Increased impact of a contraceptive vaginal ring with ethinyl estradiol and nestorone on C-reactive protein.

UNLABELLED

OBJECTIVE & STUDY DESIGN: In a parallel design, 23 and 22 healthy pre-menopausal women were randomly administered a contraceptive vaginal ring (CVR) delivering 150/15 μg Nestorone®/ethinyl estradiol (EE) daily or an oral contraceptive (OC) containing levonorgestrel and EE (150/30 μg) for three cycles, to compare the effects on C-reactive protein and other markers of inflammation. ANCOVA was performed with baseline values as covariate.

RESULTS

The CVR caused [estimate of difference (95% CI), 109% (16-275%)] higher levels of CRP than the OC, while no difference was observed for leukocyte 1% (-13/+17%) and monocyte counts 6% (-9/+23%). The greater increase in CRP was confined to CVR recipients exhibiting low pre-treatment CRP-levels, whereas no difference was observed in the increases for recipients in the highest tertile of pre-treatment CRP levels.

CONCLUSION

The difference in CRP rise in CVR and OC users does not correspond with the effects on other markers of inflammation and is most likely due to a specific difference in the effect of ethinyl-estradiol combined with nestorone in cases with low CRP.