Effects on the endometrium, endo- and exocervix following the use of local progestogen-releasing delivery systems

Endometrial structural and inflammatory changes with exogenous progestogens

Safe and effective contraception is an international public health priority. The long-acting progestogen-only contraceptives are used by over 20 million women worldwide but their main drawback is abnormal uterine bleeding. Such bleeding arises owing to structural and inflammatory changes which compromise endometrial microvascular and epithelial integrity. The molecular and structural changes that lead to the vessel and surface epithelial fragility, and hence the side effect of abnormal uterine bleeding commonly seen with exogenous progestogen use, might be lessened by short-term treatments shown to shorten bleeding episodes.

Serum concentrations of estradiol, progesterone, and levonorgestrel are not determinants of endometrial histology or abnormal bleeding in long-term Norplant implant users

The objective of this study was to determine the relevance of serum estradiol, progesterone and levonorgestrel concentrations to endometrial histology and uterine bleeding associated with long-term Norplant implants use. Eighteen five-year users of Norplant implants had endometrial biopsies and determinations of serum estradiol, progesterone and levonorgestrel concentrations. Correlations among these factors and uterine bleeding were calculated. Proliferative endometrium (but not sex steroid levels) was associated with abnormal bleeding. Neither ovarian steroid nor levonorgestrel concentrations was a predictor of abnormal bleeding. Hyperplastic changes were not seen even with high estradiol and low levonorgestrel levels.