title: Enlarged ovarian follicles in users of a levonorgestrel-releasing intrauterine system and contraceptive implant.
abstract: OBJECTIVE
  To evaluate the prevalence of enlarged ovarian follicles among users of a 20 micrograms/d levonorgestrel-releasing intrauterine system (Mirena, Leiras Oy, Turku, Finland), of subdermal contraceptive implants releasing Nestorone (Population Council, New York, New York) and of the TCu 380A intrauterine device.
  
  
  METHODS
  A cohort study was conducted at the Universidade Estadual de Campinas, Brazil. Three hundred women were enrolled, with 100 participants in each group. Bimanual pelvic examination and vaginal ultrasound were performed during routine gynecologic examinations in women without complaints. In women with enlarged ovarian follicles (> or = 25 mm), estradiol and progesterone levels were assessed weekly until disappearance or reduction of the ovarian image.
  
  
  RESULTS
  Enlarged ovarian follicles were detected in 19%, 10% and 5% of users of the levonorgestrel system, implants and intrauterine device, respectively. Most of the enlarged ovarian images disappeared after 2 weeks of follow-up. Progesterone levels showed that the intrauterine system and TCu 380A IUD (FEI, North Tonawanda, New York) users had presumably ovulated before the first ultrasound examination in contrast to the implant users.
  
  
  CONCLUSIONS
  Physicians and users should be aware that findings of enlarged ovarian follicles during the use of progestin-only contraceptives are transient and that no medical interventions are necessary.
authors.affiliation: Human Reproduction Unit, Department of Obstetrics and Gynecology, School of Medicine, Universidade Estadual de Campinas, Campinas, SP, Brazil. bahamond@caism.unicamp.br
authors.forename: Luis
authors.initials: L
authors.lastname: Bahamondes
authors.forename: Margarete
authors.initials: M
authors.lastname: Hidalgo
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Petta
authors.forename: Juan
authors.initials: J
authors.lastname: Diaz
authors.forename: Ximena
authors.initials: X
authors.lastname: Espejo-Arce
authors.forename: Cecilia
authors.initials: C
authors.lastname: Monteiro-Dantas
mesh_terms: D000328:Adult; D003271:Contraceptive Agents, Female / Q000008:administration & dosage / Q000009:adverse effects*; D004343:Drug Implants / Q000009:adverse effects*; D005260:Female; D006801:Humans; D007436:Intrauterine Devices, Medicated / Q000009:adverse effects*; D016912:Levonorgestrel / Q000008:administration & dosage / Q000009:adverse effects*; D009653:Norprogesterones / Q000008:administration & dosage / Q000009:adverse effects*; D010049:Ovarian Diseases / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000209:etiology*; D006080:Ovarian Follicle / Q000000981:diagnostic imaging; D015995:Prevalence; D012075:Remission, Spontaneous; D012720:Severity of Illness Index; D014463:Ultrasonography
chemical_list: D003271:Contraceptive Agents, Female; D004343:Drug Implants; D009653:Norprogesterones; D016912:Levonorgestrel; C029167:ST 1435