Is Valtrex Safe During Pregnancy

Status

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

Reason

Limited human pregnancy data. Use only if benefit outweighs risk; consult your OB/GYN or prescriber.

Drug Information

Brand Name
Valtrex
Generic Name
valacyclovir
Drug Class
antiviral (herpes virus DNA polymerase inhibitor)
FDA Category
N/A (PLLR narrative label)
Rx Status
prescription

Safe Amount

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

Effects

Pregnancy
Untreated genital herpes, especially late in pregnancy, can increase neonatal herpes risk. FDA notes risk is higher when HSV is acquired in late pregnancy.
Mother
May help treat or suppress herpes infections in pregnancy. Maternal toxicity is possible, especially with kidney problems or dehydration.
Baby
FDA labeling reports no identified drug-associated risk of major birth defects, but data are limited. Untreated herpes can also harm the newborn.

Trimester Notes

1st Trimester
No clear increase in major birth defects has been identified, but data are limited.
2nd Trimester
Limited data. Use only if needed and directed by your prescriber.
3rd Trimester
Late-pregnancy HSV infection can raise newborn infection risk. Provider may recommend suppressive treatment near delivery.

Risk-Benefit Note

For antivirals, the risk of untreated herpes must be weighed against limited pregnancy safety data. Do not stop or start without provider guidance.

Conditions & Warnings

  • Consult OB/GYN or prescriber
  • Do not stop or continue without provider review
  • Pregnancy registry data are limited
  • Herpes simplex infection in pregnancy
  • Kidney disease may raise side effects risk

Alternatives

  • Acyclovir, if your prescriber recommends it
  • Non-drug measures your OB/GYN recommends for herpes management

References

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