title: Absent umbilical artery end-diastolic velocity in growth-restricted fetuses: a risk factor for neonatal thrombocytopenia.
abstract: OBJECTIVE
  To examine the relationship between umbilical artery (UA) end-diastolic flow and neonatal thrombocytopenia.
  
  
  METHODS
  We prospectively examined 115 anatomically normal single fetuses with UA pulsatility indices more than two standard deviations above the gestational age mean and subsequent birth weights below the tenth percentile. Peripheral neonatal platelet counts in fetuses with positive UA end-diastolic velocity were compared with those of fetuses with absent or reversed UA end-diastolic velocity.
  
  
  RESULTS
  Sixty-seven fetuses (58.3%) had positive UA end-diastolic velocity and 48 (41.7%) had absent or reversed UA end-diastolic velocity. Three neonates in the positive-flow group and 22 neonates in the absent- or reversed-flow group had platelet counts of less than 100, 000/mm(3) (relative risk 10.2; 95% confidence interval; 3.2, 32.3; P <.001). Absent or reversed end-diastolic velocity had a sensitivity of 88%, specificity of 71%, positive predictive value of 46%, and negative predictive value of 96% for predicting neonatal thrombocytopenia. Neonates with absent or reversed flow also had lower median platelet counts (101,500/mm(3) versus 208,000/mm(3), P <.001), hemoglobin levels (15.1 versus 16.4 g/dL, P <.01), and hematocrits (47.6 versus 51.1%, P <.05), as well as higher nucleated red blood cell counts (191 versus 15 per 100 white blood cells, P <. 001).
  
  
  CONCLUSIONS
  Absent or reversed UA end-diastolic velocity in growth-restricted fetuses is associated with a statistically significant increase in risk of neonatal thrombocytopenia.
authors.affiliation: Department of Obstetrics, Gynecology and Reproductive Sciences, University of Maryland, Baltimore, Maryland, USA.
authors.forename: A A
authors.initials: AA
authors.lastname: Baschat
authors.forename: U
authors.initials: U
authors.lastname: Gembruch
authors.forename: I
authors.initials: I
authors.lastname: Reiss
authors.forename: L
authors.initials: L
authors.lastname: Gortner
authors.forename: C P
authors.initials: CP
authors.lastname: Weiner
authors.forename: C R
authors.initials: CR
authors.lastname: Harman
mesh_terms: D000293:Adolescent; D000328:Adult; D001783:Blood Flow Velocity; D003971:Diastole; D005260:Female; D005317:Fetal Growth Retardation / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006801:Humans; D007231:Infant, Newborn; D016014:Linear Models; D008875:Middle Aged; D010976:Platelet Count; D011237:Predictive Value of Tests; D011247:Pregnancy; D011263:Pregnancy Trimester, Third; D011446:Prospective Studies; D011673:Pulsatile Flow; D012307:Risk Factors; D013921:Thrombocytopenia / Q000175:diagnosis*; D018608:Ultrasonography, Doppler / Q000592:standards; D016216:Ultrasonography, Prenatal / Q000592:standards*; D014469:Umbilical Arteries / Q000000981:diagnostic imaging* / Q000196:embryology / Q000502:physiology