Evaluation of risk factors in a large cohort of patients with recurrent miscarriage

Objective: The aim of this study was to identify the prevalence of risk factors for RM in a large study group.

Methods: In total, n = 590 RM patients recruited between 03/2012 and 08/2015 underwent standardized diagnostics including screening for (i) anatomical malformations, (ii) endocrine dysfunctions (follicular and luteal phase), (iii) autoimmune disorders (antinuclear antibodies (ANA), anti- cardiolipin antibodies (ACL IgG/IgM), anti-ß2-glycoprotein ß2-IgG/IgM, lupus anticoagulant (LA)), (iv) prothrombotic changes (mutations in the factor V Leiden (FVL), prothrombin (PT), MTHFR gene, deficiencies of protein C/S, antithrombin (AT)) and (v) parental chromosomal disorders. Out of these, n = 268 patients with ≥3 consecutive miscarriages were identified and included in this study.

Results: Patients characteristics: age 34.6 ± 2.8 years (mean ± standard deviation), BMI 24.5 ± 4.4, n = 85 secondary RM. Anatomical malformation were observed in 7.8% (n = 21). Endocrine dysfunctions were present in 46.6% (n = 125; n = 104 luteal phase deficiency, n = 29 thyroid dysfunction). Autoimmune disorders were found in 31.3% (n = 84; n = 23 ACL or ß2 IgG/IgM, n = 69 ANA > 1:160). In total 23.1% (n = 62) suffered from prothrombotic changes. Parental chromosomal aberrations were found in 5.8% (n = 14) RM patients. Most of the RM patients (n = 149, 56%) remained idiopathic (iRM).

Conclusion: The largest subpopulation consisted of iRM patients. There was a high prevalence for endocrine as well as autoimmune disorders. However, the impact of luteal phase deficiency as well as elevated ANA levels on the pathophysiology of RM is discussed controversial.