title: Predicting intrapartum fetal compromise using the fetal cerebro-umbilical ratio.
abstract: BACKGROUND
  The aim of this study was to explore the association between the cerebro-umbilical ratio measured at 35-37 weeks and intrapartum fetal compromise.
  
  
  METHODS
  This retrospective cross sectional study was conducted at the Mater Mothers' Hospital in Brisbane, Australia. Maternal demographics and fetal Doppler indices at 35-37 weeks gestation for 1381 women were correlated with intrapartum and neonatal outcomes.
  
  
  RESULTS
  Babies born by caesarean section or instrumental delivery for fetal compromise had the lowest median cerebro-umbilical ratio 1.60 (IQR 1.22-2.08) compared to all other delivery groups (vaginal delivery, emergency delivery for failure to progress, emergency caesarean section for other reasons or elective caesarean section). The percentage of infants with a cerebro-umbilical ratio <10th centile that required emergency delivery (caesarean section or instrumental delivery) for fetal compromise was 22%, whereas only 7.3% of infants with a cerebro-umbilical ratio between the 10th-90th centile and 9.6% of infants with a cerebro-umbilical ratio > 90th centile required delivery for the same indication (p < 0.001). A lower cerebro-umbilical ratio was associated with an increased risk of emergency delivery for fetal compromise, OR 2.03 (95% CI 1.41-2.92), p < 0.0001.
  
  
  CONCLUSIONS
  This study suggests that a low fetal cerebro-umbilical ratio measured at 35-37 weeks is associated with a greater risk of intrapartum compromise. This is a relatively simple technique which could be used to risk stratify women in diverse healthcare settings.
authors.affiliation: Mater Research Institute/University of Queensland, Aubigny Place, Raymond Terrace, South Brisbane, QLD 4101, Australia; Mater Mothers' Hospital, Raymond Terrace, South Brisbane, QLD 4101, Australia.
authors.forename: S
authors.initials: S
authors.lastname: Sabdia
authors.affiliation: Mater Research Institute/University of Queensland, Aubigny Place, Raymond Terrace, South Brisbane, QLD 4101, Australia.
authors.forename: R M
authors.initials: RM
authors.lastname: Greer
authors.affiliation: Mater Research Institute/University of Queensland, Aubigny Place, Raymond Terrace, South Brisbane, QLD 4101, Australia.
authors.forename: T
authors.initials: T
authors.lastname: Prior
authors.affiliation: Mater Research Institute/University of Queensland, Aubigny Place, Raymond Terrace, South Brisbane, QLD 4101, Australia; Mater Mothers' Hospital, Raymond Terrace, South Brisbane, QLD 4101, Australia; Imperial College London, UK. Electronic address: sailesh.kumar@mater.uq.edu.au.
authors.forename: S
authors.initials: S
authors.lastname: Kumar
mesh_terms: D000328:Adult; D000886:Anthropometry; D003430:Cross-Sectional Studies; D036861:Delivery, Obstetric / Q000706:statistics & numerical data; D005260:Female; D005316:Fetal Distress; D006801:Humans; D007231:Infant, Newborn; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging; D011247:Pregnancy; D011673:Pulsatile Flow; D012189:Retrospective Studies; D016216:Ultrasonography, Prenatal; D014469:Umbilical Arteries / Q000000981:diagnostic imaging
keywords: C/U ratio; Cerebro-placental ratio; Cerebro-umbilical ratio; Fetal compromise; Growth restriction; Normal growth; Pregnancy