Objective: To evaluate the risk of perinatal human papillomavirus (HPV) transmission from mothers with latent infections to the oropharyngeal mucosae of their infants.
Methods: Seven hundred eleven mother-newborn pairs were tested. Polymerase chain reaction was done with MY09/MY11 consensus primers to identify HPV DNA in maternal cervicovaginal lavages and newborn nasopharyngeal aspirates. Positive cases were further amplified with type-specific primers for HPVs 6, 11, 16, 18, and 33. All infants born to HPV-positive mothers were observed to 18 months for appearance of HPV in oropharyngeal mucosae.
Results: Human papillomavirus DNA was detected in 11 neonates born vaginally to HPV-positive women, a vertical transmission rate was 30% (95% confidence interval [CI] 15.9, 47). Nasopharyngeal aspirates were HPV-negative in all 11 cases in which rupture of membranes occurred less than 2 hours before delivery. When rupture preceeded delivery by 2-4 hours, and when it occurred after more than 4 hours, the respective rates for HPV positivity were seven of 21 and four of five (chi2 for trend = 10.7, P = .001). At follow-up, virus was cleared from the oropharyngeal samples as early as the 5th week.
Conclusion: Pregnant women with latent HPV infections have low potential of transmitting the virus to the oropharyngeal mucosae of their infants. The time between rupture of the amnion and delivery seems to be a critical factor in predicting transmission. Human papillomavirus-positive infants should be considered contaminated rather than infected since virus is cleared over several months after birth.