Pregnancy outcome in adult-onset idiopathic inflammatory myopathy

To assess the prevalence of pregnancy in 28 females with dermatomyositis (DM) and polymyositis (PM), assess the outcome in those who became pregnant after the onset of the disease and review the literature of all published cases.

Fifty-four patients with myositis have been under long-term follow-up from 1976-2001 (28 female, nine male).

Twenty-eight female patients were divided into 15 with pure DM/PM (seven PM, eight DM) and 13 with an overlap syndrome. The majority of patients had the onset of the disease after childbearing years (mean age of 32 yr for the overlap group and 41 for the DM/PM group). Only four of our patients (14.3%) have been pregnant after the onset of the disease. One patient had a spontaneous abortion, but was on methotrexate and had active disease; one had a late pregnancy loss, but had active disease; and the other two had uneventful pregnancies during a time when the disease was in remission.

Fetal prognosis in the main reflects the level of maternal disease. The more active the myositis during the pregnancy, the greater the chance of fetal loss.