HPV viral load determination during pregnancy as a possible cervical cancer risk

Pregnancy may be a risk factor for cervical human papillomavirus (HPV) infection due to associated increased hormonal level and immunosuppression. Although a majority of such infections are transient, persistent infection may lead to premalignant/malignant cervical lesion. The viral burden is thought to be an indicator for persistence of the infection and malignant transformation. To assess pregnancy as a risk factor for cervical HPV infection, we compared HPV prevalence and viral load among 25 pregnant women to those of 24 non-pregnant and 28 cervical cancer cases. HPV DNA was detected in the cervical cells by PCR using MY09/MY11 primers. HPV positive cases were retested with a low stringency PCR method to ascertain the viral load. HPV prevalences of 68%, 25% and 89% were observed among pregnant women, non-pregnant women and in the cervical cancer cases, respectively. High viral load was frequently (40%) observed in cervical cancer patients. Median viral copy number/cell did not vary much between the non-pregnant and pregnant women. However, pregnant women had a predominantly moderate viral load whereas the low viral load was more frequent in non-pregnant women. High viral load was found to be associated with the presence of HPV 16 in the cervical cancer cases as compared to pregnant/non-pregnant HPV infected women.