Association between routine anticoagulation and pregnancy outcomes in women with heterozygous Factor V Leiden genotype.

BACKGROUND: Inherited thrombophilia, particularly heterozygous Factor V Leiden (G1691A) mutation, has been linked to placental vascular complications and adverse pregnancy outcomes. However, the benefit of antenatal anticoagulation in affected women without prior venous thromboembolism remains uncertain. AIM: To assess the association between antenatal anticoagulant therapy and pregnancy outcomes in women carrying the heterozygous Factor V Leiden genotype with a history of adverse pregnancy outcomes. METHODS: This case-control study included 200 pregnant women with confirmed heterozygous Factor V Leiden (G1691A) genotype. Participants were divided into two groups: those who received antenatal anticoagulation (low-molecular-weight heparin with or without low-dose aspirin; n = 100) and those who did not (n = 100). Genotyping was performed using real-time PCR and confirmed by Sanger sequencing. Pregnancy outcomes were compared, and relative risk (RR) with 95% confidence intervals (CI) calculated. RESULTS: Both groups were comparable in baseline characteristics, including age, body mass index, and consanguinity (p > 0.05). Normal pregnancy outcomes were significantly higher in the anticoagulated group than controls (72% vs. 24%; p < 0.001). Anticoagulation was associated with a 2.7-fold higher likelihood of a normal pregnancy outcome (RR = 2.71, 95% CI: 1.94-3.78). Among adverse outcomes, only small for gestational age was significantly reduced (p = 0.02); other outcomes showed no significant differences. CONCLUSION: Antenatal anticoagulant therapy was associated with improved pregnancy outcomes in women with heterozygous Factor V Leiden genotype. These findings support a potential benefit of prophylactic anticoagulation; however, confirmation through large prospective randomized trials is required.