title: Changes in blood-flow impedance of the human corpus luteum throughout the luteal phase and during early pregnancy.
abstract: OBJECTIVE
  To examine changes in blood flow in the corpus luteum throughout the luteal phase and during early pregnancy.
  
  
  METHODS
  Longitudinal and cross-sectional prospective studies.
  
  
  METHODS
  University hospital and city general hospital.
  
  
  METHODS
  Sixty-one women with normal menstrual cycles and normal luteal function, 13 women with hCG-induced ovulatory cycle, 10 women with luteal phase defect, six women with luteinized unruptured follicle (LUF), and 17 pregnant women (4-10 weeks of gestation).
  
  
  METHODS
  Blood-flow impedance in the corpus luteum was assessed by transvaginal color-pulsed Doppler ultrasound.
  
  
  METHODS
  Resistance index (RI) in the corpus luteum.
  
  
  RESULTS
  In the normal menstrual cycle, the RI of the preovulatory follicle was high and significantly decreased after ovulation. Luteal-RI further decreased during the early to midluteal phase but significantly increased during the late luteal phase. Those changes in luteal-RI were similar to those of the hCG-induced ovulatory cycle. Luteal-RI during the midluteal phase was significantly higher in the patients with luteal phase defect than in women with normal luteal function. Luteal-RI of the LUF patients remained high throughout the luteal phase. In pregnant women, luteal-RI remained at the midluteal phase level until 7 weeks of gestation and significantly increased thereafter.
  
  
  CONCLUSIONS
  The change in luteal-RI was associated with corpus luteum development and corpus luteum regression. Luteal-RI was closely associated with luteal function.
authors.affiliation: Department of Obstetrics and Gynecology, Yamaguchi University Graduate School of Medicine, Ube, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tamura
authors.forename: Akihisa
authors.initials: A
authors.lastname: Takasaki
authors.forename: Ken
authors.initials: K
authors.lastname: Taniguchi
authors.forename: Aki
authors.initials: A
authors.lastname: Matsuoka
authors.forename: Katsunori
authors.initials: K
authors.lastname: Shimamura
authors.forename: Norihiro
authors.initials: N
authors.lastname: Sugino
mesh_terms: D000328:Adult; D003338:Corpus Luteum / Q000098:blood supply* / Q000000981:diagnostic imaging; D003430:Cross-Sectional Studies; D005260:Female; D005865:Gestational Age; D006801:Humans; D007564:Japan; D008137:Longitudinal Studies; D008183:Luteal Phase; D010049:Ovarian Diseases / Q000503:physiopathology; D006080:Ovarian Follicle / Q000098:blood supply* / Q000000981:diagnostic imaging; D010062:Ovulation Induction; D011247:Pregnancy; D011374:Progesterone / Q000097:blood; D011446:Prospective Studies; D012039:Regional Blood Flow; D018615:Ultrasonography, Doppler, Color; D018617:Ultrasonography, Doppler, Pulsed; D014655:Vascular Resistance
chemical_list: D011374:Progesterone