Doppler Evaluation of Uterine Blood Flow in Patients with Unexplained Recurrent Pregnancy Loss

This study aimed to analyze uterine artery and spiral artery hemodynamics in patients with unexplained recurrent pregnancy loss (URPL) with varying pregnancy outcomes.

174 pregnant women with URPL and 144 pregnant women without adverse pregnancy histories were enrolled in this retrospective study. Based on pregnancy outcomes, these patients were divided into two groups: normal pregnancy outcomes (URPL-N, n=138) and adverse pregnancy outcomes (URPL-A, n=36). Control group participants were categorized into normal pregnancy outcomes (CON-N, n=129) and adverse pregnancy outcomes (CON-A, n=15). We compared uterine artery and spiral artery hemodynamics during different stages of gestation and the predictive value of these parameters for pregnancy outcomes.

URPL-N group had fewer pregnancy losses and lower BMI compared to URPL-A group (P< 0.05). Spiral artery hemodynamics in URPL-N and CON-N groups were lower than those in URPL-A and CON-A groups during the mid-luteal phase, 11-13 weeks, 15-17 weeks, and 19-21 weeks of gestation, respectively. Uterine artery hemodynamics ((Pulsatility index (mPI), resistive index (mRI), and systolic-to-diastolic ratio (mS/D)) in the mid-luteal period were lower in URPL-N group than URPL-A group. Similarly, in CON-N group were lower than CON-A group. The URPL-A and CON-A groups had higher uterine artery and spiral artery hemodynamics when compared to the URPL-N and CON-N groups. Spiral artery hemodynamics exhibited larger areas under the ROC curve compared to uterine artery parameters.

Abnormal hemodynamics in these arteries may contribute to URPL and adverse pregnancy outcomes. Spiral artery hemodynamics are more reliable predictors of pregnancy outcomes than uterine artery parameters.