According to the National Institutes of Health and other published medical research, nausea and vomiting during pregnancy occurs in 80-85% of pregnant women. Several medications can be used to alleviate what is commonly referred to as morning sickness, but there is insufficient data on how these drugs correlate with birth defects. Some anti-nausea medications, such as Bendectin, which were previously believed to be safe for pregnant women, were subsequently removed from the market after birth defects were observed.


The majority of pregnancy-induced nausea and vomiting is experienced during the first trimester of pregnancy, when many of the fetus’s primary bodily systems and functions are still developing, making the fetus susceptible to serious side effects from in utero exposure to toxins.

Zofran Use During Pregnancy

There is an increasing trend to prescribe Zofran (ondansetron) for nausea and vomiting in pregnant women, even though its safety for use during pregnancy remains unknown. This is largely because there is no FDA-approved drug for this condition. Zofran is not labeled for use to combat nausea and vomiting in pregnancy in either the United States or Canada.

Studies, including one published in China, have found that the drug is teratogenic (able to cause congenital birth defects) because it is readily able to pass through the placenta in early pregnancy in a concentration that is high enough to cause abnormal fetal development. The Slone Epidemiology Center and the Centers for Disease Control and Prevention found that women exposed to the 5HT3-receptor antagonist Zofran during the first trimester of pregnancy were observed to have a 2.37 times increased risk of having a child born with a cleft palate birth defect. 

Although the medication has proven to be effective against nausea, the U.S. Food and Drug Administration (FDA) has issued an updated warning that it is continuing to evaluate whether taking Zofran while pregnant may cause serious birth defects or complications for the mother. This medicine is still being prescribed to many women who may not be aware of potential side effects.

What is Zofran Used For?

Zofran was developed to aid cancer patients who face nausea as a result of surgery, chemotherapy, and radiation. The FDA has not restricted the sale of Zofran, and doctors are free to prescribe it as they choose, regardless of its intended purpose. Although doctors can legally prescribe Zofran to pregnant women, patients have a right to know the potential risks of a medication, and doctors must advise pregnant women of the hazards posed to the mother and unborn child.

Zofran is typically administered via an orally swallowed tablet, at a rate of once or twice per day. The drug helps to block chemicals in the body that cause nausea, and is most commonly prescribed to women facing extreme bouts of nausea and vomiting. Since chemotherapy patients and pregnant women who are already nauseous and vomiting will potentially throw up a tablet, the medication is also available in dissolvable wafers and injections.

What Birth Defects Can Zofran Cause?

Pregnant women in many countries around the world are prescribed Zofran for off-label use. It is important for the medical and scientific community to accumulate as many patient outcomes as possible to really see the overall safety of the drug’s use during pregnancy.

Infants born to mothers who took Zofran during pregnancy may be born with malformations of the mouth, including a cleft lip or cleft palate. A cleft palate refers to a split in the roof of the mouth, while a cleft lip includes a gather or split in the mouth area. These disfigurations of the face can range from visible facial marks to massive developmental shortcomings, which can cause difficulty eating or breathing. Although modern surgeries can sometimes correct these birth defects, a child may face a lifetime of scarring or injuries so severe that they cannot be fully corrected. According to a study conducted by the National Center for Biotechnology Information, taking Zofran during pregnancy may increase a baby’s chances of being born with a cleft palate twice over.

Severe birth complications caused by Zofran also include defects in the development of the infant’s heart. A baby may face life-threatening complications during the pregnancy, birth, or for the rest of his or her life as a result of defects in the growth of their heart, including congenital heart defects that threaten their life.

At least one study showed that women dispensed ondanestron at any time during pregnancy had a 2.0 times increased risk of their baby being born with an APGAR score after 5 minutes of less than 6. This commonly used measurement for a newborn’s health determines the condition of the infant on a scale of 1 to 10, with a score of 6 or lower after 5 minutes indicating that the baby may need medical assistance. The same study found an increased risk of a major birth defect, preterm birth, and shorter birth length.

An article in Reproductive Toxicology found that the risks for a cardiovascular defect, most notably a cardiac septum defect were increased and statistically significant. This indicates an increased risk that mothers who take Zofran during pregnancy will give birth to a baby with a “hole in the heart,” also known as an atrial septal defect or a ventral septal defect. The article cites a Denmark study showing a 2.0 times increased risk of congenital heart malformation after first trimester exposure to Zofran.

Blizzard Law PLLC Birth Defects Lawyers

If you or someone you know took Zofran during pregnancy for nausea, and your child was born with birth defects such as a cleft palate or congenital heart defect, you may be entitled to compensation. Taking on pharmaceutical companies is an intimidating prospect, but the attorneys of Blizzard Law PLLC have experience in a wide range of medical and pharmaceutical cases. Our trial lawyers have served in national litigation leadership positions involving cases where medications taken during pregnancy have caused birth defects. We have the experience you need on your side to make the best decision for your family. Contact us today.