title: Ductus venosus Doppler velocimetry in the prediction of acidemia at birth: which is the best parameter?
abstract: OBJECTIVE
  To evaluate the prediction of acidemia at birth using ductus venosus Doppler velocimetry and to determine the best parameter and cut-off values for this prediction in pregnancies complicated with placental insufficiency.
  
  
  METHODS
  Prospective cross-sectional study. Forty-seven patients with placental insufficiency managed in two Brazilian hospitals were submitted to ductus venosus Doppler velocimetry in the last 24 h before delivery. All pregnancies were singleton, at least 26 weeks of age and without structural or chromosomal anomalies. A ROC curve was calculated for each ductus venosus parameter (independent variable) and acidemia (dependent variable). A cut-off value was established. The McNemar test was used to compare the various parameters.
  
  
  RESULTS
  The ductus venosus S, D and A peak velocities were not good predictors of acidemia at birth. Pulsatility Index for Veins (PIV) was a good predictor of acidemia (ROC curve area 0.79, p = 0.003), as well as S/A and (S - A)/S ratios (ROC curve area 0.818, p = 0.001). The cut-off values were PIV = 0.76, S/A = 2.67 and (S - A)/S = 0.63.
  
  
  CONCLUSIONS
  In this high-risk population, angle-independent ductus venosus Doppler indexes were good predictors of birth acidemia. The S/A and (S - A)/S ratios and the ductus venosus PIV were statistically equivalent in this prediction.
authors.affiliation: São Paulo Hospital, São Paulo Federal University, Paulista Medical School, Brazil. herlaniocosta@uol.com.br
authors.forename: Francisco Herlânio Costa
authors.initials: FH
authors.lastname: Carvalho
authors.forename: Antonio Fernandes
authors.initials: AF
authors.lastname: Moron
authors.forename: Rosiane
authors.initials: R
authors.lastname: Mattar
authors.forename: Renato Martins
authors.initials: RM
authors.lastname: Santana
authors.forename: Carlos Geraldo Viana
authors.initials: CG
authors.lastname: Murta
authors.forename: Maurício Mendes
authors.initials: MM
authors.lastname: Barbosa
authors.forename: Maria Regina
authors.initials: MR
authors.lastname: Torloni
authors.forename: Flávio Augusto Prado
authors.initials: FA
authors.lastname: Vasques
mesh_terms: D000138:Acidosis / Q000175:diagnosis*; D003430:Cross-Sectional Studies; D005260:Female; D005312:Fetal Blood / Q000737:chemistry; D005315:Fetal Diseases / Q000175:diagnosis*; D006801:Humans; D017078:Laser-Doppler Flowmetry / Q000379:methods*; D010927:Placental Insufficiency / Q000000981:diagnostic imaging / Q000503:physiopathology*; D011237:Predictive Value of Tests; D011247:Pregnancy; D011446:Prospective Studies; D011673:Pulsatile Flow; D012372:ROC Curve; D014463:Ultrasonography