No Evidence Showing Zofran is linked to Birth Defects

By NLM [Public domain], via Wikimedia Commons

Pregnant women who are suffering from extreme morning sickness will sometimes take ondansetron or Zofran, to help with debilitating nausea and vomiting. However, there have been two studies that have found the drug could increase the risk of cleft palate and heart defects in babies who are exposed in utero.

The Study

In a new study performed by the University of California, Los Angeles there was no evidence found to link the anti-nausea drug to an increased risk of fetal birth defects. In fact, women who use Zofran during pregnancy reported fewer miscarriages and pregnancy terminations and have a higher rate of live births than women with extreme morning sickness, who didn’t take the medication, said main study author Marlena Fejzo, an associate researcher at the David Geffen School of Medicine at UCLA. More than 190 lawsuits have been filed since 2015, against the manufacturer of the drug.

The lawsuits allege that birth defects were caused by pregnant women being exposed to Zofran. This study may help women make more informed choices about whether to expose their fetuses to the drug.

Fejzo said, “This is the first study describing fetal outcome for more than 1,000 exposures to Zofran in the United States. I believe this data is critical to guide future decision-making regarding prescribing what is one of the most effective is and most commonly prescribed off-label treatments for nausea and vomiting. The overall results do not support an increased risk of birth defects.”
The results of the study were published in the May 9th, 2016 edition of Reproductive Toxicology.

The Kate Middleton, Duchess of Cambridge, experienced extreme morning sickness or Hyperemesis Gravidum (HG), during both of her pregnancies. The cause of HG is not known, but the symptoms are very intense, the continual nausea and vomiting can be so severe and violent that women can suffer from blown eardrums, detached retinas, cracked ribs and torn esophagi. The symptoms of the condition can last for months or throughout a woman’s pregnancy. Many women who have HG will require IV fluids and feeding tubes and are often hospitalized multiple times.


In this reflective study, data on outcomes were collected on 1,070 pregnancies exposed to Zofran and compared to outcomes in two control groups, 771 pregnancies in women with a history of HG with no Zofran exposure and 1,555 pregnancies with neither a history of HG nor Zofran exposure. There were heart defects reported in 952 infants in the HG/Zofran-exposure group and in eight of the 1,286 infants born to women who did not have HG and weren’t exposed to Zofran. Cleft palate defects were reported in one of the 952 live births in the HG/Zofran-exposure group and in two of the 1,286 in women who didn’t take Zofran nor had HG.

Fejzo said, “What was really significant to me was that women with extreme morning sickness who took Zofran reported fewer miscarriages and terminations and experienced higher live birth rates. Taking this medication helped them get through their pregnancies and gave them their desired outcome, a live birth.”


The information provided on is designed to support, not replace, the relationship that exists between a patient/site visitor and his/her health professional. This information is solely for informational and educational purposes. The publication of this information does not constitute the practice of medicine, and this information does not replace the advice of your physician or other health care provider. Neither the owners or employees of nor the author(s) of site content take responsibility for any possible consequences from any treatment, procedure, exercise, dietary modification, action or application of medication which results from reading this site. Always speak with your primary health care provider before engaging in any form of self treatment. See our Legal Statement for more details.

Fertility Clinics Directory

Find a Fertility Clinic

If you or a loved one is suffering from infertility and needs help conceiving then we are here to offer help in any way we can. We have over 450 Fertility Clinics listed on our Directory. Click here to search for a Fertility Clinic that is right for you.