A 2-year comparative study of endometrial histology and cervical cytology of contraceptive implant users in Birmingham, UK

Abstract

The objectives of this study were to evaluate the endometrial histology and cervical cytology of users of two contraceptive implants releasing etonogestrel/3-keto-desogestrel (Implanon) and levonorgestrel (Norplant) in West Midlands (UK) users. A 2-year prospective randomized design was used to study 60 implant users. Endometrial histology and cervical cytology were compared before insertion and after 12 and 24 months. At the end of 12 months, the majority of samples were inactive/weakly proliferative in both groups. At the end of 24 months, this remained unchanged in the Implanon group whereas the pattern was more diverse in the Norplant group. Endometrial thickness was significantly reduced in both groups during treatment. Cervical cytology remained unchanged. It is concluded that, after 2 years, there was no evidence of an increasing risk of endometrial hyperplasia, endometrial carcinoma, cervical intra-epithelial neoplasia or cervical carcinoma in either of the two groups of implant users.

PIP: Changes in endometrial histology and cervical cytology related to use of two contraceptive implants were investigated in a 2-year prospective study conducted at Birmingham (UK) Women's Hospital. 60 women with regular menstrual cycles were randomly assigned to receive either Implanon (etonogestrel/3-keto-desogestrel) or Norplant (levonorgestrel). After 12 months of implant use, most endometrial samples in both groups were inactive or only weakly proliferative. After 24 months, this pattern remained unchanged in the Implanon group. It was more diverse, however, in the Norplant group, where there was evidence of proliferative-phase endometrium. Endometrial thickness, assessed quarterly by transvaginal ultrasound scans, was significantly reduced in users of both implants. Cervical cytology remained unchanged from baseline to 24 months. These findings suggest that users of both implant systems are not at increased risk of endometrial hyperplasia, endometrial carcinoma, cervical intra-epithelial neoplasia, or cervical carcinoma.