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

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.  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. 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). 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.