title: Umbilical and fetal middle cerebral artery Doppler at 30-34 weeks' gestation in the prediction of adverse perinatal outcome.
abstract: OBJECTIVE
  To investigate the potential value of cerebroplacental ratio (CPR) at 30-34 weeks' gestation in the prediction of adverse perinatal outcome.
  
  
  METHODS
  This was a screening study in 30 780 singleton pregnancies at 30-34 weeks' gestation. Umbilical artery (UA) and fetal middle cerebral artery (MCA) pulsatility index (PI) were measured and the values were converted to multiples of the median (MoM) after adjustment from variables in maternal characteristics and medical history that affect the measurements. CPR was calculated by dividing MCA-PI MoM by UA-PI MoM. Multivariable logistic regression analysis was used to determine if measuring CPR improved the prediction of adverse perinatal outcome provided by screening with maternal characteristics, medical history and obstetric factors. The detection rate (DR) and false-positive rate (FPR) of screening by CPR were estimated for stillbirth, Cesarean section for fetal distress, umbilical arterial cord blood pH ≤ 7.0, umbilical venous cord blood pH ≤ 7.1, 5-min Apgar score < 7 and admission to the neonatal unit (NNU) and neonatal intensive care unit (NICU).
  
  
  RESULTS
  There was a significant association between CPR and birth-weight Z-score. In addition to maternal characteristics, medical history and obstetric factors, measuring CPR provided a significant contribution to the prediction of arterial cord blood pH ≤ 7.0, venous cord blood pH ≤ 7.1 and admission to NNU. The performance of CPR in screening for each adverse outcome was poor, with DR of 5-11% and a FPR of about 5%. In the small subgroup of the population delivering within 2 weeks following assessment, the DR improved to 20-50%, but with a simultaneous increase in FPR to 10-23%.
  
  
  CONCLUSIONS
  The performance of CPR in routine screening for adverse perinatal outcome at 30-34 weeks' gestation is poor.
authors: Harris Birthright Research Centre for Fetal Medicine, King's College Hospital, London, UK.
authors: S
authors: S
authors: Bakalis
authors: R
authors: R
authors: Akolekar
authors: D M
authors: DM
authors: Gallo
authors: L C
authors: LC
authors: Poon
authors: K H
authors: KH
authors: Nicolaides
mesh_terms: D000328:Adult; D005260:Female; D005312:Fetal Blood / Q000737:chemistry; D005316:Fetal Distress / Q000000981:diagnostic imaging; D005333:Fetus / Q000098:blood supply; D005865:Gestational Age; D006801:Humans; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging*; D011237:Predictive Value of Tests; D011247:Pregnancy; D011256:Pregnancy Outcome; D011446:Prospective Studies; D011673:Pulsatile Flow / Q000502:physiology; D018615:Ultrasonography, Doppler, Color; D016216:Ultrasonography, Prenatal / Q000379:methods; D014469:Umbilical Arteries / Q000000981:diagnostic imaging*
keywords: middle cerebral artery Doppler; pyramid of antenatal care; small-for-gestational age; third-trimester screening; umbilical artery Doppler