title: The role of endometrial and subendometrial blood flows measured by three-dimensional power Doppler ultrasound in the prediction of pregnancy during IVF treatment.
abstract: BACKGROUND
  A good blood supply towards the endometrium is usually considered to be an essential requirement for implantation. We aimed to evaluate the role of endometrial and subendometrial blood flows in the prediction of pregnancy during IVF treatment.
  
  
  METHODS
  Patients undergoing the first IVF cycle were recruited. A three-dimensional (3D) ultrasound examination with power Doppler was performed on the day of oocyte retrieval to determine endometrial thickness, endometrial pattern, pulsatility index (PI) and resistance index (RI) of uterine vessels, endometrial volume, vascularization index (VI), flow index (FI) and vascularization flow index (VFI) of endometrial and subendometrial regions.
  
  
  RESULTS
  Uterine RI, endometrial VI and VFI were significantly lower in the pregnant group than the non-pregnant group. There was a non-significant trend of higher implantation and pregnancy rates in patients with absent endometrial or subendometrial blood flow. The number of embryos replaced and endometrial VI were the only two predictive factors for pregnancy. Receiver operator characteristic curve analysis revealed that the area under the curve was approximately 0.5 for all ultrasound parameters for endometrial receptivity.
  
  
  CONCLUSIONS
  Endometrial and subendometrial blood flows measured by 3D power Doppler ultrasound were not good predictors of pregnancy if they were measured at one time-point during IVF treatment.
authors.affiliation: Department of Obstetrics and Gynaecology, The University of Hong Kong, Hong Kong Special Administrative Region, People's Republic of China. nghye@hkucc.hku.hk
authors.forename: Ernest Hung Yu
authors.initials: EH
authors.lastname: Ng
authors.forename: Carina Chi Wai
authors.initials: CC
authors.lastname: Chan
authors.forename: Oi Shan
authors.initials: OS
authors.lastname: Tang
authors.forename: William Shu Biu
authors.initials: WS
authors.lastname: Yeung
authors.forename: Pak Chung
authors.initials: PC
authors.lastname: Ho
mesh_terms: D000328:Adult; D001158:Arteries / Q000000981:diagnostic imaging*; D010064:Embryo Implantation; D004624:Embryo Transfer; D004717:Endometrium / Q000098:blood supply*; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D011247:Pregnancy; D012039:Regional Blood Flow; D016896:Treatment Outcome; D018608:Ultrasonography, Doppler