Study of ovarian function in amenorrheic users of Mirena®
I.C. Barbosa, H. Maia Jr, A. Botto, R. Lopes, A.C.V. Lopes
Department of Gynecology, Obstetrics and Human Reproduction, Federal
University of Bahia, Salvador, Bahia, Brazil
Objectives: The objective of this study was to evaluate changes in
ovarian activity and in cervical mucus in amenorrheic users of Mirena®.
Material & Methods: Twenty amenorrheic patients, who had been
using Mirena® for three years, were studied during 60 days. Ultrasonography,
blood sampling for hormone measurement of estradiol, progesterone and LH, as
well as cervical mucus collection, were carried out twice weekly during 60 days.
Results: Fifty-two percent of women presented progesterone peaks
>15.0 nmol/l, and follicular activity as assessed by vaginal sonography. Of
these women, 25% presented persistent follicular cysts mm (mean maximum
diameter=35.4+1.7 mm). These follicular cysts disappeared spontaneously
within a maximum of 55 days. Twenty-seven percent of women presented follicular
development and normal follicular rupture with progesterone levels >15.0 nmol/l.
Forty-eight percent of women presented no follicular development and no luteinic
activity according to progesterone levels and vaginal sonography. All twenty
women had sparse, viscous cervical mucus and the material collected was
insufficient for analysis.
Conclusions: These results confirm previous findings that the most
important mechanism of action of Mirena® is the local effect it exerts on the
endometrium and on cervical mucus. This study also confirms that the majority of
patients in amenorrhea have ovulatory cycles. The physical and chemical changes
in the characteristics of the cervical mucus of amenorrheic patients result in
the high efficacy rate of Mirena® as a contraceptive method.