ULTRASONOGRAPHIC MONITORING OF OVARIAN FOLLICLES IN WOMEN USING NORETHISTERONE FOR CONTRACEPTION

Objective: The purpose of this study was to examine the effect of intr anasal and oral norethisterone (NET) on ovarian folliculogenesis. Meth ods: Sixteen healthy, sterilized women with regular menstrual cycles w ere recruited to the study. NET 300 mu g per day was administered oral ly (n = 8) or intranasally (n = 8) for two consecutive menstrual cycle s. Serial pelvic ultrasonography was performed to monitor ovarian foll icular growth. Results: Ultrasonographic evidence of normal follicular growth and ovulation was observed in 10 cycles whilst 22 cycles were anovulatory. Formation of follicular cysts was seen in 14 cycles, 13 o f which were anovulatory and in one ovulation was observed in the oppo site ovary. The size of the cysts varied between 27 and 44 mm. The cys ts disappeared when NET treatment was discontinued. A positive correla tion between cyst size and estradiol levels was observed with intranas al NET in 50% of cyst cycles. In three cycles, although normal follicu lar growth and endocrine profile were observed, the follicles failed t o rupture. These were classified as luteinized unruptured follicles. I mmature follicles <10 mm were seen in six cycles. Conclusion: The stud y showed that NET administered either orally or intranasally evidently disturbs normal follicular growth and rupture.