title: Change in endometrial thickness in postmenopausal women undergoing hormone replacement therapy.
abstract: OBJECTIVE
  To evaluate the effect over time of hormone replacement on endometrial thickness in asymptomatic postmenopausal women.
  
  
  METHODS
  Endometrial thickness was measured on 644 sonograms of 120 postmenopausal volunteers receiving no hormones or one of three hormone regimens. Each subject underwent ultrasound (US) two to nine times. In addition, eight women using sequential hormones underwent US seven to 20 times over 2 months. The greatest endometrial thickness and change in endometrial thickness over time were evaluated.
  
  
  RESULTS
  Endometrial thickness was statistically significantly greater in women using sequential hormones (8 mm) compared with that in control subjects (5 mm). Change in endometrial thickness (> 3-mm difference) was seen in 23 of 40 women using sequential hormones compared with six of 61 controls. Women using sequential hormones demonstrated maximum endometrial thickness on days 13-23 of the cycle.
  
  
  CONCLUSIONS
  Women using sequential hormones show greater endometrial thickness than that in controls and show the most variation in measurements. They should undergo US either early or late in the hormone cycle to evaluate the endometrium at its thinnest.
mesh_terms: D000005:Abdomen; D000368:Aged; D001706:Biopsy; D004334:Drug Administration Schedule; D004717:Endometrium / Q000000981:diagnostic imaging* / Q000187:drug effects* / Q000473:pathology; D015914:Estrogen Replacement Therapy; D004967:Estrogens / Q000008:administration & dosage / Q000627:therapeutic use*; D004966:Estrogens, Conjugated (USP) / Q000008:administration & dosage / Q000627:therapeutic use; D005122:Exudates and Transudates / Q000000981:diagnostic imaging; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D017258:Medroxyprogesterone Acetate / Q000008:administration & dosage / Q000627:therapeutic use; D008597:Menstrual Cycle; D008875:Middle Aged; D017698:Postmenopause; D012189:Retrospective Studies; D014463:Ultrasonography; D014621:Vagina
chemical_list: D004967:Estrogens; D004966:Estrogens, Conjugated (USP); D017258:Medroxyprogesterone Acetate