European Journal of Cardiovascular Medicine

Fetal growth restriction (FGR) continues to present a significant challenge in obstetrics due to its association with adverse perinatal outcomes and long-term health implications for newborns. It necessitates vigilant antenatal monitoring and timely interventions to mitigate risks. ¹ Among the parameters assessed for fetal well-being, the cerebroplacental ratio (CPR) has emerged as a promising marker for evaluating fetal compromise and predicting perinatal outcomes. ²

The CPR, derived from Doppler ultrasound measurements, involves dividing the middle cerebral artery pulsatility index (MCA-PI) by the umbilical artery pulsatility index (UA-PI). ² This non-invasive technique provides insights into fetal cerebral and placental circulations, reflecting the balance between fetal oxygen demand and supply. ³ A decreased CPR indicates increased placental resistance relative to fetal cerebral circulation, suggesting compromised placental function and fetal growth. ^{3, 4}

Studies have explored the utility of CPR in identifying FGR and predicting perinatal outcomes. For instance, Cruz-Martínez et al. ⁵ demonstrated that reduced CPR is associated with an increased risk of adverse perinatal outcomes, including neonatal acidemia and neonatal intensive care unit (NICU) admission. Similarly, Khalil et al. ⁶ highlighted CPR's potential as a predictor of adverse neonatal outcomes in FGR pregnancies.

However, conflicting findings regarding CPR's clinical efficacy and optimal cutoff values persist in the literature. ⁴ Further exploration of its correlation with specific neonatal outcomes, such as NICU admissions and morbidity, is needed to refine risk stratification strategies and improve perinatal care practices. ⁷

Our study aims to contribute to this body of knowledge by synthesizing evidence on CPR's role in FGR assessment and its correlation with perinatal outcomes. Our findings may inform evidence-based decision-making processes, facilitate timely interventions, and improve perinatal outcomes for infants at risk of FGR-related complications. Hence, the study seeks to assess the predictive value of the cerebroplacental ratio (MCA PI/UA PI) in detecting adverse perinatal outcomes in clinically suspected FGR pregnancies, aiming to reduce associated morbidity and mortality through early detection strategies.

This prospective observational study was conducted at the Department of Obstetrics and Gynaecology, Jaipur Golden Hospital, Rohini, New Delhi, between July 2018 and May 2019.

Participants:

80 pregnant women attending the antenatal outpatient clinic were enrolled in the study after obtaining written and informed consent. Inclusion criteria comprised singleton pregnancies with fetal gestational age above 30 weeks and clinical suspicion of FGR. High-risk pregnancies that underwent Doppler studies were also included. Exclusion criteria encompassed multiple gestations, congenital anomalies, and pregnancies below 30 weeks gestation.

Data Collection and Analysis:

Detailed histories were obtained from all antenatal women beyond 30 weeks of gestational age, followed by comprehensive general physical, systemic, and obstetric examinations. Cases clinically suspected of FGR underwent ultrasound and Doppler studies to assess UA PI and MCA PI. The cerebroplacental ratio (MCA PI/UA PI) was calculated, with a ratio considered abnormal if less than 1.

Perinatal Outcome Measures:

Perinatal outcomes were evaluated based on the mode of delivery, birth weight below the 10th centile for gestational age, Apgar score less than 7 at 5 minutes, neonatal resuscitation, neonates requiring intubation, NICU admission exceeding 24 hours, and neonatal death.

Ethical Considerations:

The institutional ethics committee approved the study protocol, and all procedures were conducted per ethical standards and guidelines for human research. Written informed consent was obtained from all participants before enrollment in the study.

Statistical analysis:

Statistical analysis was performed using SPSS version 25 version. Sensitivity, specificity, positive and negative predictive values, and diagnostic accuracy were calculated using the chi-square test. The level of significance was set at 5%.

The present study investigated the CPR predictive value of perinatal outcomes in pregnancies suspected of FGR. The distribution of CPR values among the study participants revealed that 47.5% had a CPR of less than 1, while 52.5% had a CPR of 1 or greater. This distribution underscores the prevalence of abnormal CPR values in the study population, indicating a significant proportion of pregnancies with potential fetal compromise.

Our findings demonstrated a significant association between abnormal CPR values and adverse perinatal outcomes across various parameters. For instance, a lower CPR was strongly correlated with an increased likelihood of cesarean delivery (p < 0.001), birth weight below the 10th percentile (p < 0.001), low Apgar scores at 5 minutes (p < 0.001), neonatal resuscitation (p < 0.001), intubation requirements (p < 0.001), prolonged NICU admission (p < 0.001), and a trend towards neonatal death (p = 0.070).

The diagnostic performance analysis comparing CPR with pulsatility indices of the umbilical artery (UA) and middle cerebral artery (MCA) further emphasized the superiority of CPR in predicting adverse perinatal outcomes. CPR exhibited higher sensitivity (97.6%) and specificity (91.8%) compared to UA and MCA pulsatility indices. Specifically, CPR showed higher sensitivity and comparable specificity to the UA pulsatility index while outperforming the MCA pulsatility index in both sensitivity and specificity. These results suggest that CPR may serve as a more reliable predictor of adverse perinatal outcomes in pregnancies complicated by suspected FGR.

Our findings align with previous research indicating the superior diagnostic performance of CPR compared to individual pulsatility indices of UA and MCA. The study by Khalil et al. ⁶ reported higher sensitivity and specificity of CPR in predicting adverse neonatal outcomes in FGR pregnancies. Additionally, the study by Cruz-Martínez et al. ⁵ highlighted the utility of CPR as a valuable tool for risk stratification in FGR pregnancies, corroborating our findings.

The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the CPR for predicting adverse perinatal outcomes in clinically suspected FGR pregnancies were evaluated and are summarized in Table 4.

Our study highlights the diagnostic superiority of CPR over UA PI and MCA PI in predicting adverse perinatal outcomes in FGR pregnancies. These findings underscore the potential of CPR as a valuable prognostic marker for guiding clinical decision-making and improving perinatal outcomes in high-risk pregnancies.