Objective To explore dynamic change rules of umbilical artery Doppler spectrum in fetal abdomen and its relationship with pregnancy outcomes of puerperae with hypertensive disorder complicating pregnancy (HDCP). Methods A total of 150 puerperae with HDCP undergoing pregnancy examination and delivery in the hospital were retrospectively analyzed between FebruaryS2018 and February 2022. According to diagnostic criteria of HDCP, they were divided into preeclampsia group (54 cases) and simple hypertension group (96 cases). A total of 50 healthy puerperae during the same period were enrolled as control group. The results of fetal Doppler ultrasound blood flow imaging in the second trimester (22-28 weeks) were collected. The blood flow related parameters of fetal umbilical artery [arterial pulsatility index (PI), resistance index (RI), peak-to-valley ratio of flow velocity (S/D)] and adverse pregnancy outcomes in different groups were compared. The correlation between umbilical artery blood flow-related parameters and the severity of HDCP was analyzed by Pearson correlation analysis. The predictive value of umbilical artery blood flow-related parameters for adverse pregnancy outcomes was analyzed by receiver operating characteristic (ROC) curves. Results PI, RI and S/D were the greatest in preeclampsia group, followed by simple hypertension group and control group (P<0.05). PI, RI and S/D of umbilical artery in the second trimester were all positively correlated with the severity of HDCP (r=0.268, 0.226, 0.350, 0.672, P<0.05). The overall incidence of adverse pregnancy outcomes in preeclampsia group and simple hypertension group was higher than that in control group (51.85% vs 12.00%, 28.72% vs 12.00%, P<0.05). The overall incidence of adverse pregnancy outcomes in preeclampsia group was higher than that in simple hypertension group (51.85% vs 28.72%, P<0.05). PI, RI and S/D in HDCP patients with adverse pregnancy outcomes were greater than those with good pregnancy outcomes (P<0.05). PI, RI and S/D in the second trimester were of predictive value for adverse pregnancy outcomes (AUC=0.736, 0.816, 0.808, 0.800, P<0.05). Conclusion The umbilical artery blood flow parameters (PI, RI, S/D) significant increase in the second trimester of HDCP, which increase with the malignant development of the disease. The umbilical artery blood flow parameters (PI, RI, S/D) increase in HDCP patients with adverse pregnancy outcomes in the second trimester, which can be applied as predictive indexes for adverse pregnancy outcomes.