Recurrent Miscarriage and Implantation Failure of Unknown Cause Studied by a Panel of Thrombophilia Conditions: Increased Frequency of FXIII Val34Leu Polymorphism

Background: The role of acquired thrombophilia has been accepted as an etiology of recurrent miscarriage (RM); however, the contribution of specific inherited thrombophilic genes to this disorder has remained controversial. An increased incidence of RM has been suggested in women with inherited thrombophilia. Methods: In this prospective study, assisted women with RM or repeated implant failure (RIF) were subjected to Thromboincode analysis, in order to identify 12 genetic variants for Factor V Leiden, Factor V Hong Kong, Factor V Cambridge, FII, FXIII, FXII, and A1 carriers. Patients included in this study were separated in RM cases (n=43), RIF cases (n=36) and RIF+RM (n=76). As a control group, patients undergoing IVF treatment (n=34) were used and a previously described 249 cases population as a representative sample of Spanish population were selected. Level of statistical significance was p<0.05 and groups were compared by Fisher test, except for age that was compared by t-test. Results: Regarding FXIII, higher values were observed in RM (69.76%), RIF (70%) and in RM+RIF (68.42%) group when compared with our control group (52.94%) and general Spanish population (56.5%), but these differences were statistically significant only in RIF group (p=0.043, p=0.01). Conclusion: Concerning our findings, both RM and RIF patients had a very similar panel of thrombophilia polymorphisms, suggesting that, in both, thrombophilia might have an important contribution. High frequency of Val34Leu polymorphism in RM/ RIF presumably speaks in favor of a multifactorial RM genesis, wherean altered thrombophilia status plays a role.