Correlation Between Serum Markers and Midluteal Phase Doppler Assessment of Uterine Arterial Blood Flow in Unexplained Recurrent Pregnancy Loss

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.