Is Metformin Safe in Pregnancy

Status

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

Reason

Official sources do not show a clear birth-defect or miscarriage risk, but pregnancy use needs provider review.

Drug Information

Brand Name
Glucophage
Generic Name
metformin
Drug Class
Biguanide antihyperglycemic
FDA Category
B
Rx Status
prescription

Safe Amount

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

Effects

Pregnancy
Crosses the placenta. Use in pregnancy should be based on individual risk and benefit.
Mother
May help blood sugar control in diabetes. Poorly controlled diabetes itself raises pregnancy risks.
Baby
Limited data do not show a clear increase in birth defects or miscarriage. Some reports note smaller size at birth and uncertain long-term effects.

Trimester Notes

1st Trimester
No clear increase in major birth defects or miscarriage has been reported in official labeling, but data are limited.
2nd Trimester
Continue only if your prescriber says the benefit outweighs the risks and blood sugar control is needed.
3rd Trimester
No clear teratogenic signal, but fetal growth and later child outcomes have been studied less well. Provider review is recommended.

Risk-Benefit Note

Metformin may be continued in some pregnancies when blood sugar control benefit outweighs risk. Do not stop or start without your prescriber.

Conditions & Warnings

  • Consult OB/GYN or prescriber
  • Diabetes in pregnancy
  • Gestational diabetes
  • Polycystic ovary syndrome

Alternatives

  • Insulin
  • Lifestyle measures advised by your OB/GYN or diabetes clinician

References

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