Are Human Papillomavirus (HPV) vaccines safe to administer during pregnancy?

HPV Vaccines in Pregnancy

HPV vaccination should be delayed until after pregnancy completion, as recommended by multiple guidelines and the FDA drug label. 1, 2, 3

Safety Considerations

• HPV vaccines are not recommended during pregnancy due to limited safety data, although available evidence does not suggest increased risks of adverse pregnancy outcomes 1, 3
• If a woman becomes pregnant after starting the HPV vaccination series, the remaining doses should be postponed until after delivery 1, 3
• If a dose of HPV vaccine is inadvertently administered during pregnancy, no specific intervention is needed 1, 3
• Women who are breastfeeding can safely receive the HPV vaccine without restrictions 1, 3

Evidence on Pregnancy Outcomes

• The FDA drug label for Gardasil-9 (HPV vaccine) reports that in pre-licensure studies, pregnancy outcomes among those inadvertently vaccinated early in pregnancy did not suggest increased risks 3
• A five-year pregnancy registry that enrolled 2,942 women inadvertently exposed to HPV vaccine during pregnancy found rates of miscarriage (6.8%) and major birth defects (2.4%) consistent with background rates in the general population 3
• Post-marketing studies conducted in the U.S. and Nordic countries did not suggest increased risks with HPV vaccination during pregnancy 3
• A 2023 meta-analysis found no significant increase in risk of miscarriage (RR=2.01; 95% CI: 0.66-6.13) or stillbirth (RR=2.02; 95% CI: 0.65-6.27) among women vaccinated against HPV during pregnancy 4
• A 2021 study of 1,493 pregnancies found that 9-valent HPV vaccine exposure during pregnancy was not associated with increased risk for spontaneous abortion (hazard ratio, 1.12; 95% CI, 0.66-1.93) compared with distal vaccine exposures 5

Pregnancy Registry

• A pregnancy registry has been established to monitor outcomes in women exposed to HPV vaccine during pregnancy 3
• Healthcare providers should report any HPV vaccine exposures during pregnancy to the registry at 1-800-986-8999 1, 3

Special Populations

• Immunocompromised individuals can receive HPV vaccine as it is a non-infectious vaccine, though immune response may be diminished 1, 3
• The vaccine has not been evaluated in adults over 45 years of age 3

Common Pitfalls and Caveats

• Pregnancy testing is not required before HPV vaccination, but vaccination should be delayed if pregnancy is known 3
• If pregnancy is discovered after vaccination has begun, termination of pregnancy is not justified based on HPV vaccination exposure 6
• The optimal time for HPV vaccination remains before potential exposure to HPV through sexual contact, typically at ages 11-12 years 7
• Some researchers have proposed considering HPV vaccination during pregnancy in the future to improve vaccine uptake rates, but this approach is not currently recommended by guidelines 8

Algorithm for Managing HPV Vaccination and Pregnancy

1. For women planning pregnancy:

   • Complete HPV vaccination series before conception if possible 1, 2
   • If vaccination series is started but not completed, finish remaining doses before pregnancy 1

2. For pregnant women:

   • Defer starting or continuing HPV vaccination until after pregnancy 1, 3
   • If HPV vaccine was inadvertently administered during pregnancy:
     • No intervention is needed 1
     • Report to the pregnancy registry (1-800-986-8999) 1, 3
     • Continue prenatal care as usual 3

3. For postpartum women:

   • HPV vaccination can be safely administered to breastfeeding women 1, 3
   • Complete any previously started vaccination series 7
   • Consider initiating vaccination if not previously vaccinated and under age 26 (or up to age 45 with shared clinical decision-making) 2, 7