Activated protein C resistance - In the absence of factor V Leiden - And pregnancy

Abstract

Background: Activated protein C (APC) resistance with or without factor V Leiden (FVL) is amajor risk factor for venous thromboembolism. Many previous pregnancy studies have been focused on APC resistance caused by FVL. Very few have investigated APC resistance in the absence of FVL (APCRFVL-). Material and methods: In a prospective study of 2480 unselected gravidae, blood was drawn in early pregnancy (mean = 12 weeks of gestation). APC resistance was analyzed by an APTT-based method (Coatest® APC-resistance) and the presence of FVL was determined by PCR. The APCRFVL- group had similar mean APC resistance ratio as the heterozygous carriers of FVL. The analyseswere carried out no earlier than 3 months after delivery when all data were recorded. Small-for-gestational age (SGA) was used as a proxy for intrauterine growth restriction. Results: When compared with the control group, women with APCRFVL- had no increased risk of SGA, pre-eclampsia,.rst trimester fetal loss or venous thromboembolism. However, they had an increased risk of second trimester fetal loss (7.3% vs. 2.7%, P = 0.01), and a tendency of being overweight (17.3% vs. 12.6%, P = 0.19) and of delivering extremely preterm (2.8% vs. 1.0%, P = 0.11). Conclusion: Women with APC resistance not caused by FVL were not at increased risk for SGA, pre-eclampsia, .rst trimester fetal loss, or abnormal blood loss. However, they showed an increased prevalence of second trimester fetal loss. © 2006 International Society on Thrombosis and Haemostasis.