Taking Zofran During Pregnancy: Is It Safe or Is It Dangerous?

When you’re pregnant, you know that morning sickness can be a major problem, especially in the first trimester. According to the American Pregnancy Association, more than 50% of pregnant women experience morning sickness at one time or another during their pregnancy1 (source).

While some women may get sick and can move on with their day, for others that nausea can be debilitating and can leave them down for the count.

If you’re part of this group, you know exactly what we’re talking about. To say morning sickness is horrible is an understatement, right? You want to not only feel better, but also be able to function again.

One of the big concerns with morning sickness is that it can leave women dehydrated and rob them and their babies of the important nutrients needed during pregnancy.

That’s when the Zofran discussion may come into play. What is it? How can it help? Most importantly, is it safe for you and your baby? Read on to find out so you can decide if Zofran is right for you.

What is Zofran?

If you’ve done any research for morning sickness remedies, chances are Zofran has popped up more than once.

Zofran (otherwise known as Ondansetron), is a drug that is used to prevent nausea and vomiting typically brought on by chemotherapy or radiation2 (source) in cancer patients.

But, it can also be prescribed to treat extreme morning sickness.

How Does Zofran Work For Morning Sickness?

Zofran helps pregnant women deal with morning sickness by blocking the receptors in the body that trigger feelings of nausea.

If you don’t feel nauseous then you won’t have much reason to throw up.

It’s estimated that one in four pregnant women is prescribed Zofran3 (source).

When prescribed, Zofran can be taken in both a tablet and liquid form.

Typically, adults will take one 8mg tablet twice a day or 10ml of liquid twice a day4 (source). With that being said, always consult with your doctor first regarding dosages. As always, better safe than sorry!

Are There Risks Associated With Zofran?

There are side effects when you take just about any drug out there, and Zofran is no different. Some common side effects of taking Zofran include5 (source):

  • Headache
  • Constipation
  • Dizziness
  • Rash

While these are common side effects for anyone taking Zofran, there are more serious concerns for pregnant women. The million dollar question for pregnant women is: will Zofran lead to birth defects?

That answer requires a little history…

Legal Action Involving Zofran

1) 1999

Back in 1999, the FDA warned the makers of Zofran, GlaxoSmithKline, to stop marketing it as an anti-morning sickness drug. The FDA claimed the company never talked about any of the risks associated with Zofran.

2) 2003

In 2003, a whistleblower filed a lawsuit which lead to a domino effect beginning with the U.S. Justice Department taking the company to court. Years later, in 2012 specifically, GlaxoSmithKline paid three billion dollars to settle those claims, among others involving other drugs6 (source).

3) 2013

A year later in 2013, the FDA warned pregnant women not to take Zofran due to an increase in birth defects such as a cleft palate and heart defects.

The FDA also raised an issue regarding pregnant women who had an electrolyte imbalance due to severe morning sickness.

It was concerned about what’s called Serotonin Syndrome, which is a combination of cognitive and behavioral changes that can occur when there is too much serotonin in the body.

The FDA advised that the only safe anti-nausea medicine for pregnant women was Diclegis7 (source).

Since then, there have been hundreds of lawsuits filed by women who took Zofran and claim their baby’s birth defects are a result of them taking the drug.

Studies About Zofran Use And Birth Defects

There have been many studies done where researchers found an increase in these conditions in babies born to pregnant women who took Zofran versus those who did not.

These birth defects include:

  • An increase in heart defects
  • An increase in kidney malfunctions
  • An increase in cleft palates

In 2004, Canadian and Australian researchers published a study that found women who took Zofran during their first trimester had a 3.5% higher chance of having a baby with a major birth defect8.

In another study conducted between 2002 and 2005, Australian researchers found a 20% increase in birth defects in babies born to women who took Zofran during their first trimester.

Swedish researchers who looked at pregnant women who took Zofran during their first trimester between the years 1998 and 2012 found that Zofran was not linked to an increase of severe birth defects.

However, they did find the odds of general heart defects were 1.6 times higher while the odds of a problem with the heart septum were 2.1 times higher9 (source).

Study Supporting Zofran

Despite those studies and the numerous lawsuits filed, there is research to support the use of Zofran during pregnancy.

1) Denmark Study

A study by Denmark researchers, published in the New England Journal of Medicine in 2013, looked at more than 600,000 pregnant women, those who took Zofran and those who did not.

They did not find any increase in birth defects, still births or miscarriage in women who took the drug when compare to those who did not.

There was also no increase in pre-term labor and or low birth weight in those who took Zofran10 (source).

2) UCLA Research

A 2016 study done by a UCLA researcher found that taking Zofran during pregnancy for morning sickness does not lead to birth defects.

The study looked at 1,000 women who took the drug during their pregnancy.

He found that women who took Zofran for morning sickness during their pregnancy did not give birth to more babies with birth defects than women who never took the drug.

Specifically, among 952 infants whose mothers took Zofran for extreme morning sickness, five had heart defects and one had a cleft palate.

Of the 1,286 infants who’s mothers didn’t experience extreme morning sickness and didn’t take Zofran, there were eight heart defects and two cleft palates11 (source).

In fact, his research found that women with morning sickness who took Zofran actually had fewer miscarriages and higher live birth rates than women who did not take the drug for their morning sickness12 (source).

In the study, the researcher said that taking Zofran helped women to get through their pregnancies and have successful births.

Are There Alternatives To Zofran?

If you want to ease your morning sickness but are still unsure if you should be taking Zofran, there are other avenues some doctors recommend.

1) Dietary Changes

Some foods you eat can work to ease the yucky feelings that are often associated with morning sickness.

