519: Do antiphospholipid antibodies affect pregnancy outcomes in women heterozygous for Factor V Leiden?

Abstract

Antiphospholipid antibodies are associated with a spectrum of pregnancy complications, including preeclampsia (PE) and small for gestational age (SGA) fetuses. Our goals were to assess the frequency of elevated levels of anticardiolipin (aCL) and anti-2-glycoprotein I (anti-2-GPI) IgG and IgM antibodies in women with and without the Factor V Leiden (FVL) mutation and to examine if interactions between the FVL mutation and aCL and anti-2-GPI antibodies alter the rates of PE and SGA. Secondary analysis of a multicenter, prospective observational study of FVL prevalence among 5188 pregnant women. 371 women (120 cases of FVL heterozygotes and 251 FVL mutation negative randomly selected controls [matched for clinical center, maternal age, and race/ethnicity]) underwent serum analysis for the presence of aCL and anti-2-GPI IgG and IgM. The primary outcome was development of PE and/or SGA (<10%). Forty seven women (12.7%) developed the primary outcome; there were no differences in primary outcome rates between women with and without antiphospholipid antibodies, regardless of FVL mutation status. Among FVL carriers, antiphospholipid antibody status does not appear to contribute to adverse pregnancy outcome.