Pregnancy Complicated by Dermatomyositis

Pregnancy complicated by DM is rare. There are a limited number of case reports on the debut of DM during pregnancy. It is not clear whether the association of pregnancy with DM is actually low, because the rarity of pregnancy-associated DM may reflect a low incidence of DM in young adult women. There are no available epidemiological data on pregnancy and DM/PM. The association of PM/DM and pregnancy is very rare, and this has been attributed to the low percentage (14%) of cases in which the disease begins during the reproductive period of a woman's life [1]; it is also probable that family planning policy after the clinical manifestation of the disease lowers the association of PM/DM and pregnancy [2]. In one hospital-based myositis study of 22 women, myositis developed during the childbearing years in eight of them (36%) and three (13.6%) presented with PM within 3 months of delivery [3]. A relationship between pregnancy and DM has rarely been documented, and most cases have been reported from the viewpoint of the management of high-risk pregnancy [4–6].

There are at least two types of pregnancy-related DM. In the first type, the disease activity is provoked during pregnancy and tends to improve after delivery, while in the other type the onset is in the postpartum period [6]. The onset of DM has been reported during all three trimesters of pregnancy. The initial symptoms are usually nonspecific and include slight fatigue, which is common during pregnancy, and periungal erythema on the backs of the fingers, which could easily be overlooked by other than dermatologists. The uterus is unaffected by the myositic progression of the disease, athough England et al. [7] described a patient with a hypotonic uterus. In most cases the myositis of the mother improved after delivery, and occasionally remission was observed immediately postpartum [5, 6]. In other cases the myositis in the mother worsened after delivery [6, 8]. In order to find common features of DM/PM with pregnancy-associated onset Kanoh et al. [6] have summarized 15 case reports. In 12 of the 15 patients, the disease developed during pregnancy. In the majority of those cases the disease was active and resistant to steroid therapy during pregnancy but improved after delivery [6]. Apparent high risk for both premature delivery and fetal mortality in these cases is also shown. If the onset was in the first trimester, fetal mortality was very high (83%), and even with onset in the second or third trimester, the risk for premature delivery remained high, although all infants were alive. In contrast, postpartum onset of DM is extremely rare, and only three cases have been reported [6].