The American Pregnancy Association advises eating plain, bland foods over spicy foods or foods with a strong odor.

We know they may not taste as good, but if they’re going to stop you from throwing up every hour, it’s a worth a try, right?

Other foods you may want to add to your diet include13 (source):

  • Lemons
  • Ginger
  • Peppermint tea
  • Flavored popsicles

2) Time Your Fluid Intake

You may also want to drink fluids ½ hour before or after meals and not during meals to avoid feeling too full or too empty.

These feelings can also bring on nausea in some women.

3) Vitamin B-6

Talk to your doctor about taking a natural vitamin B-6 supplement. This has also been shown to help with morning sickness.

4) Other Medication

If none of these alternatives to Zofran work, your doctor may prescribe Diclegis to help with your morning sickness.

As of 2018, Diclegis was the only FDA approved prescription drug to treat morning sickness14 (source).

You and your doctor can discuss the pros and cons of taking the drug if you have concerns.

The Bottom Line On Zofran In Pregnancy

Women and babies need to have plenty of nourishment during pregnancy.

Extreme morning sickness can leave a woman depleted of the nutrients both she and her baby need.

If women can experience less nausea and vomiting, this can help make for better nourishment and more successful pregnancies.

Here are a couple of key things to remember as you make your decision on whether taking Zofran for morning sickness is right for you:

  • Zofran is not an FDA-approved drug to treat morning sickness.
  • Some studies have shown an increase in birth defects in babies born to women who took Zofran for morning sickness while others have not.
  • One researcher found no link between taking Zofran and an increase in birth defects; he found fewer miscarriages in women who took Zofran for morning sickness compared to those who did not take it.
  • Lawsuits have been filed claiming Zofran caused birth defects.
  • There are dietary changes that can help to ease morning sickness.

The bottom line on Zofran is that you and your doctor need to discuss whether it’s a good idea for you to take it to relieve your pregnancy problems.

It comes down to how comfortable you are taking the medication, and how confident your doctor is prescribing it to you while keeping your health and the health of your baby a priority.


  1. Morning Sickness. https://americanpregnancy.org/pregnancy-health/morning-sickness-during-pregnancy/. Accessed June 30, 2019.
  2. Ondansetron (Oral Route, Oromucosal Route). https://www.mayoclinic.org/drugs-supplements/ondansetron-oral-route-oromucosal-route/description/drg-20074421. Accessed June 30, 2019.
  3. Zofran for morning sickness: The risks are minimal. https://utswmed.org/medblog/zofran-pregnancy/. Accessed June 30, 2019.
  4. Zofran: Dosage, Side Effects & Pregnancy. https://www.livescience.com/42890-zofran.html. Accessed June 30, 2019.
  5. What Is Zofran (Ondansetron)? https://www.everydayhealth.com/drugs/ondansetron. Accessed June 30, 2019.
  6. Zofran Lawsuits. https://www.consumersafety.org/legal/zofran-lawsuit/. Accessed June 30, 2019.
  7. FDA Warns Against Zofran Use in Pregnancy. https://www.fertilitycenter.com/fertility_cares_blog/fda-warns-against-zofran-use/. Accessed June 30, 2019.
  8. ZOFRAN DURING PREGNANCY: MEDICAL STUDIES SHOW INCREASED ZOFRAN BIRTH DEFECTS. https://www.levinsimes.com/zofran-pregnancy-birth-defects/zofran-pregnancy-medical-studies-show-increased-risk-birth-defects/. Accessed June 30, 2019.
  9. Ondansetron in Pregnancy. https://www.medscape.com/viewarticle/855029. Accessed June 30, 2019.
  10. Ondansetron in Pregnancy and Risk of Adverse Fetal Outcomes. https://www.nejm.org/doi/full/10.1056/NEJMoa1211035. Accessed June 30, 2019.
  11. Study: Zofran Not Tied to Birth Defects. https://www.usnews.com/news/articles/2016-05-09/morning-sickness-drug-zofran-not-tied-to-birth-defects-study-says. Accessed June 30, 2019.
  12. No evidence found linking anti-nausea drug to birth defects. https://www.sciencedaily.com/releases/2016/05/160509085944.htm. Accessed June 30, 2019.
  13. Morning Sickness Relief: Treatment & Supplements. https://americanpregnancy.org/pregnancy-health/morning-sickness-relief/. Accessed June 30, 2019.
  14. Diclegis (doxylamine succinate + pyridoxine hydrochloride DR tablets). https://www.centerwatch.com/drug-information/fda-approved-drugs/drug/1286/diclegis-doxylamine-succinate–pyridoxine-hydrochloride-dr-tablets. Accessed June 30, 2019.

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Medically Reviewed By: Christine Traxler M.D.

Medically Reviewed By: Christine Traxler M.D.

Christine Traxler MD is a retired family practice physician and graduate of the University of Minnesota School of Medicine in 1986. She has worked with patients in rural Minnesota for two decades.

She has written several books on medical topics, and has extensive experience caring for women of childbearing age, women in pregnancy, and menopausal women.

As a writer and editor, she specializes in writing coursework for medical students and other healthcare providers, with a predominance of writing on general medical topics and premedical scientific topics.

She has more than a decade of experience in the writing field, having written books on dermatology, medical assisting, nursing, and pregnancy.

She has written thousands of articles for laypeople and professionals alike on a variety of medical subjects.

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1 thought on “Taking Zofran During Pregnancy: Is It Safe or Is It Dangerous?”

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    I haven’t had any morning sickness during the first trimester of my pregnancy. I only took two vitamins or supplements during my entire pregnancy, namely Hemarate FA and vitamin B12 and my baby was born without any birth defects, weighing 3kg.

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