Despite Zofran Birth Defect Questions, OB/GYN Group Stands Behind Use for Morning Sickness

Despite growing concerns about the link between Zofran and birth defects, a prominent medical association representing gynecologists is advising doctors not to shy away from prescribing the anti-nausea drug to treat morning sickness among pregnant women, even though the FDA has not approved the drug for that purpose. 

The American College of Obstetricians and Gynecologists (ACOG) indicates that it is important to treat nausea and vomiting early during pregnancy, in order to stop it from progressing to a more serious condition, known as hyperemesis gravidarum. It’s recommendations were published in the May issue of Obstetrics & Gynecology.

Zofran (ondansetron) is GlaxoSmithKline anti-nausea drug that is only approved by the FDA for use among cancer patients undergoing chemotherapy and among others after surgery. While the drug has never been established as safe and effective for use to treat morning sickness, it is commonly prescribed “off-label” to pregnant women, accounting for a large portion of the sales.

The recommendation comes after several studies published in recent years have raised questions about the side effects of Zofran use during early pregnancy, with findings suggesting that children may face a risk of congenital heart defects, cleft palate, cleft lip and other birth defects.

ACOG indicates that it is not convinced yet by the evidence so far that Zofran represents a significant birth defect risk.

“Recent studies have provided conflicting findings on the safety of ondansetron during pregnancy,” the group wrote. “It is the authors’ opinion that current data do not support a reluctance to treat women with ondansetron in clinical practice.”

The recommendation has raised serious questions, as the drug maker has also never conducted thorough studies to establish that Zofran is safe in pregnancy.

Zofran Pregnancy Risks

As early as 2006, a study published by Hong Kong researchers confirmed that Zofran crosses the placenta in significant amounts when taken by pregnant women, first raising questions about whether the drug may cause developmental problems or birth defects.

In November 2011, a study published in the medical journal Birth Defects Research Part A: Clinical and Molecular Teratology concluded that women may be 2.37 times more likely to give birth to a child with a cleft palate following Zofran use. This may leave children with a severe facial deformity, which can occur when development of the fetus is impacted during the first trimester.

Additional studies have also identified potential Zofran heart defect risks. An August 2013 study that reviewed data on more than 900,000 pregnancies in the Danish Medical Birth Registry found that children may be two to four times more likely to suffer a septal defect, involving holes in the heart, following Zofran exposure. Heart murmurs following Zofran use during pregnancy may be a sign or symptom of these heart problems.

More recently, a study also published by the medical journal Reproductive Toxicology in October 2014 found that there is a statistically significant increased risk for certain heart defects with Zofran use early in pregnancy.

Over the past year, a growing number of families throughout the United States have filed a Zofran birth defect lawsuit against GlaxoSmithKline, alleging that the drug maker placed their desire for profits before consumer safety, withholding information and warnings about the pregnancy risks from consumers and the medical community.