Contraception: The cervico—vaginal epithelium during 20 cycles' use of a combined contraceptive vaginal ring

The aim of the study was to evaluate the influence of a combined contraceptive vaginal ring (CCVR) made of Silastic® on the cervico-vaginal epithelium during 20 cycles of use. A total of 76 volunteers used the CCVR releasing 0.120 mg etonogestrel and 0.015 mg ethinyloestradiol daily. Cytological samples were taken of the vaginal epithelium, the ectocervix and the endocervix before the start, at 4 and 12 months, and at the end of the study. Cytology, hormonal profiles, human papilloma virus (HPV) status, DNA-flow cytometry, bacterial flora, and morpho-metry was performed on these samples. Colposcopy and histopathology of biopsy specimens were performed at the end. No cytological changes of the squamous epithelium or the columnar epithelium were found. HPV was detected in three samples of three different women. At least two of them reverted to HPV negative during the rest of the study period. Aneuploidy was diagnosed in 11 women before the study. Seven of them changed to diploid during the study. No changes from diploid to aneuploid were seen. Aneuploidy was not seen in any of the HPV positive samples. Although bacterial flora showed considerable variation during the study, no significant influence of the CCVR could be established. Morphometrical analysis showed an increasing nucleus:cytoplasm ratio of the squamous cells during the study. Mild dysplasia was detected in one woman at the end of the study. It was concluded that no unfavourable cytological or bacteriological changes of the cervico-vaginal epithelium were demonstrated during 20 cycles of CCVR use. The vaginal epithelium became more progestogenic during the study.