Study Suggests Use of Zofran for Extreme Morning Sickness May be Safe But Caution Advised

By Kristine Hartvigsen on January 20th, 2017

Before Kate Middleton, the Duchess of Cambridge, was hospitalized with it during her first pregnancy, few commoners had even heard of hyperemesis gravidarum (HG). And many women with severe pregnancy-related nausea (morning sickness) did not receive an awful lot of attention or sympathy. After all, it was a normal part of pregnancy. Eat some crackers, they are advised. Drink some ginger ale.

Legitimate, severe HG like the Duchess endured, however, can escalate to the point where it can be life-threatening.

It is somewhat rare, estimated to affect about 3% of pregnancies, and is believed to result from elevated levels of the pregnancy hormones hCG and progesterone. Sufferers may experience constant nausea and vomiting so intense that some even suffer detached retinas and cracked ribs. They also can lose up to 5% of their body weight and become very dehydrated. This occurs at a time when both mother and fetus need nutrition, and a really sick mom is unlikely to eat much.

What the Duchess and many other women with HG were prescribed was a medication called ondansetron (brand name Zofran). The Food and Drug Administration (FDA) has long approved the medication for treatment of surgery-, chemotherapy- or radiation-related nausea. The FDA never has approved Zofran for pregnancy-related nausea, but many physicians for years have prescribed it for off-label use when nothing else seems to work.

A 2014 Swedish study linking maternal use of ondansetron with infant cardiovascular defects raised intense concern about the drug’s risk for heart malformations and other birth defects. This may have prompted a massive rush of still-ongoing lawsuits against the companies producing the drug (GlaxoSmithKline and later Novartis). Those risks were disputed and remained largely unknown due to a dearth of research on the topic until the recent publication of a study published this month in the journal Reproductive Toxicology. The study’s author, a researcher at the University of California Los Angeles (UCLA), could find no significant evidence that ondansetron increases the risk of birth defects. In addition, the study found that women with HG who took ondansetron had fewer miscarriages and higher live birth rates.

The study’s author noted the possibility that adverse effects experienced by women with HG might be attributable to dehydration, stress, and poor nutrition caused by the HG and not the ondansetron itself. She cautioned, however, that further research is indicated and that women with HG should consult with their physicians and make informed decisions about their treatment.

This blog provides general information and discussion about healthcare-related subjects. The content and linked materials provided are not intended and should not be construed as medical advice. If the reader is an expectant mother with a medical concern, she should consult with an appropriately licensed physician or healthcare provider.

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