Influence of Antiphospholipid Antibody-Associated Thrombophilia on the Risk of Preterm Birth: A Systematic Review

Antiphospholipid antibody (aPL)-associated thrombophilia has been implicated in various adverse pregnancy outcomes, including preterm birth and impaired fetal development. This systematic review aimed to elucidate the relationship between aPL-associated thrombophilia and these outcomes, as well as to identify potential modifiers of this relationship such as maternal age, coexisting maternal medical conditions, type of aPL antibodies involved, and the timing of thrombophilia diagnosis during gestation. We conducted a comprehensive literature search in PubMed, Web of Science, Cochrane, and Scopus in May 2023, covering literature published within the last 10 years. Eight articles, involving 2935 patients, were eligible for inclusion in the review. Single aCL was the most common type of aPL found in patients, with rates up to 61.0% in some studies, followed by single LA and single ab2GPI. Multiple aPL antibody positivity was found to be associated with a higher risk of preterm birth, with odds ratios ranging from 1.29 to 9.61. Patient characteristics and previous pregnancy history varied significantly across the studies. Risk factors such as diabetes mellitus, thrombosis, and systemic lupus erythematosus were also variable across the studies, but presence of these risk factors did not consistently affect the risk of preterm birth. Furthermore, although a triple positive aPL test was the most important risk factor for preterm birth, it was observed that thrombophilia treatment during pregnancy significantly reduced the risk by 2.44 times (95% CI = 1.18-6.20). This review supports the evidence for aPL-associated thrombophilia being a significant contributor to preterm birth and fetal developmental abnormalities. Further research is required to investigate the exact mechanisms and to determine the best clinical management for patients with aPL-associated thrombophilia during pregnancy.