title: Influence of different hormonal regimens on endometrial microvascular density and VEGF expression in women suffering from breakthrough bleeding.
abstract: BACKGROUND
  The aim of this study was to quantify blood vessel density (BVD) and immunoreactive vascular endothelial growth factor (VEGF) levels in endometrial biopsies taken from women suffering breakthrough bleeding (BTB) under different exogenous hormonal regimes.
  
  
  METHODS
  Endometrial biopsies from women in Melbourne with BTB were divided into four groups: combined-continuous hormone therapy (HT) (estrogen and progestin taken daily), cyclical HT (daily estrogen with progestin for 14 days each cycle), progestin-only, or no HT. Subjects from Barcelona were using the Mirena intrauterine levonorgestrel-releasing system for contraceptive purposes, with menstrual diaries for classification into four groups (amenorrhea, infrequent, regular and prolonged). Control biopsies from Melbourne were included in the study. Endometrial samples were immunostained for VEGF and blood vessel localization using an antibody to CD34.
  
  
  RESULTS
  Results showed that BVD was significantly reduced in the progestin-only treated group compared with the other three treatment groups (P = 0.028). In addition, all four Mirena BTB groups had significantly reduced BVD compared with controls. Considerable heterogeneity was observed in VEGF immunostaining within and between individual samples with no major differences between HT or Mirena.
  
  
  CONCLUSIONS
  These results provide strong evidence that unopposed progestins reduce endometrial BVD and that there is no link between VEGF immunostaining and BVD or BTB.
authors.affiliation: Centre for Women's Health Research, Clinic, Monash University Department of Obstetrics & Gynaecology, Monash Medical Centre, Clayton, Victoria 3168, Australia. peter.rogers@med.monash.edu.au
authors.forename: P A W
authors.initials: PA
authors.lastname: Rogers
authors.forename: F
authors.initials: F
authors.lastname: Martinez
authors.forename: J E
authors.initials: JE
authors.lastname: Girling
authors.forename: F
authors.initials: F
authors.lastname: Lederman
authors.forename: L
authors.initials: L
authors.lastname: Cann
authors.forename: E
authors.initials: E
authors.lastname: Farrell
authors.forename: F
authors.initials: F
authors.lastname: Tresserra
authors.forename: N
authors.initials: N
authors.lastname: Patel
mesh_terms: D000328:Adult; D018952:Antigens, CD34 / Q000096:biosynthesis; D001706:Biopsy; D003270:Contraceptive Agents / Q000494:pharmacology; D004717:Endometrium / Q000187:drug effects*; D004967:Estrogens / Q000494:pharmacology*; D005260:Female; D006728:Hormones / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D008796:Metrorrhagia; D008833:Microcirculation / Q000187:drug effects*; D008875:Middle Aged; D011372:Progestins / Q000494:pharmacology*; D042461:Vascular Endothelial Growth Factor A / Q000096:biosynthesis* / Q000378:metabolism
chemical_list: D018952:Antigens, CD34; D003270:Contraceptive Agents; D004967:Estrogens; D006728:Hormones; D011372:Progestins; D042461:Vascular Endothelial Growth Factor A