The Role of Cerebro-placental Ratio in Determining Fetal Outcomes in Gestational Hypertension: An Institutional-based Study

Abstract

Aim: This prospective longitudinal study investigated the predictive value of the cerebro-placental ratio (CPR) for perinatal outcomes in pregnancies complicated by gestational hypertension. Study Location and Duration: This study was conducted at the Lagos State University Teaching Hospital in Nigeria from May 2019 to February 2020. Methodology: The study is a prospective longitudinal design. It included 110 pregnant women with gestational hypertension (97 of which had mild disease and 13, severe disease), matched for maternal and gestational ages with 110 normotensive controls. Both groups underwent ultrasound Doppler velocimetry to determine pulsatility indexes of the Middle Cerebral Artery (MCA) and Umbilical Artery (UA), from which the CPR was calculated. Participants were monitored until delivery, and both descriptive and inferential statistics were used to analyze data and evaluate the predictive accuracy of CPR for adverse perinatal outcomes. Results: This showed that gestational hypertension was most prevalent among primigravidae aged 26–30 years. The mean maternal age was approximately 30 years. Both groups had similar mean gestational ages at recruitment and delivery. Median values for MCA-PI, UA-PI, and CPR were comparable in controls and cases {1.5 (1.1, 1.8), 0.9 (0.7, 1.3) and 1.5 (1.1, 1.9) versus 1.5 (1.2, 1.9), 1.0 (0.8, 1.3) and 1.4 (1.0, 1.9)}, with no statistically significant differences (P value= 0.978, 0.326 and 0.443 respectively). Most participants in both groups had a CPR greater than 1. Adverse perinatal outcomes occurred in 33 hypertensive cases versus 18 normotensive controls. In terms of predictive accuracy for adverse outcomes, MCA-PI had a sensitivity of 50% and specificity of 53%; UA-PI had a sensitivity of 57% and specificity of 35%; CPR demonstrated a sensitivity of 50%, specificity of 57%, and a negative predictive value of 89.7%. Conclusion:  CPR was found to be normal in cases of mild gestational hypertension and did not differ significantly from normotensive pregnancies. Although CPR showed limited predictive accuracy for adverse perinatal outcomes in both groups, it may have greater value in pregnancies complicated by severe gestational hypertension. This study had a smaller number of women with severe hypertension which may have influenced findings. This is a study limitation; thus, larger studies are recommended.