High risk of adverse pregnancy outcomes in women with a persistent lupus anticoagulant.

Lupus anticoagulant (LA) has been associated with pregnancy complications and pregnancy loss. Identification of predictive factors could aid in deciding on therapeutic management. To identify risk factors for adverse pregnancy outcomes in high-risk women with persistently positive LA, we prospectively followed 82 women of childbearing age, of whom 23 had 40 pregnancies within the Vienna Lupus Anticoagulant and Thrombosis Study. Pregnancy complications occurred in 28/40 (70%) pregnancies, including 22 (55%) spontaneous abortions (<10th week of gestation [WOG]: n = 12, 10th to 24th WOG: n = 10) and 6 deliveries <34th WOG (15%, 3 due to severe preeclampsia/HELLP [hemolysis, elevated liver enzymes, and a low platelet count] syndrome, 3 due to placental insufficiency). One abortion was followed by catastrophic antiphospholipid syndrome. Neither a history of pregnancy complications nor of thrombosis, or prepregnancy antiphospholipid antibody levels were associated with adverse pregnancy outcomes. In logistic regression analysis, higher age was associated with a lower risk of adverse pregnancy outcome (per 5 years' increase: odds ratio [OR] = 0.41, 95% confidence interval [CI]: 0.19-0.87), a high Rosner index (index of circulating anticoagulant) predicted an increased risk (OR = 4.51, 95% CI: 1.08-18.93). Live birth rate was 15/28 (54%) in women on the combination of low-molecular-weight heparin and low-dose aspirin and 3/12 (25%) in those with no treatment or a single agent. We conclude that the risk of severe, even life-threatening pregnancy complications and adverse pregnancy outcomes is very high in women with persistent LA. A high Rosner index indicates an increased risk. Improved treatment options for women with persistently positive LA are urgently needed.