offspring with a congenital malformation, compared to 3.5% of the women in the unexposed group. The conference abstract reported a two-fold increase in the prevalence of heart defects in the children who were exposed to ondansetron during early pregnancy.

Summary Information

Ondansetron use in early pregnancy and the risk of congenital malformations—a registry based nationwide cohort study

Jon T Andersen, MD, PhD 1; Nadia L Andersen, MD, PhD 2; Henrik E Poulsen, MD, DMSc 1; Espen Jimenez-Solem, MD, PhD1

  1. Department of Clinical Pharmacology, Copenhagen University Hospital Bispebjerg, Copenhagen, Denmark
  2. Copenhagen Mental Health Center, Copenhagen, Denmark

Abstract presented at: 29th International Conference on Pharmacoepidemiology & Therapeutic Risk Management; August 25–28, 2013; Montreal, Canada. Abstract 25, Pregnancy Session 1.
Pharmacoepidemiol Drug Saf. 2013;22(suppl 1):13–14

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