Effects on cycle control and bodyweight of the combined contraceptive ring, NuvaRing, versus an oral contraceptive containing 30 microg ethinyl estradiol and 3 mg drospirenone.

The objective of this study was to compare cycle control, cycle-related characteristics and bodyweight effects of NuvaRing with those of a combined oral contraceptive (COC) containing 30 microg of ethinyl estradiol and 3 mg of drospirenone. A randomized, multicentre, open-label trial in which 983 women were treated (intent-to-treat population) with NuvaRing or the COC for 13 cycles. Breakthrough bleeding or spotting during cycles 2-13 was in general less frequent with NuvaRing than that with the COC (4.7-10.4%) and showed a statistically significant odds ratio of 0.61 (95% confidence interval: 0.46, 0.80) with longitudinal analysis. Intended bleeding was significantly better for all cycles with NuvaRing (55.2-68.5%) than that with the COC (35.6-56.6%) (P < 0.01). Changes from baseline in mean bodyweight and body composition parameters were relatively small for both groups with no notable between-group differences. NuvaRing was associated with better cycle control than the COC, and there was no clinically relevant difference between the two groups in bodyweight.