The Predictive Value and Clinical Treatment Guidance of Uterine Artery Blood Flow Parameters for Recurrent Pregnancy Loss

Objective To investigate the relationship between uterine artery blood flow parameters (S/D, RI, PI, PSV) and the number of miscarriages, etiology, treatment methods, and pregnancy outcomes in patients with recurrent pregnancy loss (RPL). Methods A retrospective analysis was conducted on data from patients with RPL and women with normal pregnancy who visited Xinhua Hospital affiliated with Shanghai Jiao Tong University School of Medicine and the International Peace Maternity and Child Health Hospital between October 2017 and December 2024. The study observed various parameters of uterine artery blood flow, comparing differences in the number of miscarriages, causes, treatment methods, and pregnancy outcomes. Receiver Operating Characteristic (ROC) curves were used to evaluate the predictive value of blood flow parameters on pregnancy outcomes. Results The study included 652 patients with RPL and 432 pregnant women with normal pregnancy. 1) With increasing gestational age, the uterine artery systolic/end-diastolic velocity (S/D), pulsatility index (PI), and blood flow resistance index (RI) showed a downward trend in patients with normal pregnancy. 2) As the number of spontaneous miscarriages increased, the uterine artery blood flow S/D ratio and PI value gradually increased, while the Peak systolic velocity (PSV) and RI values showed no significant correlation with the number of miscarriages. 3) In RPL patients caused by immunological factors (APS, SLE, etc.), the uterine artery S/D ratio, PI, and RI values were significantly elevated. In contrast, in RPL patients caused by endocrine factors, although the S/D ratio, PI, and RI values also tended to increase, the magnitude of increase was much less compared to RPL caused by immunological factors. In patients with unexplained RPL (URPL), the uterine artery S/D ratio, PI, and RI values were also significantly elevated. In RPL patients due to chromosomal factors, the uterine artery blood flow parameters showed no significant difference compared to the normal group. 4) After treatment, the S/D, RI, and PI values significantly decreased (p < 0.05), and PSV increased (p < 0.05), suggesting a significant negative correlation between pre-treatment uterine artery S/D ratio, PI value, and pregnancy outcomes (p < 0.05). 5) Combined medication (aspirin + nifedipine + sildenafil citrate) was most effective, significantly reducing S/D, PI, and RI (p < 0.05), and markedly improving pregnancy outcomes (p < 0.05). 6) ROC analysis showed that S/D (AUC = 0.8385) and PI (AUC = 0.8130) had a high predictive value for adverse pregnancy outcomes, with optimal thresholds of 22.69 and 5.83, respectively. Conclusion Uterine artery blood flow parameters (particularly S/D and PI) can serve as predictive indicators of pregnancy outcomes in patients with RPL. Combined pharmacological treatment can significantly improve hemodynamics and reduce the risk of miscarriage.