Objective To investigate the application value of ultrasound microvascular imaging in monitoring placental blood perfusion and predicting pregnancy outcomes in late pregnancy with pregnancy-induced hypertension.

Methods A retrospective analysis was conducted in 150 pregnant women with pregnancy-induced hypertension in late gestation(study group), and another 150 pregnant women with normal pregnancy outcomes in late gestation during the same period were selected as control group. Both groups underwent ultrasound microvascular imaging, and the peak systolic velocity to end diastolic velocity ratio(S/D), pulsatility index (PI), resistance index (RI), vascularization index (VI) of the placenta, and the Apgar score at 1 minute after birth were recorded. Based on the severity of the disease, the study group was further divided into mild group (63 cases), moderate group (49 cases), and severe group(38 cases). According to the occurrence of adverse pregnancy outcomes, the study group was further divided into poor prognosis group (47 cases) and good prognosis group (103 cases). Receiver operating characteristic (ROC) curves were plotted to analyze the predictive value of each indicator for adverse pregnancy outcomes in pregnant women with pregnancy-induced hypertension.

Results The S/D, PI, and RI were higher in the study group than in the control group, while the VI and Apgar scores were lower in the study group (P < 0.05). There were statistically significant differences in S/D, PI, RI, VI, and Apgar scores among pregnant women with different severities of pregnancy-induced hypertension (P < 0.05). The S/D, PI, and RI were higher in the poor prognosis group than in the good prognosis group, while the VI and Apgar scores were lower in the poor prognosis group (P < 0.05). ROC curve analysis showed that the areas under the curve (AUCs) for predicting adverse pregnancy outcomes by S/D, PI, RI, VI, and Apgar scores were 0.741, 0.700, 0.738, 0.774, and 0.680, respectively (P < 0.05).

Conclusion Placental blood perfusion decreases significantly in late pregnancy with pregnancy-induced hypertension, and ultrasound microvascular imaging parameters, especially VI, can effectively assist in clinically assessing pregnancy outcomes.