Recurrent Miscarriage and Low-titer Antiphospholipid Antibodies

Objective: To evaluate the clinical features and pregnancy outcomes in patients experiencing recurrent miscarriage (RM) with either low-titer or medium-high titer positivity of antiphospholipid antibodies (aPL).

Methods: A retrospective review of medical records was conducted for patients with aPL positivity and recurrent miscarriage between 2018 and 2022. The clinical features, treatment strategies, outcomes were compared between the patients with low (n = 92) and medium (n = 32) titer of aPL.

Results: A total of 118 patients, resulting in 124 obstetric episodes (pregnancies), with a mean age of 33. 15 ± 4.56 and 31.47 ± 4.41 years between the two groups. The low-titer group exhibited a higher frequency of anti-cardiolipin antibodies IgM (P < 0.001), whereas the medium-high titer group demonstrated a higher frequency of anti-β2-glycoprotein 1 antibodies IgG (P < 0.001) and IgM (P = 0.032). Moreover, the medium-high titer group displayed a significantly elevated erythrocyte sedimentation rate compared to the low-titer group (P < 0.05). In the low-titer group, 71 patients (77.2%) received appropriate treatment, resulting in 48 live births (67.6%) and 23 repeat abortions (32.4%). In the medium-high titer group, 29 patients (90.6%) received relevant treatment, leading to 23 live births (79.3%) and 6 repeat abortions (20.7%). No significant differences were observed in live births or maternal-fetal complications between the two groups (all P > 0.05).

Conclusion: Noteworthy distinctions in laboratory parameters were identified between the low-titer and medium-high titer groups. However, when appropriately treated, the fetal-maternal outcomes were comparable in both groups. Timely intervention by clinicians is imperative to enhance pregnancy outcomes in patients experiencing recurrent miscarriage with low levels of aPL. Key Points • This study challenges the conventional belief that only the higher antiphospholipid antibodies (aPL) titers directly correlated with worse pregnancy outcomes, which emphasized the importance of patients with low titer positive aPL-positive RM. • The results underscore the need for timely intervention in women with low titer aPL-positive RM, as it leads to favorable maternal-fetal outcomes.