Dermatomyositis.

Pregnancy in DM/PM is infrequent probably because of the late age of onset of the disease. When pregnancy occurs in patients with long-standing remissions of childhood onset DM/PM the risk of exacerbation is 40 per cent and the prognosis for the fetus is reasonably good. If pregnancy starts in patients already diagnosed and under steroid treatment of DM/PM, the frequency of exacerbations is low (16 per cent) and the outcome of pregnancy is not as good, with only 50 per cent at-term babies and 37.5 per cent fetal loss. When DM/PM has its onset during pregnancy the fetal mortality reaches 62 per cent. No maternal deaths have been reported. The response to steroid therapy for active DM/PM during pregnancy seems to be good with two patients recovering their muscle strength very rapidly after delivery. There are no placental abnormalities that could explain the increased fetal loss. The newborns have no stigmata of the maternal disease. Pregnancy in DM/PM should be considered a high-risk pregnancy and managed accordingly; adequate prednisone therapy for the maternal disease, frequent monitoring of the growth and development of the fetus, careful search for signs of fetal distress and interruption of pregnancy as needed with the care of a neonatologist at the time of delivery. The mechanisms of the reciprocal interaction between DM/PM and pregnancy are unknown.