HPV prevalence in cytomorphologically normal cervical scrapes of pregnant women as determined by PCR: the age-related pattern.

Diverging data exist on human papillomavirus (HPV) prevalence in cytomorphologically normal scrapes during pregnancy. The prevalence of HPV was therefore investigated by polymerase chain reaction method (PCR) in cytomorphologically normal scrapes of 709 pregnant women and 3,948 non-pregnant women visiting the same hospital during the same time period. The prevalence of all types of HPV among pregnant women was 9.6% (68/709) and the high risk HPV types of 16 and 18 were found in 3.1% (22/709). In the non-pregnant women the prevalence of all types of HPV was 10.9% (432/3,948) with 2.9% (116/3,948) HPV types 16 and 18. The highest prevalence of HPV was present in women at younger ages in both groups. With increasing age the prevalence declines from about 19% (15-25 yrs) to 5% (40-49 yrs). The age-adjusted odds ratio of prevalence of all types of HPV in pregnant versus non-pregnant women was 0.73 (95% CI 0.56-0.96, P = 0.025) and statistically significant. When HPV types 16 and 18 were considered, significant differences were not found. HPV of all types and types 16/18 prevalence was higher in the second half of pregnancy than in the first part but did not reach statistical significance. High HPV copy numbers in the scrapes were found during the first half of the pregnancy and not during the second half using a semi-quantitative HPV 16/18 PCR detection method. Since the difference in HPV prevalence between non-pregnant and pregnant women is very small, it is concluded that HPV prevalence in cytomorphologically normal smears is hardly influenced by pregnancy.