Return of ovarian function and endometrial morphology in women treated with norethisterone oenanthate: a pilot study

A comparative pilot study was undertaken in three centers to determine the time of return of ovulation after the injection of the steroidal contraceptive norethisterone oenanthate (NET-OEN). The effect of the compound on the endometrium and some properties of cervical mucus were also assessed. Increases in plasma progesterone levels suggested that ovulation resumed in all six women in Bahia within 60 days of injection of NET-OEN, whereas in Bangkok and New Delhi only two women in each center ovulated within this time. The difference in the time of return of ovulation between women in Bahia (mean time 42 days) and those in Bangkok and New Delhi (92.5 days) was statistically significant. Follicular function returned earlier than luteal function: all six women in Bahia and Bangkok and five of the six in New Delhi showed evidence of follicular activity within 60 days. All endometrial biopsies, obtained at a time of increased progesterone production, were secretory and suggested that administration of the gestagen did not exert a prolonged suppression of endometrial activity. In general, changes in cervical mucus were consistent with variations in plasma steroid levels.