The association between pregnancy and human papilloma virus prevalence.

Between October 1987-May 1988 researchers compared 69 pregnant patients with 54 age matched nonpregnant patients at the University of Iowa Medical School Hospital in Iowa City to examine the effects of pregnancy on the prevalence of human papilloma virus (HPV) infection. Almost all cases and controls were White. Pregnant women had more risks for cervical dysplasia and cancer than nonpregnant women: a simultaneous diagnosis of dysplasia/squamous intraepithelial lesions [odds ration(OR) 7.4] current and past smoking (p<.001 and p<.05) greater number of partners (p<.05) and pregnancies (p(.001) an earlier age at 1st intercourse (p<.001) a higher frequency of intercourse/month less education (OR 1.4) and poorer. In addition pregnant women tended not to use condoms (p<.01) which can prevent transmission of sexually transmitted diseases. Oral contraceptive (OC) use had a protective effect (OR 0.1) but duration of OC use did not significantly change the ORs. The 2 groups had basically the same overall frequency of HPV (15.9% pregnant and 14.8% nonpregnant) but HPV frequency increased as did gestational age. For example it was 8% for the 1st trimester 16.7% for the 2nd trimester and 23.1% for the 3rd trimester. This increase in frequency suggested that it occurs with activation of latent HPV infection or increased HPV plasmid replication during pregnancy. The researchers hypothesized that high progesterone levels may activate transcriptional HPV replication or change an immune response. Other studies demonstrated that increasing parity is linked with cervical cancer. Thus the researchers proposed that other researchers to set up longitudinal studies to follow pregnant and postpartum women to see if condylomas cervical dysplasia and cancer subsequently develop. These studies will allow researchers to determine if HPV status during the 2nd and 3rd trimesters predicts disease.