Predictive value of fetal middle cerebral artery blood flow changes based on color Doppler ultrasonography for adverse pregnancy outcomes in patients with hypertensive disorders of pregnancy complicated by preeclampsia

Objective This study was aimed to evaluate the association and discriminatory performance of fetal middle cerebral artery (MCA) Doppler indices for adverse pregnancy outcomes in women with hypertensive disorders of pregnancy (HDP) complicated by preeclampsia (PE). Methods A total of 218 pregnant women who had undergone delivery at the hospital during the period from January 2023 through December 2025 were included in this retrospective analysis. The participants were categorized into three distinct groups: normal control (NC) group (n = 90), HDP group (gestational hypertension or chronic hypertension, n = 73), and HDP + PE group (gestational hypertension with PE and chronic hypertension with superimposed PE, n = 55). Fetal MCA hemodynamic indices were measured via ultrasonographic examination, and documentation of all adverse pregnancy outcomes was carried out systematically. To determine the independent factors associated with adverse pregnancy outcomes among patients in the HDP + PE group, logistic regression modeling was performed. Furthermore, receiver operating characteristic (ROC) curves were constructed to assess the predictive performance of the aforementioned MCA-derived ultrasonographic parameters. Results Compared with the NC group, both the HDP group and the HDP + PE group exhibited markedly elevated pre-pregnancy body mass index (BMI), systolic and diastolic blood pressures, while gestational week at delivery, newborn birth weight, and Apgar scores at 1 and 5 min were all notably reduced (all P < 0.05); these alterations were even more pronounced in the HDP + PE group (all P < 0.05). Ultrasonographic measurements demonstrated that fetal MCA pulsatility index (PI), resistance index (RI), and systolic-to-diastolic ratio (S/D) values in the HDP and HDP + PE groups were consistently diminished relative to those recorded in the NC group, with the most substantial reductions observed in the HDP + PE group (all P < 0.05). The HDP + PE group registered a total adverse pregnancy outcome rate of 61.82%, which was substantially greater than the corresponding rates in the HDP group (28.77%) and the NC group (11.11%) ( P < 0.05). Both univariate and multivariable logistic regression analyses demonstrated that pre-pregnancy BMI, systolic blood pressure, history of prior miscarriage, gestational age at MCA examination, and MCA-derived PI, RI, and S/D were independently associated with adverse pregnancy outcomes in patients with HDP and concurrent PE ( P < 0.05). The characteristic curve analysis further revealed that the area under the curve (AUC) values of MCA PI, RI, and S/D predicting adverse pregnancy outcomes were 0.739 (0.678–0.810), 0.760 (0.693–0.836), and 0.741 (0.685–0.829), respectively. Conclusion Color Doppler ultrasonography showed that fetal MCA blood flow parameters (PI, RI, and S/D) were significantly reduced in patients with HDP complicated by PE, and these reductions were independently associated with adverse pregnancy outcomes. MCA PI, RI, and S/D showed moderate discrimination for the composite adverse pregnancy outcome, supporting further evaluation of these indices as adjunctive markers for perinatal risk assessment, but their clinical thresholds still require further validation.