The Pregnancy In Women With
Antiphospholipid Syndrome study is a multicenter, retrospective, cohort study. Diagnosis and classification of
antiphospholipid syndrome were based on the 2006 International revised criteria. All women included in the study had at least 1 clinical criteria for
antiphospholipid syndrome, were positive for at least 1
antiphospholipid antibody (
anticardiolipin antibodies, anti-β2
glycoprotein-I, and/or
lupus anticoagulant), and were treated with low-dose
aspirin and prophylactic
low molecular weight heparin from the first trimester. Only singleton pregnancies with primary
antiphospholipid syndrome were included. The primary outcome was live birth, defined as any delivery of a live infant after 22 weeks gestation. The secondary outcomes were
preeclampsia with and without severe features,
intrauterine growth restriction, and
stillbirth. We planned to assess the outcomes that are associated with the various antibody profile (test result for
lupus anticoagulant,
anticardiolipin antibodies, and anti-β2
glycoprotein-I).
RESULTS: There were 750 singleton pregnancies with primary
antiphospholipid syndrome in the study cohort: 54 (7.2%) were positive for
lupus anticoagulant only; 458 (61.0%) were positive for
anticardiolipin antibodies only; 128 (17.1%) were positive for anti-β2
glycoprotein-I only; 90 (12.0%) were double positive and
lupus anticoagulant negative, and 20 (2.7%) were triple positive. The incidence of live birth in each of these categories was 79.6%, 56.3%, 47.7%, 43.3%, and 30.0%, respectively. Compared with women with only 1 antibody positive test results, women with multiple antibody positive results had a significantly lower live birth rate (40.9% vs 56.6%; adjusted odds ratio, 0.71; 95% confidence interval, 0.51-0.90). Also, they were at increased risk of
preeclampsia without (54.5% vs 34.8%; adjusted odds ratio, 1.56; 95% confidence interval, 1.22-1.95) and with severe features (22.7% vs 13.8%, adjusted odds ratio, 1.66; 95% confidence interval, 1.19-2.49), of
intrauterine growth restriction (53.6% vs 40.8%; adjusted odds ratio, 2.31; 95% confidence interval, 1.17-2.61) and of
stillbirth (36.4% vs 21.7%; adjusted odds ratio, 2.67; 95% confidence interval, 1.22-2.94). In women with only 1 positive test result, women with anti-β2
glycoprotein-I positivity present alone had a significantly lower live birth rate (47.7% vs 56.3% vs 79.6%; P<.01) and a significantly higher incidence of
preeclampsia without (47.7% vs 34.1% vs 11.1%; P<.01) and with severe features (17.2% vs 14.4% vs 0%; P=.02),
intrauterine growth restriction (48.4% vs 40.1% vs 25.9%; P<.01), and
stillbirth (29.7% vs 21.2% vs 7.4%; P<.01) compared with women with
anticardiolipin antibodies and with women with
lupus anticoagulant present alone, respectively. In the group of women with >1 antibody positivity, triple-positive women had a lower live birth rate (30% vs 43.3%; adjusted odds ratio,0.69; 95% confidence interval, 0.22-0.91) and a higher incidence of
intrauterine growth restriction (70.0% vs 50.0%; adjusted odds ratio,2.40; 95% confidence interval, 1.15-2.99) compared with double positive and
lupus anticoagulant negative women.
CONCLUSION: