title: Umbilical and fetal middle cerebral artery Doppler at 35-37 weeks' gestation in the prediction of adverse perinatal outcome.
abstract: OBJECTIVE
  To investigate the potential value of cerebroplacental ratio (CPR) at 36 weeks' gestation in the prediction of adverse perinatal outcome.
  
  
  METHODS
  This was a screening study in 6178 singleton pregnancies at 35-37 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 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 linear association between CPR and both birth-weight Z-score and arterial or venous umbilical cord blood pH, but the steepness of the regression lines was inversely related to the interval from assessment to delivery. The performance of low CPR < 5(th) percentile in screening for each adverse outcome was poor, with DRs of 6-15% and a FPR of about 6%. In the small subgroup of the population delivering within 2 weeks of assessment, the DRs improved to 14-50%, but with a simultaneous increase in FPR, to about 10%.
  
  
  CONCLUSIONS
  The performance of CPR in routine screening for adverse perinatal outcome at 36 weeks' gestation is poor.
authors.affiliation: Department of Fetal Medicine, Medway Maritime Hospital, Gillingham, Kent, UK.|Harris Birthright Research Centre for Fetal Medicine, King's College Hospital, London, UK.
authors.forename: R
authors.initials: R
authors.lastname: Akolekar
authors.affiliation: Harris Birthright Research Centre for Fetal Medicine, King's College Hospital, London, UK.
authors.forename: A
authors.initials: A
authors.lastname: Syngelaki
authors.affiliation: Harris Birthright Research Centre for Fetal Medicine, King's College Hospital, London, UK.
authors.forename: D M
authors.initials: DM
authors.lastname: Gallo
authors.affiliation: Harris Birthright Research Centre for Fetal Medicine, King's College Hospital, London, UK.
authors.forename: L C
authors.initials: LC
authors.lastname: Poon
authors.affiliation: Harris Birthright Research Centre for Fetal Medicine, King's College Hospital, London, UK.
authors.forename: K H
authors.initials: KH
authors.lastname: Nicolaides
mesh_terms: D000328:Adult; D001724:Birth Weight; D005260:Female; D005312:Fetal Blood / Q000737:chemistry; D005865:Gestational Age; D006801:Humans; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging*; D011247:Pregnancy; D011256:Pregnancy Outcome; D012044:Regression Analysis; 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