Autoimmune disease in pregnancy. Systemic lupus erythematosus and antiphospholipid syndrome

Autoimmune diseases occur most commonly in women of childbearing age. Over 70% of individuals with autoimmune diseases are women, though some conditions (e.g., ankylosing spondylitis) are more common in men. Many authorities have focused on sex hormones as an explanation for the relatively high proportion of females affected by autoimmune diseases. This article covers systemic lupus erythematosus, the prototypical autoimmune disease, and antiphospholipid syndrome, which is associated particularly with pregnancy loss.