title: Doppler velocimetry of the uterine arteries: an early screening test for miscarriage.
abstract: BACKGROUND
  According to the WHO, miscarriage is defined as "the loss of a pregnancy before the age of 20 weeks of gestation or fetal weight below 500 g". Only 50-60% of all conceptions fail to survive 20 weeks of gestation. It is estimated that about 75% of all unsuccessful conceptions are due to failed implantation and are not reported as spontaneous abortions.
  
  
  METHODS
  We performed a prospective observational study at the Department of Obstetrics and Gynecology of the Medical University Plovdiv between October 2014 and September 2015. We studied two groups of pregnant women: women with threatened abortion and those with normal pregnancy. All women underwent a transvaginal ultrasound evaluation of the uterine arterial blood flow. We measured peak systolic and end-diastolic velocity and calculated the average IR (resistance index) and S / D (systolic to diastolic ratio).
  
  
  RESULTS
  There was no association between pregnancy outcome and the mean difference between uterine arterial IR and S / (P > 0.05).
  
  
  CONCLUSIONS
  In our study, Doppler ultrasound could not differentiate between women at risk for miscarriage and normal women. Further studies are necessary to answer this question.
authors.forename: Ilian
authors.initials: I
authors.lastname: Trayanov
authors.forename: Elena
authors.initials: E
authors.lastname: Dimitrakova
mesh_terms: D000022:Abortion, Spontaneous / Q000175:diagnosis* / Q000503:physiopathology; D000328:Adult; D001783:Blood Flow Velocity / Q000502:physiology; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D017078:Laser-Doppler Flowmetry; D011247:Pregnancy; D011446:Prospective Studies; D012039:Regional Blood Flow / Q000502:physiology; D055988:Uterine Artery / Q000503:physiopathology*; D055815:Young Adult