Did you use Zofran during pregnancy to combat morning sickness? A fellow blogger recently voiced her concerns about taking the drug due to some fairly new warnings about possible birth defects. My initial response urged her to weigh the risks and benefits: “You have to weigh the risks and benefits. How sick are you? Is it to the point that meds are the only thing keeping you and baby healthy? Or can you get by without the meds while still staying healthy? Nothing in life is risk-free.” Putting on my librarian hat, I then did a little research on the medication.
According to the 2012 edition of Medications and Mothers’ Milk by Thomas W. Hale, an important source of information on medication during pregnancy and breastfeeding, Zofran (ondansetron) is a category B drug:
B. No Evidence of Risk in Humans
Adequate, well-controlled studies in pregnant women have not shown increased risk of fetal abnormalities despite adverse findings in animals, or, in the absence of adequate human studies, animal studies show no fetal risk. The chance of fetal harm is remote but remains a possibility.
Drugs Used in Pregnancy also lists Zofran as a category B drug. Zofran is therefore considered safer, although not the safest, for pregnant women.
Researchers from The University of Toronto also concluded the safety of Zofran during pregnancy in a 2004 study published in BJOG: An International Journal of Obstetrics & Gynaecology. The study concluded that the drug “does not appear (although the sample size is limited) to be associated with an increased risk for major malformations above baseline.” Despite a small cohort of only 176 pregnancies, the researchers did not find any statistical differences between the women taking Zofran during pregnancy and the control group.
A more recent 2013 study published in the journal BioMed Research International also failed to find a link between birth defects or other adverse birth outcomes and the drug Zofran. Upon looking at data from 96,968 births from 2002 to 2005 including 251 to whom Zofran was dispensed, the researchers “did not detect any adverse outcomes from the use of ondansetron in pregnancy but could not conclude that ondansetron is safe to use in pregnancy.” In other words, Zofran appears okay for pregnant women, although the researchers could not definitively conclude the safety of Zofran during pregnancy. Another 2013 study published in the New England Journal of Medicine that analyzed data from a historical cohort of 608,385 pregnancies in Denmark also determined that taking Zofran during pregnancy was not associated with an increased risk of adverse birth outcomes.
Additional Information on Zofran and Pregnancy Safety
When dealing with severe morning sickness, or hyperemesis gravidarum, the potential benefits of taking Zofran must be carefully weighed against the possible risks. Hyperemesis gravidarum can lead to dehydration, malnutrition, and other complications that may endanger both the mother and the baby, making medication necessary in some cases.
The classification of Zofran as a Category B drug by both Medications and Mothers’ Milk and Drugs Used in Pregnancy indicates that while the drug is relatively safer than others, it is not without uncertainties. Category B suggests that animal studies have not demonstrated a risk to the fetus, and although well-controlled studies in pregnant women are lacking, the risk is considered remote based on available data.
The University of Toronto study and subsequent research indicate that Zofran does not significantly increase the risk of birth defects. However, these studies also emphasize that the sample sizes were limited, and absolute safety cannot be guaranteed. For example, the BioMed Research International study from 2013, which reviewed data from nearly 100,000 births, could not definitively conclude Zofran’s safety, highlighting the need for further research.
For pregnant women experiencing severe nausea, the decision to use Zofran should involve a detailed discussion with a healthcare provider. It’s crucial to evaluate the severity of the symptoms and consider alternative treatments, such as dietary changes or other safer anti-nausea medications. While Zofran appears to be a relatively safe option, its use should be carefully considered, keeping in mind that no medication is entirely risk-free during pregnancy.
Conclusion
What should pregnant women suffering from severe nausea take away from these studies on the safety of Zofran during pregnancy? First, and remember that I am not a medical professional but rather a researcher, Zofran appears to be safer during pregnancy. However, although the drug appears to be safe, there is not yet evidence that the drug is safe. As I told my fellow blogger, a pregnant woman should work with her health care provider to evaluate the risks and benefits of using the medication while pregnant.
The decision to use any medication during pregnancy, including Zofran, should be made with a clear understanding of the risks and benefits, prioritizing the health and well-being of both the mother and the baby.
Disclaimer: The information provided in this article is not meant to replace the professional medical advice from a health care professional.
References
Drugs Used in Pregnancy (Part 1 of 2). 2013. Monthly Prescribing Reference 29(10). 221-222.
Hale, Thomas W. 2012. Medications and mothers’ milk, 15th edn. Amarillo, Texas: Hale Publishing.
Off-label use of ondansetron in pregnancy in Western Australia: http://www.hindawi.com/journals/bmri/2013/909860/abs/
Ondansetron in pregnancy and risk of adverse fetal outcomes: http://www.ncbi.nlm.nih.gov/pubmed/23445092
The safety of ondansetron for nausea and vomiting of pregnancy: a prospective comparative study: http://onlinelibrary.wiley.com/doi/10.1111/j.1471-0528.2004.00236.x/full