ARG(506)-GLN MUTATION IN FACTOR-V AND RISK OF THROMBOSIS DURING PREGNANCY

Seventy women with thrombosis in pregnancy were investigated for the p resence of APC resistance and the associated Arg(506)-Gln mutation in coagulation factor V. The mutation was found in 46% of the investigate d women. Carriers of the mutation were more prone to develop thrombosi s in the first pregnancy (OR (odds ratio) = 3.41; P < 0.05) and had a higher probability of recurrence (OR = 3.86; P < 0.05) compared to non -carriers. The incidence of miscarriage was not related to the mutatio n but its probability increased in women with thrombosis in a second o r subsequent pregnancy (P < 0.025). Negative dynamics of APC response during pregnancy was observed in 20/22 women; eight of them developed APC resistance de novo. The suppression of APC response was independen t of the mutation.