Antiphospholipid Antibodies in In vitro Fertilisation: Pathogenesis, Implantation Failure and Emerging Therapeutic Strategies

Infertility, defined as an inability to get pregnant following 12 months of regular, unprotected intercourse, is a significant problem, and 15% is unexplained. Autoimmune conditions such as anti-phospholipid syndrome (APS) and systemic lupus erythematosus cause infertility by altering implantation by thrombophilic mechanisms and immune derangement. Despite progress in assisted reproductive technologies, implantation failure continues to be a strong hindrance, determined by maternal health, immune tolerance and endometrial receptivity. Antiphospholipid antibodies (aPLs) compromise trophoblast function, enhance thrombosis risk and account for in vitro fertilisation (IVF) failure, recurrent pregnancy loss and pregnancy complications. A review of 45 peer-reviewed articles published over the past 8 years was performed on PubMed, Scopus, Web of Science and Google Scholar. MeSH terms used were 'antiphospholipid syndrome', 'in vitro fertilization', and 'infertility'. Non-English publications, case reports, editorials and conference abstracts were not included. Results suggest that APS and aPL inhibit implantation due to trophoblast malfunction, inflammation and thrombosis, causing infertility and recurrent pregnancy loss. In IVF, aPL correlates with reduced rates of implantation and live birth, with various subtypes of antibodies predicting adverse outcomes. Traditional therapies such as low-dose aspirin and low-molecular-weight heparin are routine, whereas novel therapies such as intravenous immunoglobulin, rituximab and eculizumab hold promise for resistant disease. Due to the inconclusive effect of aPL on IVF success, individualised risk stratification and focused anticoagulation regimens are important for maximising reproductive outcomes.