Perinatal transmission of vaginal HPV from pregnant women to placenta or infants infrequent: JAMA

A new study by Pranamika Khayargoli and team showed that pregnant women were commonly found to have vaginal human papillomavirus (HPV). However findings of this study were published in the Journal of American Medical Association.

Human papillomavirus infection during pregnancy is uncommon, and the risk of transfer to babies is unknown. As a result, the purpose of this study was to determine the prevalence of HPV in pregnant women, the risk of HPV detection in the placenta and in infants at birth, and the likelihood that HPV found at delivery will remain in neonates.

The Human Papillomavirus Perinatal Transmission and Risk of HPV Persistence in Children (HERITAGE) research enrolled participants between November 8, 2010, and October 16, 2016. On June 15, 2017, participant follow-up visits were completed. Participants were recruited from three academic hospitals in Montreal, Québec, Canada, and comprised pregnant women of at least 18 years of age and at 14 weeks or earlier of gestation. On November 15, 2022, the laboratory and statistical analyses were finished. HPV DNA testing on vaginal and placental samples taken by the patient. Conjunctival, pharyngeal, oral, and vaginal samples were taken from children of HPV-positive mothers for HPV DNA testing.

Vaginal HPV DNA testing was performed on self-collected vaginal samples acquired from pregnant women recruited during their first trimester and in the third trimester for those who had HPV-positive tests in the first trimester. All subjects had HPV DNA testing done on placental samples (swabs and biopsies) taken after delivery. Conjunctival, oral, pharyngeal, and genital samples were taken from children of HPV-positive mothers at birth, 3 months, and 6 months of age.

The key findings of this study were:

1. This research comprised 1050 pregnant women in total.

2. At the time of recruitment, the prevalence of HPV in pregnant women was 40.3%.

3. Among the 422 HPV-positive women, 280 (66.4%) had at least one high-risk genotype, whereas 190 (45.0%) had several genotypes.

4. HPV was found in 10.7% of placentas overall, although only 3.9% of samples on the fetal side under the amniotic membrane (14 of 361) were positive.

5. Overall, 7.2% of newborns had HPV, with the conjunctiva being the most common location of infection, followed by the mouth, vaginal region, and throat.

6. Importantly, all HPV found at birth in children is eliminated by the age of six months.

In this cohort research, pregnant women had a high incidence of vaginal HPV (40%) but a low prevalence of HPV in the placenta (10%). The presence of HPV in 3.9% of biopsies taken under the membrane of the fetal side of the placenta implies that, albeit rare, genuine placental infection is feasible. The findings imply that HPV can be found in newborns (7% in our research). Because HPV was not discovered regularly over time, data up to 6 months imply that the link with newborn health is likely limited.

Reference:

Khayargoli, P., Niyibizi, J., Mayrand, M.-H., Audibert, F., Monnier, P., Brassard, P., Laporte, L., Lacaille, J., Zahreddine, M., Bédard, M.-J., Girard, I., Francoeur, D., Carceller, A. M., … Mayrand, M.-H. (2023). Human Papillomavirus Transmission and Persistence in Pregnant Women and Neonates. In JAMA Pediatrics. American Medical Association (AMA). https://doi.org/10.1001/jamapediatrics.2023.1283