NOMAC-E2 shows a better contraceptive effectiveness than LNG combined oral contraceptives in women under 25: real-world PRO-E2 study

Abstract

Objective: To investigate unintended pregnancy and changes in mood, acne, and weight in NOMAC-E2 vs levonorgestrel-containing COC (COCLNG) users under 25 years. Methods: In this large, observational study, new users (first-ever users of an eligible COC or restarting with the same or a new eligible COC after a break of at least 2 months) of NOMAC-E2 and COCLNG were recruited in 12 countries in Europe, Australia, and Latin America and followed up via questionnaires for up to 2 years. Unintended pregnancy was expressed by the Pearl Index (PI; contraceptive failures/100 women-years). Crude (HRcrude) and adjusted hazard ratios (HRadj) were calculated. Mood and acne changes were defined as change of score from baseline. Weight change was defined as percent change of body weight. Results: Overall, 12,829 NOMAC-E2 users and 17,095 COCLNG users under 25 were followed-up. The risk of unintended pregnancy was statistically significantly lower in the NOMAC-E2 cohort; confirmed events: 30 NOMAC-E2 (PI 0.24; 95% CI, 0.16–0.35) vs 94 COCLNG (PI 0.51; 95% CI, 0.41–0.62). The HRcrude for unintended pregnancy comparing NOMAC-E2 to COCLNG was 0.47 (95% CI, 0.31–0.71) and the HRadj was 0.52 (95% CI, 0.34–0.78). No differential effect on acne, mood, and weight was observed between cohorts. Conclusions: NOMAC-E2 shows a significantly better contraceptive effectiveness in young women and has no differential effect on acne, mood, and weight compared to COCLNG.