What is Human Papillomavirus (HPV) and how does it affect pregnancy?

Human Papillomavirus (HPV) and Its Effects on Pregnancy

HPV infection does not affect a woman's fertility or ability to carry a pregnancy to term, but certain treatments are contraindicated during pregnancy and genital warts may proliferate during pregnancy. 1

What is HPV?

Human papillomavirus (HPV) is the most common sexually transmitted viral infection worldwide. It is a small DNA virus that infects epithelial cells in various mucous membranes and skin surfaces. There are approximately 200 genotypes of HPV, with about 40 known to cause genital infections 2, 3.

HPV types are categorized as:

• High-risk types (16,18,31,33,35,39,45,51,52,56,58,59): Associated with cervical, anal, vaginal, vulvar, penile, and oropharyngeal cancers
• Low-risk types (6,11): Typically cause benign conditions like genital warts 3

Transmission

• Primarily through sexual contact (vaginal, anal, oral sex)
• Non-penetrative sexual activities involving skin-to-skin contact
• Vertical transmission from mother to child during childbirth (relatively rare)

HPV in Pregnancy

Prevalence and Infection Patterns

• Prevalence in pregnancy ranges from 5.5% to 65%, depending on age, geography, and gestational age 2
• HPV prevalence is twice as high in pregnancy compared to non-pregnant women 4
• Genital warts (caused by HPV types 6 and 11) tend to proliferate and become friable during pregnancy 1

Effects on Pregnancy Outcomes

Some studies have associated HPV infection with adverse pregnancy outcomes including:

• Spontaneous miscarriage
• Preterm birth
• Premature rupture of membranes
• Preeclampsia
• Fetal growth restriction
• Fetal death 2, 4

However, the evidence for these associations varies and is not conclusive.

Vertical Transmission and Neonatal Risks

• HPV types 6 and 11 can cause laryngeal papillomatosis among infants 1
• This condition is also known as juvenile-onset recurrent respiratory papillomatosis (JORRP) 2
• The route of transmission (transplacental, birth canal, or postnatal) is not completely understood 1
• Laryngeal papillomatosis has occurred even in infants delivered by cesarean section 1

Management of HPV During Pregnancy

Treatment Considerations

Contraindicated treatments during pregnancy:

• Podophyllin and podofilox 1
• Imiquimod and sinecatechins 1

Safe treatment options during pregnancy:

• Cryotherapy with liquid nitrogen
• Trichloroacetic acid (TCA) application
• Surgical or laser excision of warts 2

Delivery Considerations

• Cesarean delivery should NOT be performed solely to prevent transmission of HPV infection to the newborn 1
• The preventive value of cesarean delivery for laryngeal papillomatosis is unknown 1
• Cesarean delivery is indicated ONLY in cases where:
  1. Genital warts obstruct the pelvic outlet
  2. Vaginal delivery would result in excessive bleeding 1

Vaccination

• HPV vaccination is not currently recommended during pregnancy 2, 4
• However, studies on women inadvertently vaccinated during pregnancy have not shown adverse effects on either the fetus or mother 2
• Termination of pregnancy is not justified if vaccination occurs during pregnancy 4

Common Pitfalls and Caveats

1. Overestimating transmission risk: While vertical transmission is possible, it is relatively rare.

2. Unnecessary cesarean sections: Performing cesarean delivery solely to prevent HPV transmission is not recommended.

3. Using contraindicated medications: Always avoid podophyllin, podofilox, imiquimod, and sinecatechins during pregnancy.

4. Inadequate counseling: Pregnant women with genital warts should be counseled about the low risk of laryngeal papillomatosis in their infants.

5. Overlooking wart proliferation: Genital warts often grow faster during pregnancy and may require treatment if they become problematic.