Can HPV Pass from Mother to Baby During Pregnancy? How Is HPV Transmitted and Can It Be Prevented?

The Importance of HPV Infections

Human papillomavirus (HPV)is a viral infection transmitted sexually and through skin contact, affecting more than approximately 14 million people annually in the United States alone. Nearly half of HPV infections involve the genital area, and approximately 80 percent of sexually active people acquire HPV at some point and can spread it. HPV is not a single virus: approximately 200 types exist, and 30-40 infect humans.

• HPV types 16, 18, 31, 33, 45, 52 and 58 are known to cause cervical, vulvar, vaginal, anal and head and neck cancers;
• HPV types 6, 11, 16, 18, 31, 33, 45, 52 and 58 cause precancerous and dysplastic lesions;
• HPV types 6 and 11 cause genital warts.

- Related Topic: What Is a Virus? A Brief History of Viruses and Cancer-Causing Viruses

Can HPV Pass from Mother to Baby?

Maternal-to-child transmission of human papillomavirus (HPV) during pregnancy remains highly debated, particularly its timing, direction and magnitude. An infected mother can transmit HPV to her baby during pregnancy and delivery. The prospective study discussed here examines direct transmission risk at different pregnancy stages.

Study Method

In South Korea, cervical samples were collected throughout pregnancy and after delivery from 153 healthy pregnant women with no previously detected HPV infection. Cord blood, newborn nasopharyngeal swabs and placental biopsy samples were collected at birth. Using the GG HPV Genotyping Chip Kit, DNA isolation, polymerase chain reaction and hybridization were performed. Neonatal HPV detection was defined as HPV DNA present in both cord blood and newborn nasopharyngeal swabs.

Results

• During the first trimester (0-3 months), %14 of healthy women (22/153) tested positive for HPV DNA; during the second trimester (3-6 months), %18 (22/124), and during the third (6-9 months), %10 (15/153).
• At any stage of pregnancy, %24 of women (37/153) tested positive for HPV DNA.
• At birth, %5.2 of newborns (8/153) were HPV DNA-positive. Seven of these eight babies had HPV-positive mothers.
• Placental HPV DNA was positive in % 3.3 of cases (5/152), all five from mothers with at least one positive HPV test. Neonatal HPV DNA detection was associated with maternal HPV detection at any pregnancy stage.
• Among 153 newborns, 145 had no HPV; of the 8 infected newborns, 5 were boys and 3 girls.
• Smoking, alcohol and age did not significantly affect HPV infection.
• Of these 8 babies, 7 had HPV detected while still in the womb. Therefore, vaginal versus cesarean delivery made little difference. Indeed, of 8 infected newborns, 5 were delivered by cesarean.

Conclusion

The idea that genital HPV passes from mother to baby only through vaginal delivery contradicts these findings. HPV DNA was detected in %5.2 (8/153) of babies born to healthy women negative before pregnancy, associated with maternal infection at any pregnancy stage. Up to %80 of babies born to women with genital HPV may have detectable HPV DNA in nasopharyngeal and oral mucosa, persisting for months or years. HPV, with its potentially troubling consequences, should therefore be addressed through vaccination before sexual activity begins.

How Is HPV Transmitted?

One main concern is whether HPV is contagious; yes, it is. Contact with an infected person can transmit it. Sexual behavior substantially affects infection risk.

For example, multiple partners and frequent partner changes increase risk. Becoming sexually active at a young age also increases risk. Exposure to multiple HPV types can occur at different times or simultaneously.

Transmission Routes Include

• Vaginal, oral or anal sex with HPV-infected people.
• Touching infected people's genital areas.
• Mother to child during pregnancy or birth.
• Sharing sex toys.
• Sharing bath towels may spread infection in rare situations.
• HPV-contaminated hospital surfaces may transmit infection if improperly disinfected.
• Medical instruments may rarely carry HPV even after disinfection.
• Toilet seats. Research suggests the virus can spread from patients' genital areas to hands and toilets they use.

Sexual contact carries the greatest risk among these routes because exposure to body fluids is most intense then.

What Are the Symptoms of HPV Infection?

HPV causes no symptoms in most cases. Many people are infected without knowing it.

• Some develop genital warts on the penis, scrotum, labia, vagina, cervix or anus.
• They may appear as a single small genital bump or clusters of bumps.
• Warts may be small or large.
• They may be flat, raised or cauliflower-shaped. This type of HPV does not imply higher cancer risk.

In %90 of infected people, the immune system controls the infection within approximately 2 years. Cervical cancer risk after genital HPV infection is approximately %0.8.

How Can HPV Be Prevented?

• Condoms can help during sexual intercourse and are recommended, but do not protect uncovered areas.
• The best protection is receiving the HPV vaccine before sexual activity or HPV exposure.
• Choosing monogamy.
• Caution in special circumstances involving shared towels, underwear or toilets.

- Note: Vaccination during pregnancy is not recommended. If a woman discovers she was pregnant when vaccinated, the 2nd and 3rd doses should be postponed until after delivery. Pregnancy testing before starting vaccination is therefore unnecessary. However, there is no evidence of harmful effects or adverse events requiring intervention in pregnancies where HPV vaccination occurred.

How Is HPV Diagnosed?

HPV in women is diagnosed through one of the following:

• Pelvic examination for warts.
• Cervical Pap smear testing to look for early-stage/cancerous cells.
• Biopsy, removal of a tissue piece, from the cervix or other genital areas.

- Related Topics:

• What Does an Abnormal Pap Smear Result Mean?
• George Papanicolaou, Who Saved Millions of Women's Lives with the Pap Smear

How Is HPV Treated?

If the immune system cannot eliminate the virus, there is no cure for HPV infection. Warts can be treated or removed using chemicals, freezing, burning, lasers or surgery.

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