title: A randomized double-blind comparison of perifollicular vascularity and endometrial receptivity in ovulatory women taking clomiphene citrate at two different times.
abstract: BACKGROUND
  It is still controversial whether the day of clomiphene citrate initiation has any impact on the pregnancy rate. This study aimed to compare the perifollicular vascularity and endometrial receptivity of ovulatory women who started clomiphene citrate on day 2 and day 5.
  
  
  METHODS
  Thirty-five women with regular ovulatory cycles were first monitored in a natural cycle and then randomized by computer-generated random numbers put in sealed opaque envelopes to receive 50 mg clomiphene citrate on days 2-6 or on days 5-9. The hormonal profile, the number of dominant follicles, the grading of perifollicular vascularity, endometrial thickness and Doppler flow indices of uterine/subendometrial arteries were compared between both groups.
  
  
  RESULTS
  All the above parameters were similar for both groups on the day of the LH surge and 7 days after the LH surge.
  
  
  CONCLUSIONS
  There were no differences in oocyte quality graded by the perifollicular vascularity and the endometrial receptivity assessed by endometrial thickness and Doppler flow indices of uterine and subendometrial vessels when clomiphene citrate was started in regularly ovulatory women on day 2 or on day 5.
authors.affiliation: Department of Obstetrics and Gynaecology, The University of Hong Kong, Queen Mary Hospital, Pokfulam Road, Hong Kong Special Administrative Region, People's Republic of China. w8382982@netvigator.com
authors.forename: Wai
authors.initials: W
authors.lastname: Cheung
authors.forename: Ernest Hung Yu
authors.initials: EH
authors.lastname: Ng
authors.forename: Pak Chung
authors.initials: PC
authors.lastname: Ho
mesh_terms: D000328:Adult; D001808:Blood Vessels / Q000033:anatomy & histology / Q000187:drug effects; D002996:Clomiphene / Q000008:administration & dosage*; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D004717:Endometrium / Q000098:blood supply / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000502:physiology*; D005260:Female; D005300:Fertility Agents, Female / Q000008:administration & dosage*; D006801:Humans; D007986:Luteinizing Hormone / Q000378:metabolism; D009865:Oocytes / Q000502:physiology; D006080:Ovarian Follicle / Q000098:blood supply*; D010060:Ovulation; D012039:Regional Blood Flow; D014463:Ultrasonography; D014599:Uterus / Q000098:blood supply
chemical_list: D005300:Fertility Agents, Female; D002996:Clomiphene; D007986:Luteinizing Hormone