title: Uterine artery pulsatility index at 30-34 weeks' gestation in the prediction of adverse perinatal outcome.
abstract: OBJECTIVE
  To investigate the potential value of uterine artery (UtA) Doppler 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. UtA pulsatility index (UtA-PI) was measured and the values were converted to multiples of the median (MoM) after adjustment for variables relating to maternal characteristics and medical history that affect the measurements. Multivariable logistic regression analysis was used to determine if measuring UtA-PI 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 UtA-PI were estimated for stillbirth, Cesarean section for fetal distress, umbilical arterial cord blood pH ≤ 7.0 or umbilical venous cord blood pH ≤ 7.1 and 5-min Apgar score < 7.
  
  
  RESULTS
  The incidence of adverse perinatal outcome was higher in small-for-gestational-age (SGA) fetuses than in non-SGA fetuses, but the majority of cases with each adverse outcome were in the non-SGA group, including about 70% of stillbirths and more than 80% with Cesarean section for fetal distress, low cord blood pH and low Apgar score. The performance of UtA-PI > 95(th) percentile in screening for each adverse outcome was poor with DR of 6-16% and a FPR of 5-6%. The DR of adverse outcome when screening by high UtA-PI was greater in pregnancies complicated by SGA than in non-SGA pregnancies; 24% vs 13% for stillbirth, 15% vs 5% for Cesarean section for fetal distress, 30% vs 9% for low cord blood pH and 20% vs 3% for low 5-min Apgar score, respectively.
  
  
  CONCLUSIONS
  High UtA-PI at 30-34 weeks' gestation may be useful in the prediction of adverse perinatal outcome in pregnancies with a SGA fetus, however, in the absence of SGA, UtA-PI is a poor predictor of adverse outcome. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.
authors.affiliation: Harris Birthright Research Centre for Fetal Medicine, King's College Hospital, London, UK.
authors.forename: N
authors.initials: N
authors.lastname: Valiño
authors.affiliation: Harris Birthright Research Centre for Fetal Medicine, King's College Hospital, London, UK.
authors.forename: G
authors.initials: G
authors.lastname: Giunta
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.|Department of Fetal Medicine, Medway Maritime Hospital, Gillingham, Kent, 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: K H
authors.initials: KH
authors.lastname: Nicolaides
mesh_terms: D000328:Adult; D005260:Female; D005316:Fetal Distress / Q000000981:diagnostic imaging*; D006801:Humans; D011237:Predictive Value of Tests; D011247:Pregnancy; D011263:Pregnancy Trimester, Third / Q000502:physiology; D011446:Prospective Studies; D011673:Pulsatile Flow / Q000502:physiology; D050497:Stillbirth; D018615:Ultrasonography, Doppler, Color / Q000379:methods; D016216:Ultrasonography, Prenatal / Q000379:methods*; D055988:Uterine Artery / Q000000981:diagnostic imaging*
keywords: pyramid of antenatal care; small-for-gestational age; third-trimester screening; uterine artery Doppler