Objective To investigate the predictive value of color Doppler ultrasound parameters for fetal growth restriction (FGR) induced by hypertensive disorders of pregnancy in high-altitude regions.

Methods Pregnant women with gestational hypertension who were treated between July 2020 and June 2022 at the Affiliated Hospital of Qinghai University (with altitude of 2, 300 meters, were divided into group A1 with 19 cases and group A2 with 51 cases according to occurrence of FGR), Yushu People's Hospital (with altitude of 3, 700 meters, were divided into group B1 with 25 cases and group B2 with 47 cases according to occurrence of FGR), and Civil Aviation Clinical Medical College of Peking University (plain region, control group with 71 cases) were enrolled in this study. All pregnant women in each group underwent fetal color Doppler ultrasound examination of the middle cerebral artery (MCA) and umbilical artery (UA) blood flow parameters, including pulsatility index (PI), resistance index (RI), systolic/diastolic ratio (S/D), peak systolicvelocity (PSV), and cerebroplacental ratio (CPR) at 28 weeks of gestation were detected. Multivariate Logistic regression analysis was performed to identify independent risk factors for FGR in pregnant women with gestational hypertension. Receiver operating characteristic (ROC) curves were plotted to analyze the predictive value of color Doppler parametersfor FGR.

Results The UA blood flow parameters (PI, RI, S/D, PSV) of the fetuses in groups A1, A2, B1, and B2 were significantly higher than those in the control group, while the MCA blood flow parameters (PI, RI, S/D, PSV) and CPR were significantly lower (P < 0.05). Among the five groups, group B1 had the highest UA blood flow parameters (PI, RI, S/D, PSV) and the lowest MCA blood flow parameters (PI, RI, S/D, PSV) and CPR (P < 0.05). Multivariate Logistic regression analysis revealed that high altitude of residence and umbilical cord abnormalities were independent risk factors for FGR in pregnant women with gestational hypertension (P < 0.05). ROC curve analysis showed that the areas under the curves for the combined prediction of FGR in pregnant women with gestational hypertension at altitudes of 2, 300 meters and 3, 700 meters using color Doppler multi-parameters were 0.906 and 0.917, respectively, indicating a significantly higher predictive performance compared to individual parameter (P < 0.05).

Conclusion Color Doppler ultrasound parameters of UA and MCA bloodflow during the second trimester of pregnancy demonstrate good predictive value for FGR induced by hypertensive disorders of pregnancy in high-altitude regions at different altitudes, and the predictive performance is even higher when multiple parameters are combined.