There is a paucity of data on maternal and fetal outcomes in patients with inflammatory myositis. The largest series published is from a historical cohort of inflammatory myositis patients in Spain which found that 7/14 pregnancies were associated with symptom improvement during pregnancy, and 7/14 had no change during pregnancy, but 5/14 had a relapse post-partum (Iago et al, 2014).
On Saturday morning at EULAR 2016, researchers from the US presented data on pregnancy in patients with dermatomyositis. Even then, they were only able to collect data on 21 pregnancies in 10 patients from a cohort of 438 DM patients from two centres in US.
Of patients who had symptoms at the time of pregnancy, weakness improved in 81%, cutaneous rash improved in 72% and arthralgias improved in 91%. Of the 21 pregnancies, there was one case of pre-eclampsia, 3 pregnancy losses (2 miscarriages before 10w, 1 TA for ectopic pregnancy) and 3 neonates who needed transfer to the NICU (meconium aspiration, apnea, pre-term birth). There were no cases of ILD or APLA syndrome. There was no data on post-partum myositis flare.
Based on the limited data available, dermatomyositis generally seems to improve in pregnancy with no major maternal or fetal concerns. This was a retrospective observational study, with many potential confounders. I would still counsel patients on potential risk and follow them concurrently with obstetrical medicine specialists.
Dr. Jamal is a Clinical Associate Professor at the University of British Columbia and an active staff physician at Vancouver Coastal Health. Her interests include diagnosis and prognosis of early inflammatory arthritis, and timely assessment and access to care for patients with rheumatoid arthritis.View Full Bio