The combined contraceptive vaginal ring (NuvaRing) and endometrial histology.

We investigated the effects of NuvaRing on endometrial histology in a 2-year open-label, multicenter trial in 103 premenopausal women aged 18-35 years. Subjects received 26 cycles of treatment, each comprising 3 weeks of ring use followed by a 1-week ring-free period. Endometrial biopsies were taken at baseline, and at cycles 13 (month 12) and 26 (month 24). Normal biopsy results were obtained in all subjects after 24 months of NuvaRing treatment. Atrophic or inactive endometrium and secretory changes were present in the majority of the biopsies after 1 year and 2 years of treatment with the vaginal ring. It was concluded that long-term use of NuvaRing has no adverse effects on endometrial histology.