Initial UK experience of the levonorgestrel-releasing contraceptive intravaginal ring

A study was performed to establish the tolerance, acceptability and associa ted efficacy of a levonorgestrel-releasing intravaginal ring (IVR) in a sam ple of British women requiring contraception. This was achieved with an ope n non-randomized prospective study of 1710 women aged 18-40 years, recruite d in 75 centers geographically spread around the UK using an IVR designed t o release 20 mug/day of levonorgestrel. Assessments were made at baseline, after 6 weeks, after 3 months and then 3-monthly. After initial insertion o f the IVR, it was changed at 3-monthly intervals. A total of 1591 women wer e eligible for analysis, with 572 available after 12 months and 34 after 24 months of use. Life-table analysis revealed pregnancy rates of 5.1% and 6. 5% at 12 months and 24 months, respectively. The IVR was rated as acceptabl e or very acceptable as a form of contraceptive by 60.7% of women at 12 mon ths. The most common adverse events were menstrual disturbance, headache an d vaginal discharge. No significant pattern of biochemical, hematological, microbiological or cytological abnormalities was found but vaginal erythema tous lesions were noted at some centers. This IVR was found to be a general ly well-accepted method of contraception with a failure rate comparable to some other progestogen-only methods. On this basis, further development of hormone-releasing intravaginal rings is justified.