Pathology findings in preterm placentas of women with autoantibodies: a case-control study.

Objective: To evaluate the placental histopathology findings in women with systemic lupus erythematosus or antiphospholipid syndrome delivered preterm.

Methods: We performed a case-control study comparing clinical outcomes and placental histopathology of 18 consecutive singleton pregnancies with systemic lupus erythematosus (n = 9) or antiphospholipid syndrome (n = 9) delivered between 24 and 37 weeks, and 54 controls matched for gestational age and type of preterm delivery (spontaneous or indicated). Placental examinations were performed by a single pathologist, and placental lesions were grouped into four categories: uteroplacental vascular pathology and related villous lesions; coagulation-related damage; chronic inflammation; and acute inflammatory lesions. Statistical analysis included the Mantel-Haenzsel or Fisher's exact test, and logistic regression, with a value of p < 0.05 or an odds ratio (OR) with 95% confidence intervals (Cl) not inclusive of unity considered significant.

Results: Lupus anticoagulant was positive in ten out of 18 cases and medium or high positive IgG anticardiolipin antibodies in seven out of 18. Antenatal treatment included corticosteroids (n = 9), low-dose aspirin (n = 15) and heparin (n = 8). Rates of necrotizing enterocolitis (33% vs. 0%, p < 0.001) and of perinatal mortality (33% vs. 9%, p = 0.02) were significantly different between cases and controls, and rates of birth weight < 10th centile approached statistical significance. Uteroplacental vascular lesions (OR 3.7, 95% CI 1.1, 11.7) and coagulation-related damage (OR 16.8, 95% CI 3.9, 72.6) were significantly more common among cases than controls, and rates of chronic inflammatory lesions approached significance.

Conclusions: Cases of systemic lupus erythematosus and antiphospholipid syndrome delivered preterm are associated with a significant increase in placental vascular and coagulation-related lesions, which are reflected clinically by higher rates of perinatal mortality, necrotizing enterocolitis, and small-for-gestational age neonates.