Abstract
This study aimed to determine changes in uterine artery Doppler parameters in unexplained recurrent pregnancy loss (URPL) and to explore serum markers possibly associated with them. This retrospective case-control study included 107 URPL women and 107 control women. The mean pulsatility index (PI), resistive index (RI), and systolic-to-diastolic values for uterine arteries in URPL women were significantly higher than those in the controls (P < 0.05). The cutoff values of PI and RI differentiating the women with URPL from the controls were confirmed by ROC and Youden's index. Given a PI cutoff value of 2.6, the prevalence of URPL was significantly elevated in the high-PI group (74.58%) compared with that in the low-PI group (40.65%, P < 0.0001), with sensitivity and specificity of 63% and 69%, respectively. With an RI cutoff value of 0.86, the prevalence of URPL in the high-RI group (65.28%) was significantly elevated compared with that in the low-RI group (42.25%, P = 0.001), with sensitivity and specificity of 66% and 75%, respectively. The levels of serum D-dimers and anticardiolipin antibody (ACA)-IgM in URPL women were significantly higher than those in the controls. A positive correlation existed between the levels of ACA-IgM and uterine artery RI in URPL women (r = 0.43, P < 0.01). These results indicated that URPL women may be at a relatively high risk of a prothrombotic state, and the increased ACA-IgM deserves attention for its role in the elevated uterine artery Doppler parameters in URPL women.