Prevalence of human papillomavirus infections in term pregnancy

The prevalence of human papillomavirus (HPV) infections in the lower genital tracts of pregnant and nonpregnant women was studied. Cervical and vaginal exfoliated cells were obtained during a routine pelvic examination in 45 pregnant women in early labor, and in 44 nonpregnant women. A detailed questionnaire with emphasis on sexual history and sexually transmitted diseases was administered. The two groups of women were comparable with respect to mean age, prior pregnancy experiences, and number of lifetime sexual partners. Compared with pregnant women, the nonpregnant women had a more frequent history of sexually transmitted diseases (61% versus 39%; p = 0.06), and of genital warts (16% versus 0%; p = 0.01). Utilizing Southern transfer and hybridization with 32P-labeled viral DNA probes for HPV types 6, 11, 16, 18, and 31, DNAs extracted from cervicovaginal exfoliated cells were assessed for HPV genomic sequences. HPV genomic sequences were identified in 25% of nonpregnant women compared with 13.5% of term pregnant women. This difference was not statistically significant (p = 0.26). Six HPV isolates identified in pregnant women were distributed as follows: type 6/11, 1; type 16, 1, type 31, 1; and unknown type, 3. Eleven isolates were identified in nonpregnant women and were distributed as follows: type 6/11, 2; type 16, 6; type 18, 2; and type 31, 1. HPV type 6/11, the type responsible for laryngeal papillomatosis of juvenile onset, was identified in 2% of the pregnant population and accounted for only one of six isolates. HPV DNA-positive pregnant and nonpregnant women were predominantly asymptomatic and had normal Papanicolaou smears and normal clinical examinations.