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Zofran Linked to Birth Defects

The anti-nausea drug Zofran® has often been prescribed off-label to pregnant women suffering from serious morning sickness.  However, the evidence is growing that taking this drug may cause women to give birth to babies with a variety of birth defects.

Zofran was approved in 1991 by the Food and Drug Administration (FDA) for treating nausea and vomiting in cancer patients receiving chemotherapy and surgical patients with reactions to anesthesia. However physicians also prescribed it for severe nausea and vomiting during the first trimester of pregnancy.

Studies About the Safety of Zofran During Pregnancy

A recent article in the American Journal of Obstetrics and Gynecology[1] reported in drugwatch.com found that the babies of women who took Zofran faced a “two-fold increase” in the risk of heart problems in general and a 30 percent chance of suffering serious congenital heart malformations. The study, conducted in August 2013 among 900,000 Danish women, found that around one million pregnant women each year were exposed to Zofran (or the generic version ondansetron) worldwide.

The study also compared Zofran with other anti-nausea drugs and found that there were safer alternatives to the medication, such as doxylamine and pyridoxine. The conclusion: There is no reason to expose women to an unproven drug that carries such risks when there are safer alternatives.

Although early research was inconclusive, more recent studies indicate that there are significant risks to taking Zofran during pregnancy.  For example, a study published in 2013 in the New England Journal of Medicine[2] found that the drug posed no significant risks.  However, the majority of women in the study took the drug after 10 weeks, which is when the vulnerability of fetuses to drugs and other external substances lessens. The more recent Danish study[3], which studied women during the first trimester, when severe nausea and vomiting usually occur, found that 58 women out of the 1,248 who were prescribed the drug in the first trimester had babies with birth defects, a thirty percent increase over the control group.

Birth Defects Linked To Zofran

Babies whose mothers took the drug in the first three months of pregnancy have been born with a variety of birth defects, including:

  • Cleft Palate
  • Cleft Lip
  • Heart Defects (Cardiac Murmurs and Arrhythmia)
  • Limb Defects (Musculoskeletal abnormalities)
  • Kidney Defects
  • Lawsuit Against Zofran’s Manufacturer

The U.S. Department of Justice brought a lawsuit against the manufacturer of Zofran, GlaxoSmithKline for “unlawful promotion” and failure to include research data in safety reports on the drugs it manufactured and sold. The company pleaded guilty in 2012 to illegally advertising the drug as a morning sickness pill and agreed to pay $3 billion to settle the suit.

At least two individual lawsuits have been filed against GlaxoSmithKline, one in Minnesota and another in Massachusetts. Moreover, the manufacturer has been accused of illegal doctors to prescribe Zofran off-label, something that the company is known for doing.


Zofran® is a registered trademark of GlaxoSmithKline, PLC.

Do not stop taking medications except on your doctor’s advice.


[1] Koren, Gideon, “Treating morning sickness in the United States—changes in prescribing are needed,”  American Journal of Obstetrics and Gynecology, vol. 21, issue 6, December 2014, pp. 602-606.

[2] Pasternak, Bjorn, et. al., “Ondansetron in Pregnancy and Risk of Adverse Fetal Outcomes,” New England Journal of Medicine, vol. 368, February 28, 2013, pp. 814-823.

[3] Andersen JT, Jimenez-Solem E, Andersen NL, Poulsen HE. Ondansetron use in early pregnancy and the risk of congenital malformations—a registry based nationwide cohort study. 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.