The association between pregnancy and human papilloma virus prevalence.

This study examined the effects of pregnancy on the prevalence of HPV infection, comparing 69 pregnant and 54 nonpregnant age-frequency matched female patients. HPV prevalence was detected by DNA hybridization using the ViraPap/ViraType dot blot procedure. The prevalence of HPV among pregnant women increased with gestational age from 8.0% in the first trimester, to 16.7% in the second, and 23.1% in the third trimester. This finding suggests that HPV infection may be activated by hormonal or other effects of pregnancy and may explain why number of pregnancies is known to be associated with increased risk of cervical dysplasia and cancer. Oncogenic HPV types 16/18 and 31/33/35 were identified with almost equal frequency in the study population whereas HPV 6/11 was seen rarely. The logistic regression models indicate that there were no significant differences between HPV positive and HPV negative groups by age, income, number of sex partners, age of first intercourse, average frequency of intercourse per month, number of pregnancies, oral contraceptive duration, or pregnancy status. There were no interaction effects. A current Pap result of cervical dysplasia (OR = 8.9; 95% confidence interval: 2.1, 38.8), oral contraceptive use (OR = 0.1; 0.03, 0.6), and education (OR = 1.4; 1.1, 1.8) were significant predictors of HPV status.