title: The efficacy and acceptability of a low-dose levonorgestrel intravaginal ring for contraception in a UK cohort.
abstract: The efficacy and acceptability of a levonorgestrel-releasing intravaginal ring (IVR) for contraception was assessed in a British cohort studied as part of a multicentre, multinational clinical trial performed under the auspices of the World Health Organisation. One-hundred-and-fifty women took part in the study in two UK centres and completed 1417.5 months of method use. Fifty-nine women discontinued use of the IVR before the end of one year giving an overall discontinuation rate of 39.9 per 100 woman-years. The discontinuation for pregnancy with the ring in situ, was 3.0 per 100 woman-years (life table analysis). Menstrual disturbance, vaginal problems and involuntary expulsion resulted in discontinuation rates of 8.9, 8.4 and 1.6 per 100 woman-years, respectively. This method is an acceptable and effective method of contraception for women.
authors.affiliation: Institute of Obstetrics and Gynaecology, University of London, Hammersmith Hospital.
authors.forename: M G
authors.initials: MG
authors.lastname: Elder
authors.forename: J P
authors.initials: JP
authors.lastname: Lawson
authors.forename: M
authors.initials: M
authors.lastname: Elstein
authors.forename: I D
authors.initials: ID
authors.lastname: Nuttall
mesh_terms: D000293:Adolescent; D000328:Adult; D015331:Cohort Studies; D004305:Dose-Response Relationship, Drug; D005260:Female; D005298:Fertility / Q000187:drug effects; D006801:Humans; D007391:International Cooperation; D007433:Intrauterine Device Expulsion; D007436:Intrauterine Devices, Medicated; D016912:Levonorgestrel; D008599:Menstruation Disturbances / Q000139:chemically induced; D009644:Norgestrel / Q000008:administration & dosage* / Q000009:adverse effects / Q000494:pharmacology; D006113:United Kingdom; D014944:World Health Organization
chemical_list: D009644:Norgestrel; D016912:Levonorgestrel