title: Steroidal contraceptive vaginal rings.
abstract: The development of steroid-releasing vaginal rings over the past three decades is reviewed to illustrate the role of this device as an effective hormonal contraceptive for women. Vaginal rings are made of polysiloxane rubber or ethylene-vinyl-acetate copolymer with an outer diameter of 54-60 mm and a cross-sectional diameter of 4-9.5 mm and contain progestogen only or a combination of progestogen and oestrogen. The soft flexible combined ring is inserted in the vagina for three weeks and removed for seven days to allow withdrawal bleeding. Progesterone/progestogen-only rings are kept in for varying periods and replaced without a ring-free period. Rings are in various stages of research and development but a few, such as NuvaRing, have reached the market in some countries. Women find this method easy to use, effective, well tolerated and acceptable with no serious side-effects. Though the contraceptive efficacy of these vaginal rings is high, acceptability is yet to be established.
authors.affiliation: Department of Reproductive Biology, All India Institute of Medical Sciences, Ansari Nagar, New Dehli, India.
authors.forename: N N
authors.initials: NN
authors.lastname: Sarkar
mesh_terms: D003274:Contraceptive Devices, Female; D017135:Desogestrel; D004967:Estrogens / Q000008:administration & dosage; D005260:Female; D006801:Humans; D008597:Menstrual Cycle; D009653:Norprogesterones / Q000008:administration & dosage; D017060:Patient Satisfaction; D011374:Progesterone / Q000008:administration & dosage; D011372:Progestins / Q000008:administration & dosage; D011379:Prognosis; D013256:Steroids / Q000008:administration & dosage*; D014753:Vinyl Compounds / Q000008:administration & dosage
chemical_list: D004967:Estrogens; D009653:Norprogesterones; D011372:Progestins; D013256:Steroids; D014753:Vinyl Compounds; C044815:etonogestrel; D011374:Progesterone; C029167:ST 1435; D017135:Desogestrel