Can the cerebroplacental ratio (CPR) predict intrapartum fetal compromise? A prospective observational study

Kristien Roelens,Isabelle Dehaene,Geert Page,Ann-Sophie Page,Ellen Roets

doi:10.15761/cogrm.1000198

Abstract

Objective: To investigate the potential clinical use of serial fetal CPR measurements during the last month of pregnancy for the prediction of adverse perinatal outcome in unselected low-risk pregnancies. Methods: A multicenter prospective observational cohort study in 315 consecutively recruited low-risk pregnancies. All eligible pregnancies underwent serial sonographic evaluation of fetal weight and Doppler indices at two week intervals, from 36 weeks gestation until delivery. Data were converted into centiles correcting for gestational age. These data were not available for the obstetrical team and hence, could not influence management decisions. Primary outcomes were operative delivery for presumed fetal compromise and a composite neonatal outcome (arterial cord Ph 90th centile). Results: Three hundred fifteen women were recruited in this study. We ecxluded 32 pregnancies because of small for gestational age babies (SGA), leaving 293 women and 583 CPR values for data-analysis. There were 85 (27%) adverse neonatal outcomes and 29 patients (9%) underwent operative delivery for presumed fetal compromise. Both primary and secondary outcomes were not significant different between the different CPR groups. Furthermore, we examined if individual serial CPR measurements could predict adverse outcome and found no linear correlation between repeated measurements of CPR and adverse outcomes. Conclusion: Our study shows that routine serial screening by CPR measurements provides poor prediction for adverse perinatal outcome in uncomplicated pregnancies.

Highlights

Fetal hypoxia in the intrapartum period may result in adverse perinatal outcomes including neurologic injury, seizures and death
Several small studies showed that cerebroplacental ratio (CPR) is a better predictor for adverse perinatal outcomes than individual Doppler parameters [11,12], since the ratio may be abnormal while the Pulsatility Index (PI) of both arteries are still within the normal ranges [13]
As there was no correlation between solitary cut off points of CPR values at different gestational ages and the primary outcomes (Figure 1), we examined if individual serial CPR measurements could predict adverse outcomes

Summary

Introduction

Fetal hypoxia in the intrapartum period may result in adverse perinatal outcomes including neurologic injury, seizures (neonatal encephalopathy) and death. Several studies have shown a significant association between presence of this brain-sparing effect and adverse perinatal outcomes, in high-risk pregnancies [6,7,8,9,10]. Several small studies showed that CPR is a better predictor for adverse perinatal outcomes than individual Doppler parameters [11,12], since the ratio may be abnormal while the PIs of both arteries are still within the normal ranges [13]. The usefulness of CPR measurements in clinical follow up of low risk pregnancies remains debatable. This could be explained by the lack of evidence in the current literature, since previous studies focused on small for gestational age (SGA) fetuses. Cross-sectional and longitudinal studies led to the development of gestational age-based nomograms [24,26]

Methods

Results

Conclusion