The Cerebroplacental–Renal Ratio as a Novel Doppler-Based Marker of Adverse Perinatal Outcome in Pregnancy-Induced Hypertension

Background and Objectives: To evaluate the association between the newly defined cerebroplacental–renal ratio (CPRR) and adverse perinatal outcome (APO) in pregnancy-induced hypertension (PIH), and to compare its discriminative performance with the cerebroplacental ratio (CPR) and cerebroplacental–uterine ratio (CPUR). Materials and Methods: This prospective, single-center cohort study included 105 women with PIH (preeclampsia, n = 63; gestational hypertension, n = 42). Doppler assessment was performed at ≥34 + 0 weeks and within 7 days before delivery. CPR was calculated as middle cerebral artery pulsatility index (PI)/umbilical artery PI, CPUR as CPR/mean uterine artery PI, and CPRR as CPR/right renal artery PI. APO was defined by the presence of any of the following: non-reassuring fetal status, a 5 min Apgar score <7, neonatal intensive care unit admission, or neonatal death. Receiver operating characteristic analysis and multivariable logistic regression adjusted for gestational age at ultrasound assessment and diagnosis group were performed. Results: APO occurred in 37 pregnancies (35.2%). CPUR and CPRR were significantly lower in the APO group, whereas CPR did not differ significantly. CPRR showed a higher apparent AUC for APO than CPR and CPUR (AUC 0.786, 95% CI 0.698–0.875), with significantly higher AUCs on pairwise DeLong comparisons. After adjustment, CPRR was the only Doppler index independently associated with APO (adjusted OR 1.423 per 0.1-unit decrease; 95% CI 1.162–1.743; p = 0.001). Conclusions: CPRR was independently associated with APO in PIH and showed higher discriminative performance than CPR and CPUR; however, these findings require validation in independent, multicenter studies before clinical application.