Is Zofran Safe During Pregnancy

Status

caution Last reviewed: 2026-05-16 · Confidence: moderate

Reason

Pregnancy data are limited and mixed. FDA says use only if clearly needed.

Drug Information

Brand Name
Zofran
Generic Name
ondansetron
Drug Class
antiemetic; serotonin 5-HT3 receptor antagonist
FDA Category
B
Rx Status
prescription

Safe Amount

Dosage must be determined by your provider based on individual risk/benefit.

Effects

Pregnancy
Should be used only when clearly needed during pregnancy; official labeling says human data are not adequate and well-controlled.
Mother
Can cause QT prolongation and, at higher doses, heart rhythm problems in the person taking it.
Baby
Limited data do not reliably show harm, but some studies reported small possible increases in cleft palate or heart defects; findings are inconsistent.

Trimester Notes

1st Trimester
Use caution. This is the main time for organ formation, and pregnancy data are limited and mixed.
2nd Trimester
Use only if needed. Human data remain limited; your prescriber should weigh benefit and risk.
3rd Trimester
Use only if needed and only with provider guidance; monitor for maternal heart rhythm issues if risk factors exist.

Risk-Benefit Note

If nausea or vomiting is severe, your provider may decide the benefit outweighs the risk. Do not stop or start it without medical advice.

Conditions & Warnings

  • Consult OB/GYN or prescriber
  • If you have heart rhythm problems, long QT syndrome, low potassium, or low magnesium, tell your prescriber
  • If you are taking other QT-prolonging medicines, tell your prescriber

Alternatives

  • doxylamine-pyridoxine (if appropriate and prescribed/available)
  • diet changes and small frequent meals
  • fluids and electrolyte replacement
  • talk to your OB/GYN about other anti-nausea options

References

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