THE FACTOR-V-LEIDEN MUTATION IS NOT A COMMON-CAUSE OF RECURRENT MISCARRIAGE

Some investigators suggest that placental thrombosis and infarction ca n cause recurrent miscarriage. We have shown that the common missense mutation in the factor V gene, the Leiden mutation, which renders fact or Va resistant to cleavage inactivation by activated protein C, predi sposes to placental thrombosis and spontaneous miscarriage. Our object ive was to determine the frequency of the Leiden mutation in a populat ion with well-characterized idiopathic recurrent miscarriage. DNA was extracted from whole blood of 40 couples with a history of idiopathic recurrent miscarriage and 25 couples with a history of proven fertilit y (seven or more live births). The polymerase chain reaction was used to amplify exon 10 of the factor V gene followed by allele-specific re striction with Mnl1 for mutation detection. Results were analyzed with a chi(2) contingency table. None of the 40 women with idiopathic recu rrent miscarriage carried the mutation and only one of their reproduct ive partners was heterozygous for the mutation. Similarly, none of the control women carried the mutation, and only one of the 25 control ma le partners was heterozygous for the mutation. In our referral populat ion, the factor V Leiden mutation which predisposes to thrombosis is n ot a common cause of recurrent miscarriage. (C) 1997 Elsevier Science Ireland Ltd.