Efeito da inserção de implante anticoncepcional contendo acetato de nomegestrol sobre a função ovariana, muco cervical e penetração espermática Effects of a contraceptive implant containing nomegestrol acetate on ovarian function, cervical mucus and sperm penetration

Abstract

OBJETIVOS: estudar o efeito de um único implante de acetato de nomegestrol (Uniplant) sobre função ovariana, produção do muco cervical e penetração espermática, quando inserido na fase pré-ovulatória. MÉTODOS: estudo clínico aberto, comparativo, incluindo 20 mulheres com ciclos menstruais regulares que foram estudadas durante um ciclo menstrual antes (controle) e um ciclo menstrual depois da inserção do implante. Dosagens de hormônio luteinizante (LH), estradiol e progesterona, ultra-sonografia vaginal, coleta de muco cervical e teste de penetração espermática foram realizados. Para comparação estatística, foi utilizado o Student t-test para grupos pareados e o teste Wilcoxon não paramétrico. Os valores estão mostrados como médias ± erro padrão. RESULTADOS: todos os ciclos controles foram ovulatórios com parâmetros normais. Os níveis pré-ovulatórios de estradiol e LH diminuíram significativamente de 603,2 ± 78,0 pmol/l e 22,5 ± 6,5 UI/l na pré-inserção do implante para 380,7 ± 51,9 pmol/l e 4,9 ± 1,3 UI/l 48 horas após a inserção (p OBJECTIVE: to study the effect of a single contraceptive implant of nomegestrol acetate (Uniplant) on the ovarian function, cervical mucus production and sperm penetration, when inserted in women in the preovulatory phase. METHODS: twenty women with regular menstrual cycles were included in an open comparative study. All participants were investigated during one menstrual cycle before (control) and one menstrual cycle after implant insertion. Measurements of estradiol, LH, and progesterone, as well as transvaginal sonography, cervical mucus examination and sperm penetration test, were carried out. Statistical analysis was performed with the paired t-test and the non-parametric test of Wilcoxon. RESULTS: all control cycles were ovulatory and presented normal parameters. Preovulatory estradiol and LH peak decreased significantly from 603.2 ± 78.0 pmo/l and 22.5 ± 6.5 IU/l at pre-insertion to 380.7 ± 51.9 pmol/l and 4.9 ± 1.3 IU/l 48 hours after implant insertion (p < 0.05 and p < 0.01, respectively). Progesterone levels did not vary significantly (control cycle = 49.8 ± 3.3 nmol/l and treated cycle = 43.2 ± 5.2 nmol/l). Cervical mucus and sperm penetration tests were profoundly affected in 10.5% of the users 20 h after implant insertion, in 68.5% after 24 h and in 100% after 48 h. Follicular rupture occurred in the majority of the cycles 48 h after implant insertion. CONCLUSIONS: the use of a single implant of nomegestrol acetate affected estradiol and LH preovulatory peaks and disrupted the process of cervical mucus production and sperm penetration, but it was unable to prevent ovulation when inserted at the preovulatory phase, which reinforces the need to insert the implant during the first five days of the menstrual cycle.

Keywords

• Implante contraceptivo
• Acetato de nomegestrol
• Uniplant
• Muco cervical
• Penetração espermática
• Contraceptive implant
• Nomegestrol acetate
• Uniplant
• Cervical mucus
• Sperm penetration