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

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.

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.

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.

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.

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.