Mutations in the factor V, prothrombin and MTHFR genes are not risk factors for recurrent fetal loss

Abstract

Our study did not demonstrate that women who are carriers of the factor V, prothrombin, or MTHFR mutations are at higher risk of recurrent fetal loss than women without these mutations. In regards to factor V Leiden, the prevalence in our cases (1.7%) was not statistically different from the known population prevalence of 5%. However, the high prevalence in our controls (14%) was unusual. Factor V Leiden may protect against bleeding in early pregnancy.

Thrombophilias and recurrent pregnancy loss: a critical appraisal of the literature

“…In the studies by Souza et al [44] and Foka et al [58], PTG was significantly more common among cases. The difference of the mutation reported by Dilley et al [74] did not reach statistical significance. However, Dilley et al used a study group with a history of all trimester losses and Foka et al used a study group with only first or second trimester losses.…”

“…Finally, the study performed by Dilley et al [74] reported a remarkable high prevalence of the factor V Leiden mutation in the controls: 14.1% as compared to 1.7% in the cases, which was a significant difference. Many factors were matched for among cases and controls, including BMI, smoking, hypertension, education and history of thrombosis.…”

“…None of the 39 cases had abnormal levels of one of these. Dilley et al [74] found significant lower plasma levels of antithrombin, protein C and protein S in the cases than in the controls, but the numbers of patients and controls with a deficiency in one of these were not described.…”

“…However, it is unlikely that this has influenced the results, since the prevalence did not differ significantly between cases and controls. In addition, Foka et al [58] and Dilley et al [74] did not observe significantly more MTHFR mutations in recurrent aborters.…”

Potential role of Factor V Leiden mutation in adverse pregnancy outcomes: An updated systematic review

“…It concluded that testing for these mutations in the initial screening of women with RPL and negative personal thromboembolic history was not cost-effective (Serrano et al, 2011). Similarly, in a controlled study, Dilley et al found the frequency of FVL to be similar in 60 women with RPL and 92 controls without a history of miscarriage (Dilley et al, 2002).…”