title: Thyroid volume and Doppler evaluation of inferior thyroid artery in ultrasound: Comparison between current and previous users of oral contraceptives.
abstract: BACKGROUND
  This study aimed to compare thyroid volume and Doppler sonographic evaluation of the inferior thyroid artery using ultrasound in current and previous users of oral contraceptives (OCs).
  
  
  METHODS
  We evaluated 119 women who either currently use (n = 66) or have previously used OCs (n = 53) using color Doppler ultrasound for thyroid volume and resistance index, peak-systolic, and end-diastolic velocities of the inferior thyroid artery. Previous OC users were divided into two groups: previous OC use for <1 year and previous OC use for ≥1 year.
  
  
  RESULTS
  A comparison of the thyroid volume revealed an increased volume in women with previous OC use for ≥1 year and in current users compared with those with previous OC use for <1 year (previous OC use for ≥1 year: 7.49 mL versus previous OC use for <1 year: 6.13 mL; p < 0.01). The relationship between OC use and an enlarged thyroid remained after adjusting for thyroid-stimulating hormone levels (p = 0.03). There were no differences in the inferior thyroid artery blood flow measurements.
  
  
  CONCLUSIONS
  In healthy women, current use and previous OC use for ≥1 year were associated with increased thyroid volume that was unrelated to increased blood flow in the gland.
authors.affiliation: Medical Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Tiago Severo
authors.initials: TS
authors.lastname: Garcia
authors.forename: Tatiana Helena
authors.initials: TH
authors.lastname: Rech
mesh_terms: D000328:Adult; D001158:Arteries / Q000000981:diagnostic imaging; D003276:Contraceptives, Oral; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D009929:Organ Size; D013961:Thyroid Gland / Q000033:anatomy & histology / Q000098:blood supply* / Q000000981:diagnostic imaging*; D018615:Ultrasonography, Doppler, Color; D055815:Young Adult
chemical_list: D003276:Contraceptives, Oral
keywords: Doppler ultrasonography; oral contraceptives; thyroid volume; ultrasonography