title: Contraceptive vaginal ring effectiveness is maintained during 6 weeks of use: a prospective study of normal BMI and obese women.
abstract: BACKGROUND
  A single study shows that contraceptive vaginal ring (CVR) use for up to 35 days in women with a normal body mass index (BMI) maintains serum hormone levels sufficient to suppress ovulation. This study is intended to confirm those results and to evaluate prolonged CVR use up to 42 days in both normal BMI and obese women.
  
  
  METHODS
  Twenty women with a normal BMI and 20 obese women enrolled in a prospective open label clinical study of ethinyl estradiol (EE) and etonogestrel (ENG) pharmacokinetics during six weeks of use of a single CVR. Participants underwent twice-weekly evaluations to determine serum hormone concentrations, ovarian follicle development, endometrial thickness and bleeding patterns.
  
  
  RESULTS
  Thirty-seven women completed follow-up including eighteen women with a normal BMI and nineteen obese women. EE and ENG concentrations remained in therapeutic range for all women. Follicular development and endometrial proliferation were minimal. By the sixth week, 30% of participants reported spotting or bleeding.
  
  
  CONCLUSIONS
  A single CVR used for 6 weeks demonstrates therapeutic serum levels of EE and ENG among women with normal and obese BMI. Women who forget to remove the CVR at day 21 may well have continued contraceptive protection during the next 3 weeks.
authors: Department of Obstetrics and Gynecology, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
authors: Monica
authors: M
authors: Dragoman
authors: Kelsey
authors: K
authors: Petrie
authors: Anupama
authors: A
authors: Torgal
authors: Tiffany
authors: T
authors: Thomas
authors: Serge
authors: S
authors: Cremers
authors: Carolyn L
authors: CL
authors: Westhoff
mesh_terms: D000328:Adult; D015992:Body Mass Index; D003271:Contraceptive Agents, Female / Q000008:administration & dosage / Q000097:blood*; D003274:Contraceptive Devices, Female; D017135:Desogestrel / Q000008:administration & dosage / Q000097:blood; D004997:Ethinyl Estradiol / Q000008:administration & dosage / Q000097:blood; D005260:Female; D006801:Humans; D009765:Obesity / Q000097:blood / Q000503:physiopathology*; D006080:Ovarian Follicle / Q000187:drug effects; D011446:Prospective Studies; D014621:Vagina / Q000187:drug effects / Q000502:physiology*; D055815:Young Adult
chemical_list: D003271:Contraceptive Agents, Female; C044815:etonogestrel; D004997:Ethinyl Estradiol; D017135:Desogestrel