Correlation of Cerebroplacental Ratio (CPR) With Adverse Perinatal Outcome in Singleton Pregnancies

Systematic review evaluating the efficacy of the cerebroplacental ratio (CPR) in saving babies lives

Introduction

The aim of this systematic review is to critically assess the efficacy of the cerebroplacental ratio performed in the third trimester at predicting adverse perinatal outcomes and reducing stillbirth rates.

Method

The literature search was performed using CINAHL, EMBASE, EMCARE, MEDLINE and PubMed including systematic reviews, retrospective and prospective studies from inception until July 2020 utilising the PRISMA checklist and flowchart. Data displaying sensitivities, specificity and odds ratios (OR) to include 95% confidence interval (CI) were extracted and synthesised.

Findings

Initially, 1226 studies were identified, and nine studies met the inclusion criteria. Sample sizes ranged from 491 to 9772 pregnancies. The cerebroplacental ratio had the strongest diagnostic accuracy of all of the independent variables for detecting fetal demise (mean sensitivity and specificity; 79% and 78%). The cerebroplacental ratio, however, did not perform as favourably at predicting operative delivery (mean sensitivity and specificity; 59% and 82%) or anticipating admission to the neonatal intensive care unit (mean sensitivity and specificity; 55% and 74%).

Discussion

The results from this study showed that the cerebroplacental ratio within third trimester pregnancies has been proven to have moderate to high diagnostic value when detecting adverse perinatal outcomes, in particular fetal demise.

Conclusion

Cerebroplacental ratio has the potential as a diagnostic tool to reduce adverse perinatal outcomes, in particular fetal demise and help reduce stillbirth rates. The main study limitation involved heterogeneity within the included studies, in particular with a regard to blinding.

Fetal Growth Restriction - Diagnostic Work-up, Management and Delivery

Fetal or intrauterine growth restriction (FGR/IUGR) affects approximately 5 – 8% of all pregnancies and refers to a fetus not exploiting its genetically determined growth potential. Not only a major cause of perinatal morbidity and mortality, it also predisposes these fetuses to the development of chronic disorders in later life. Apart from the timely diagnosis and identification of the causes of FGR, the obstetric challenge primarily entails continued antenatal management with optimum timing of delivery. In order to minimise premature birth morbidity, intensive fetal monitoring aims to prolong the pregnancy and at the same time intervene, i.e. deliver, before the fetus is threatened or harmed. It is important to note that early-onset FGR (< 32 + 0 weeks of gestation [wks]) should be assessed differently than late-onset FGR (≥ 32 + 0 wks). In early-onset FGR progressive deterioration is reflected in abnormal venous Doppler parameters, while in late-onset FGR this manifests primarily in abnormal cerebral Doppler ultrasound. According to our current understanding, the “optimum” approach for monitoring and timing of delivery in early-onset FGR combines computerized CTG with the ductus venosus Doppler, while in late-onset FGR assessment of the cerebral Doppler parameters becomes more important.