BACKGROUND Currently, there are few studies that describe pregnancy in dermatomyositis/polymyositis patients, and they are largely limited to case reports or studies with few samples. OBJECTIVE Therefore, we describe the pregnancy in a large sample of patients with dermatomyositis/polymyositis and to analyze the outcomes in those who became pregnant during or after disease onset. METHODS The present single-center study analyzed 98 female patients with idiopathic inflammatory myopathies (60 dermatomyositis and 38 polymyositis patients). They were interviewed to obtain obstetric antecedent and demographic data from June 2011 to June 2012. RESULTS Seventy-eight (79.6%) of the 98 patients had obstetric histories. Six polymyositis and 9 dermatomyositis patients became pregnant after disease onset. The pregnancy outcomes in these cases were good, except in the following cases: 1 disease reactivation, 1 intrauterine growth retardation, 1 diabetes mellitus, 1 hypertension, 1 hypothyroidism, and 2 fetal losses (same patient). Moreover, 2 patients developed dermatomyositis during pregnancy and 4 (2 polymyositis and 2 dermatomyositis) during the postpartum period with good control after glucocorticoid and immunosuppressant therapy. CONCLUSIONS The adverse obstetric events were related to clinical intercurrences and the pregnancy does not seem to carry a worse prognosis specifically in disease (for example: disease relapsing). Moreover, dermatomyositis or polymyositis onset during pregnancy or the postpartum period had good outcome after drug therapy.