Maternal and neonatal outcome of preeclamptic pregnancies: the potential roles of factor V Leiden mutation and 5,10 methylenetetrahydrofolate reductase.

OBJECTIVE: To investigate the potential perinatal effects of Factor V Leiden mutation and 5,10 methylenetetrahydrofolate reductase C677T polymorphism in preeclamptic women. STUDY
DESIGN: One hundred twenty preeclamptic women (N = 120) and 101 healthy pregnant controls (N = 101) were recruited and evaluated for frequency of Leiden and 5,10 methylenetetrahydrofolate reductase (MTHFR) mutations using polymerase chain reaction (PCR). Perinatal outcomes were then recorded and analyzed for all study participants and their neonates.
RESULTS: Laboratory analysis yielded 22 (18.33%) heterozygous carriers of Factor V Leiden mutation among preeclamptic women and 3 (2.97%) heterozygous carriers among the healthy controls; differences between the two groups were found to be statistically significant [p < 0.001, the relative risk (RR) = 6.17, 95% confidence interval (95% CI) = 1.90-20.02]. Homozygous MTHFR mutations were found in 8 of 120 (6.67%) preeclamptic women and in 6 of the 101 (5.94%) healthy controls evaluated. Among preeclamptic women, episodes of hemolysis, elevated liver enzymes, and low platelet (HELLP) syndrome were reported in 7 of 22 (31.81%) of those with Factor V Leiden mutation and in 11 of 98 (11.22%) of those who were negative for the mutation. Group differences were determined to be statistically significant (p < 0.015, RR = 2.83, 95% CI = 1.24-6. 48). Perinatal indicators collected from the two groups included frequency of intrauterine growth retardation, birth weight, and gestational age. No statistically different perinatal outcomes were found between Factor V Leiden positive and negative preeclamptic women. In addition, MTHFR gene polymorphism did not appear to be correlated with the development of preeclampsia.
CONCLUSION: Although the frequency of Factor V Leiden mutation appears to be significantly higher among preeclamptic women, the mechanism of pathogenesis and potential influence on perinatal outcomes is not yet well understood. Relatively high rates of HELLP syndrome among those with Factor V Leiden mutation suggest that this thrombogene mutation may play a significant role in hemostatic system activation. Our results suggest that the role of MTHFR polymorphism and other factors such as folic acid supplementation will require more extensive analysis in controlling worldwide morbidity and mortality associated with this important maternal condition.