title: Ovarian function with the contraceptive vaginal ring or an oral contraceptive: a randomized study.
abstract: BACKGROUND
  The effects on ovarian function of the combined contraceptive vaginal ring NuvaRing and a combined oral contraceptive (COC) were compared.
  
  
  METHODS
  This randomized, open-label study was performed in 40 healthy female volunteers, who were randomized by a computer-generated list after stratification for the ovulation day in a pretreatment cycle. They received two cycles of NuvaRing (21 subjects) or a COC (30 microg ethinylestradiol and 150 microg levonorgestrel, 19 subjects). NuvaRing was started on cycle day 5, COC on cycle day 1. Follicular diameter, endometrial thickness and FSH, LH, 17beta-estradiol (E2) and progesterone concentrations were determined.
  
  
  RESULTS
  The median maximum follicular diameter (maxFD) was < or =11 mm during treatment. In the first treatment cycle the maxFD was lower in the COC than in the NuvaRing group, due to the different starting procedures. MaxFD were not different in the second treatment cycle. In both groups, E2 and progesterone levels remained low during treatment. Ovulations did not occur.
  
  
  CONCLUSIONS
  In both groups, ovarian activity was adequately suppressed. Due to the different starting procedures, lower ovarian activity was observed in the COC group in the first treatment cycle. In the second cycle, ovarian suppression was comparable with NuvaRing and COC treatment.
authors.affiliation: Dinox Medical Investigations, Groenewoudseweg 317, 6524 TX Nijmegen, The Netherlands.
authors.forename: Ingrid J M
authors.initials: IJ
authors.lastname: Duijkers
authors.forename: Christine
authors.initials: C
authors.lastname: Klipping
authors.forename: Carole H J
authors.initials: CH
authors.lastname: Verhoeven
authors.forename: Thom O M
authors.initials: TO
authors.lastname: Dieben
mesh_terms: D000293:Adolescent; D000328:Adult; D003271:Contraceptive Agents, Female / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000494:pharmacology*; D003274:Contraceptive Devices, Female; D003276:Contraceptives, Oral / Q000493:pharmacokinetics / Q000494:pharmacology*; D003277:Contraceptives, Oral, Combined / Q000008:administration & dosage / Q000494:pharmacology; D004717:Endometrium / Q000033:anatomy & histology / Q000187:drug effects; D004958:Estradiol / Q000097:blood; D004997:Ethinyl Estradiol / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000494:pharmacology*; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood; D006801:Humans; D016912:Levonorgestrel / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000494:pharmacology*; D007986:Luteinizing Hormone / Q000097:blood; D008597:Menstrual Cycle; D006080:Ovarian Follicle / Q000187:drug effects; D010053:Ovary / Q000187:drug effects / Q000502:physiology*; D011374:Progesterone / Q000097:blood; D014621:Vagina
chemical_list: D003271:Contraceptive Agents, Female; D003276:Contraceptives, Oral; D003277:Contraceptives, Oral, Combined; D004997:Ethinyl Estradiol; D011374:Progesterone; D004958:Estradiol; D016912:Levonorgestrel; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone