title: Doppler for growth restriction: the association between the cerebroplacental ratio and a reduced interval to delivery.
abstract: OBJECTIVE
  Evaluation of the cerebroplacental ratio (CPR) as an adjunct to umbilical artery Doppler (UA) to assess risk of delivery before 32 weeks and/or delivery within 2 weeks from diagnosis of fetal growth restriction (FGR).
  
  
  METHODS
  In a cohort of fetuses with suspected FGR, UA Doppler was performed, and when abnormal the CPR was calculated (middle cerebral pulsatility index/umbilical artery pulsatility index). Doppler characteristics were used to determine three study groups: (1) normal UA, (2) abnormal UA with normal CPR and (3) abnormal UA with abnormal CPR. The primary outcomes were delivery before 32 weeks and delivery within 2 weeks. Adjusted odds ratio (aOR) with 95% confidence intervals (CIs) were calculated controlling for maternal age, chronic hypertension and tobacco use. We performed a linear regression analysis comparing the value of the CPR with the gestational age at delivery. Kaplan-Meier survival curve analysis with log-rank tests for probability was performed.
  
  
  RESULTS
  We included 154 patients: 91, 31 and 32 in Group 1, 2 and 3, respectively. Subjects in Group 3 had higher rates of the two primary outcomes: there was a fivefold increased risk (aOR=5.2 (95% CI=2.85-9.48)) for delivery before 32 weeks and over a fourfold increased risk for delivery within 2 weeks (aOR=4.76 (95% CI=2.32-9.76)) compared with those with a normal CPR (Group 1). In contrast, subjects in Group 2 (abnormal UA Doppler but normal CPR) had a similar rate of delivery before 32 weeks (aOR=1.16 (95% CI=0.55-2.48)) and within 2 weeks (aOR=1.07 (95% CI=0.43-2.69)). The median gestational age at delivery was 36, 36 and 29 weeks in Groups 1, 2 and 3, respectively (P<0.001). Linear regression analysis revealed a strong correlation between the value of the CPR and gestational age at delivery: R(2)=0.56, correlation coefficient=0.75. Kaplan-Meier analysis revealed a significantly decreased latency to delivery in Group 3, as opposed to Groups 1 and 2 (Cox-Mantel hazard ratio (HR) of Group 2 versus Group 1 HR=1.20 (95% CI=0.78-1.83) and Group 3 versus Group 1 HR=5.00 (95% CI=2.4-10.21)).
  
  
  CONCLUSIONS
  The CPR differentiates those fetuses with suspected growth restriction most at risk for delivery before 32 weeks and delivery within 2 weeks from those likely to have a more prolonged latency until delivery is required. In patients with suspected FGR and an abnormal UA, the CPR can be used to guide management decisions, such as maternal hospitalization and/or transport, aggressive fetal monitoring and antenatal corticosteroid administration.
authors.affiliation: Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, University of Cincinnati College of Medicine, Cincinnati, OH, USA.
authors.forename: C R
authors.initials: CR
authors.lastname: Warshak
authors.affiliation: Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, University of Cincinnati College of Medicine, Cincinnati, OH, USA.
authors.forename: H
authors.initials: H
authors.lastname: Masters
authors.affiliation: Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, University of Cincinnati College of Medicine, Cincinnati, OH, USA.
authors.forename: J
authors.initials: J
authors.lastname: Regan
authors.affiliation: 1] Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, University of Cincinnati College of Medicine, Cincinnati, OH, USA [2] Center for Prevention of Preterm Birth, Perinatal Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
authors.forename: E
authors.initials: E
authors.lastname: DeFranco
mesh_terms: D000328:Adult; D005260:Female; D005317:Fetal Growth Retardation / Q000503:physiopathology*; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D053208:Kaplan-Meier Estimate; D016015:Logistic Models; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging*; D015999:Multivariate Analysis; D011247:Pregnancy; D011256:Pregnancy Outcome; D047928:Premature Birth / Q000503:physiopathology*; D012189:Retrospective Studies; D018608:Ultrasonography, Doppler; D016216:Ultrasonography, Prenatal; D014469:Umbilical Arteries / Q000000981:diagnostic imaging*; D055815:Young Adult