[Study of endometrial maturation under the influence of an oestrogen-progestin combination containing 30 mcg of EE and 150 mcg of desogestrel: the value of biopsy of the endometrium in assessing the efficacy of an oestrogen-progestin combination]

Endometrial biopsies were performed on 21 female volunteers aged 18-40 years to evaluate the inhibitory effects of a new contraceptive formulation and the influence of the steroid on 1 of the major target organs. The formulation contained 30 mcg of ethinyl estradiol and 150 mcg of the new progestin desogestrel. The 21 women had taken the OC for at least 3 months. The aspiration biopsies were performed during 3 different cycle phases in 3 different centers in Nice Bordeaux and Paris. 5 biopsies done during days 1-9 5 during days 10-17 and 7 during days 18-23 were retained. Results from the 17 biopsies were remarkably homogeneous for all cycle dates. The endometrium was constantly hypotrophic the glandular tubes were of small size and signs of glandular secretion were present in 16 of 17 cases with intracellular vacuoles and a visible secretion. Mitosis was observed in the glandular cellule in only 1 case. The stroma were edematous in 9 of 17 cases. The results demonstrated a low estrogenic stimulation and a dominant progestagenic action due to the strong antigonadotrophic and progestagenic properties of desogestrel. The advantages of the new generation of progestins such as desogestrel are obvious from the study. The study also demonstrates the need for endometrial biopsies to characterize the overall effects and climate of combined OCs since some of the most common markers can provide misleading results.