Study on the effects of a single implant containing nomegestrol acetate (UNIPLANT) on the hormonal profile, endometrial morphology and ultrasonographic evaluation of ovarian function

I.C. Barbosa, H. Maia Jr, R. Lopes, A.C.V. Lopes, E.M. Coutinho

Department of Gynecology, Obstetrics and Human Reproduction, Federal University of Bahia, Salvador, Bahia, Brazil

Objectives: The objective of this study was to evaluate the effects of a single silastic implant containing 55 mg+10% of nomegestrol acetate on the hormonal profile, endometrial morphology, cervical mucus, maturation index and evaluation of ovarian function by vaginal sonography, during one year.

Material & Methods: Twenty healthy women of reproductive age (18–30 years old) participated in this study. Prior to implant insertion, a clinical examination was carried out, which included: a general medical and gynecological examination, as well as the collection of cervical/vaginal material for cytology and maturation index. Hysteroscopy with endometrial biopsy was carried out during the control cycle in all patients. All patients were submitted to a second hysteroscopy during the study, five during the second month of use, five during the sixth month and ten during the twelfth month of UNIPLANT use. In the same cycle in which hysteroscopy was performed, hormone measurement, vaginal sonography and cervical mucus collection was carried out thrice weekly.

Results: Based on levels of plasma progesterone, 80% of cycles studied in users of UNIPLANT were anovulatory. In 56% of cycles, the presence of persistent, non-luteinized follicles was observed. Cervical mucus was evaluated according to criteria established by the World Health Organization and showed a marked reduction during treatment cycles in all parameters studied. Endometrial thickness was <8 mm in all treated cycles in the study. Alterations in the endometrial architecture were observed in the majority of treated cycles and consisted of the presence of a thin endometrium with a marked increase in vascularization.

Conclusion: This study demonstrates that UNIPLANT is a long-acting contraceptive method that probably functions at hypothalamic-hypophyseal level, on the ovary, the endometrium and in cervical mucus production.