Thrombophilic gene mutations and recurrent spontaneous abortion: prothrombin mutation increases the risk in the first trimester.

PROBLEM: Thrombophilic predisposition may be one of the underlying causes of recurrent spontaneous abortions (RSA). We studied the prevalence of five thrombophilic gene mutations in patients with RSA. METHOD OF STUDY: 102 patients with two or more consecutive abortions and 128 women without miscarriage were analyzed for factor V Leiden mutation (FVL), prothrombin G20210A mutation (PTM), C677T mutation in the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene, glycoprotein IIIa (GPIIIa) C1565T polymorphism, and beta-fibrinogen G-455A polymorphism by polymerase chain reaction (PCR) techniques. RESULTS: No differences in the prevalence of FVL, MTHFR T/T, GPIIIa and 1-fibrinogen polymorphism were detected. Heterozygous PTM occurred more often in patients with RSA. This effect was significant in a subgroup with abortions exclusively in the first trimester (6.7%, vs. 0.8%, P = 0.027, OR 8.5). CONCLUSIONS: In contrast to the other mutations and polymorphisms, heterozygous PTM is more common in patients with abortions in the first trimester. This might reflect an influence of PTM on pathogenesis of early pregnancy loss.