Pregnancy and cervical infection with human papillomaviruses

Objective: This investigation was undertaken to assess whether pregnancy represents a risk factor for human papillomavirus (HPV) infection which is independent of age and other known HPV risk factors. Methods: One hundred eighty-nine women were enrolled from the outpatient clinics of a large municipal hospital. The subjects completed a self-administered questionnaire and underwent a gynecologic examination which included a cervicovaginal lavage. Lavage samples were assessed for the presence of HPV DNA by restriction enzyme analysis and Southern blot hybridization. Statistical significance was assessed by the χ²-test. Logistic regression was used to assess the association between pregnancy and HPV while controlling for the effect of other risk factors. Results: The prevalence odds ratio (POR) for the association of pregnancy and HPV infection was 2.2 (95% C.I. 1.1-4.5). The prevalence of HPV increased with increasing gestational age (HPV prevalence of 18.9% among non-pregnant women vs. 27.3% in those in the first 12 weeks of pregnancy and 39.7% in those who were past the 12th week of pregnancy). Although statistical significance was not achieved in a multivariate model which controlled for age, race/ethnicity, education, age at first coitus, number of sexual partners within the last year and parity, the POR associated with the current pregnancy (POR = 2.1) was not substantially changed by correcting for these risk factors, suggesting that these factors were not significant confounders of the association between pregnancy and HPV infection. Conclusion: Current pregnancy is associated with a modestly increased prevalence of cervical HPV infection. This association appears to be independent of age and other major HPV risk factors.