Sonographic assessment of ovarian and endometrial changes during long-term Norplant use and their correlation with hormonal levels

Abstract

Objective: To study the probability of ovulation and subclinical abortion during long-term use of Norplant and to assess the concomitant endometrial development.

Design: This was a prospective nonrandomized comparative study. The ovaries and endometrium were assessed daily by ultrasonography during 59 menstrual cycles in 50 women who were using Norplant for > 1 year. Serum concentrations of E2, P, FSH, LH, pregnancy specific beta 1 glycoprotein (Sp1), and hCG were also daily measured. The findings were compared with those in 35 ovulatory cycles in normal fertile women not using contraception.

Setting: Clients of the Family Planning Clinic of Assiut University Hospital (Norplant users) and the hospital women staff (controls).

Results: Sonographic and hormonal evidence of ovulation were observed in one third of Norplant users; two of them resulted in conception. However, the majority of these ovulatory cycles showed low midcycle peaks of E2, FSH, and LH and evidence of luteal phase defect (LPD). Excessive follicular enlargement was observed in 46% of the cycles. Norplant users had significantly thinner endometrium that did not exhibit the normal phasic changes in sonographic texture. Apart from conceptive cycles, no rise in Sp1 or hCG was observed.

Conclusions: Norplant acts mainly by inhibiting ovulation, but when this occurs, it is associated with LPD and subnormal endometrial development. Subclinical abortion does not contribute to the contraceptive effect.

PIP: 59 cycles in 50 women with Norplant inserted 18-48 months previously were observed daily with ultrasonic scanning and analysis of serum estradiol, progesterone, FSH, LH, pregnancy-specific beta1 one-glycoprotein (Spl) and hCG, compared to 38 menstrual cycles in matched controls not using contraception. Subjects were all parous, married clients at the Family Planning Clinic of Assiut University Hospital, Assiut, Egypt, or hospital staff controls. 35 of the 38 control cycles were ovulatory, and 3 conceptions were noted by ultrasonic and hormonal criteria. In Norplant users there were waves of folliculogenesis, some even occurring during vaginal bleeding. Estradiol levels were highest when the largest follicles were seen in anovulatory cycles, and lowest in quiescent cycles with no follicle development. This correlation was highly significant (p0.01).