BackgroundRecurrent pregnancy loss (RPL) affects up to 5% of pregnancies, but with no consensus on the definition. Inherited thrombophilia has been postulated as a risk factor for RPL. The aim of this study was to investigate the association of RPL with polymorphisms of five genes that influent the coagulation and fibrinolysis.MethodsThis study was conducted on total of 224 women, 129 women with ≥2 early RPL or ≥1 late pregnancy loss, 95 women with at least two normal life births and no history of pregnancy loss. Five gene polymorphisms F2 20 210G>A (rs1799963), F5 1691G>A (rs6025), MTHFR 677C>T (rs1801133), SERPINE1 −675 4G/5G (rs1799762) and ACE I/D (rs1799752) were genotyped by PCR-based methods.ResultsA significant relationship was found between SERPINE1 4G/4G and ACE D/D polymorphisms and RPL (p<0.001 both, OR 2.91 and 3.02, respectively). In contrast, no association was found between F2 20 210G>A, F5 1691G>A and MTHFR 677C>T polymorphisms and risk for RPL. A combination of hypofibrinolytic homozygotes SERPINE1 4G/4G+ACE D/D was observed as a highly associated with RPL (Cochran-Armitage test, p<0.001), and their strong independent association with RPL risk was confirmed by logistic regression analysis (both p values <0.001, OR 3.35 and 3.43, respectively).ConclusionOur data have demonstrated that SERPINE1 and ACE gene polymorphisms, individually or in combination, appear to be a significant risk for RPL. This data may be useful in adding to the knowledge on inherited thrombophilia as an important contributor to RPL pathogenesis.