Morphometric studies of the endometrium, the Fallopian tube and the corpus luteum during contraception with the 300 μg norethisterone (NET) minipill

Abstract

Biopsy specimen from endometrium, Fallopian tube and corpus luteum were obtained from 35 women treated with 300 μg norethisterone daily and from 10 untreated, normally menstruating women. Peripheral levels of LH, progesterone and estradiol were measured. In the norethisterone-treated women four different ovarian reactions were identified. Ovarian activity was completely suppressed (Type A) in 3 women, follicular activity only (Type B) in 10 women, follicular activity was followed by insufficient luteal function (Type C) in 12 women, and peripheral estradiol and progesterone levels compatible with normal ovulation (Type D) in 10 women. The histology of the endometrium varied between atrophy (3 subjects), suppressed proliferation (9 subjects), proliferation (8 subjects), irregular secretory changes (12 subjects) and apparently normal secretory activity (3 subjects). When the histology of endometrium and Fallopian tube was compared with the peripheral hormonal levels and the corpus luteum steroid production in vitro, no correlation was found. Nor was a correlation found between the histologic changes of corpus luteum, endometrium and Fallopian tube. Thus, these target organs seem to react independently to norethisterone treatment.