Prospective studies of the association between anticardiolipin antibody and outcome of pregnancy

To investigate the association of anticardiolipin antibody with the genesis of spontaneous abortion, fetal growth restriction (FGR), and preeclampsia. Eight hundred sixty pregnant women constituted the study population. Anticardiolipin antibody was screened by enzyme-linked immunosorbent assay during the first trimester of pregnancy. The outcome of pregnancy in these women was analyzed prospectively, and the rate of occurrence of spontaneous abortion, preeclampsia, and FGR was compared in the anticardiolipin antibody-positive and -negative groups. Anticardiolipin antibody was positive in 60 of the 860 women (7.0%) and negative in 800 (93.0%). The rate of spontaneous abortions in the anticardiolipin antibody-positive group, 25.0%, was significantly higher than that in the anticardiolipin antibody-negative group, at 9.8% (P < .001; relative risk [RR] 2.56, 95% confidence interval (CI) 1.37–4.81). The rates of preeclampsia (11.7%) and FGR (11.7%) in the anticardiolipin antibody-positive group were also significantly higher than those in the -negative group (1.9 and 1.9%, respectively; for preeclampsia, P < .001; RR 6.22, 95% CI 2.43–16.0 and for FGR, P < .001; RR 6.22, 95% CI 2.43–16.0). Anticardiolipin antibody is associated with adverse outcomes of pregnancy such as spontaneous abortion, preeclampsia, and FGR.