Latent human papillomavirus infection in pregnant women at term: a case-control study.

Cervicovaginal lavages from 752 pregnant women at term were investigated by polymerase chain reaction to evaluate human papillomavirus (HPV) infection prevalences and were compared with cervicovaginal samples from two series of nonpregnant subjects (504 healthy women attending a family planning service and 560 symptomatic patients attending a vaginitis outpatient service). The odds ratios (ORs) of HPV infection were computed by conditional logistic regression analysis on age-matched sets. In pregnant women, the overall risk of HPV infection was about the same as in nonpregnant healthy subjects (adjusted OR, 0.90; 95% confidence interval [CI], 0.51-1.58) and was 50% less than in patients with symptomatic vaginitis (adjusted OR, 0.48; 95% CI, 0.30-0.76). Moreover, the prevalence of oncogenic HPV types 16 or 18 (or both) was lower in pregnant women (P = .015 and P = .0018 respectively).