Prognostic Accuracy of Cerebroplacental Ratio, Use as A Predictive Tool in Earlier Assessment of Adverse Perinatal Outcome

Abstract

Objective: To determine the prognostic accuracy of the cerebroplacental ratio (CPR) as a predictive tool for the early assessment of adverse perinatal outcomes.

Methodology: This prospective observational cohort study was conducted on pregnant women with a gestational age between 28 and 40 weeks, having singleton high-risk pregnancies in the third trimester. Participants were recruited from the outpatient department (OPD) and inpatient wards of Dr. Ruth K. M. Pfau Civil Hospital, Karachi, from June 2020 to May 2021. Doppler ultrasound assessments were performed using a high-resolution Toshiba Xario 100 ultrasound machine to estimate the pulsatility index (PI) and resistance index (RI) of the umbilical artery (UA) and middle cerebral artery (MCA). The cerebroplacental ratio was calculated as the ratio of MCA-PI to UA-PI. Doppler examinations were reviewed by two experienced radiologists, and values below the 5th percentile for gestational age (approximately <1.08–1.1) were considered abnormal.

Results: The mean age of the participants was 29.15 ± 2.03 years, and the mean gestational age was 32.23 ± 3.09 weeks. Intrauterine death (IUD) occurred in 8 cases, birth asphyxia was observed in 29 cases, and one neonatal death was reported. Abnormal MCA RI, CPR RI, and CPR PI values were observed in 28.6%, 24.6%, and 24.6% of cases, respectively. Analysis of the correlation between Doppler indices and perinatal outcomes showed that abnormal MCA RI was significantly associated with intrauterine death and birth asphyxia (p = 0.001). Abnormal CPR RI values were also significantly associated with birth asphyxia (p = 0.001), while no significant association was observed between MCA PI and adverse fetal outcomes (p > 0.05).

Conclusion: The cerebroplacental ratio was found to be a useful indicator for the early detection of adverse perinatal outcomes.