Pregnancy and cervical infection with human papillomaviruses

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.

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 gynecological 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 chi 2-test. Logistic regression was used to assess the association between pregnancy and HPV while controlling for the effect of other risk factors.

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.

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.