SAT0314 Pregnancy in Adult-Onset Idiopathic Inflammatory Myopathy. Report from A Cohort of Myositis Patients from A Single Center
Authors: I. Pinal-Fernandez, A. Selva-O'Callaghan, A. Fernandez-Codina, X. Martinez-Gomez, J.A. Rodrigo-Pendas, J. Perez-Lopez, M. Vilardell-Tarres
Journal: Annals of the Rheumatic Diseases (2014)

<h3>Background</h3> Idiopathic inflammatory myopathies (IIM) are systemic diseases, characterized by the presence of an inflammatory muscle infiltrate. Although more frequent in women, its relationship with pregnancy has not been extensively studied. <h3>Objectives</h3> Our goal was to analyze the interaction between pregnancy and myositis in a cohort of IIM women from a single center. <h3>Methods</h3> Fifty-one patients from a historical cohort of IIM diagnosed between 1983 and 2013 were interviewed with a specific questionnaire. Comparisons between pregnancies occurring before and after the onset of the disease were performed using generalized mixed-effect models with normal and binomial distributions adjusted for confounding factors and clustering. <h3>Results</h3> One-hundred and two pregnancies from 51 patients (41 dermatomyositis [DM] and 10 polymyositis [PM]) were analyzed. Fourteen (13.7%) pregnancies from 8 patients (5 DM, 3 PM) occurred after disease onset; clinical improvement during gestation was evident in 7 pregnancies (4 patients), 5 of them (from 2 patients) experienced a relapse of IIM symptoms afterwards, while in the rest there was no influence of pregnancy on the disease. No disease flare associated with pregnancy was observed. Two (3.9%) patients (2 DM) were diagnosed within the first 6 months after delivery and none during pregnancy. No evidence was found to support pregnancy as a trigger for myopathy (p=0.10). <h3>Conclusions</h3> Pregnancy does not seem to carry a worse prognosis for the mother nor for the fetus in patients with IIM; on the contrary, near half of the patients in our series improved clinically when they became pregnant, being common a relapse of IIM symptoms afterwards. Pregnancy does not appear to be a trigger for IIM. <h3>References</h3> Vincze M, Danko K. Idiopathic inflammatory myopathies. Best Pract Res Clin Rheumatol. 2012;26:25-45. Rider LG, Miller FW. Deciphering the clinical presentations, pathogenesis, and treatment of the idiopathic inflammatory myopathies. JAMA. 2011;305:183.90. Mastaglia FL, Phillips BA. Idiopathic inflammatory myopathies: epidemiology, classification, and diagnostic criteria. Rheum Dis Clin North Am. 2002;28:723-41. Vargas-Leguás H, Selva-O9Callaghan A, Campins-Martí M, et al. Polymyositis-dermatomyositis: incidence in Spain (1997-2004). Med Clin (Barc). 2007 24;129:721-4. Silva CA, Sultan SM, Isenberg DA. Pregnancy outcome in adult-onset idiopathic inflammatory myopathy. Rheumatology (Oxford) 2003;42:1168-72. King CR, Chow S. Dermatomyositis and pregnancy. Obstet Gynecol 1985;66:589-92. Gutierrez G, Dagnino R, Mintz G. Polymyositis/dermatomyositis and pregnancy. Arthritis Rheum 1984;27:291-4. Kanoh H, Izumi T, Seishima M, Nojiri M, Ichiki Y, Kitajima Y. A case of dermatomyositis that developed after delivery: the involvement of pregnancy in the induction of dermatomyositis. Br J Dermatol 1999;141:897-900. Vancsa A, Ponyi A, Constantin T, Zeher M, Danko K. Pregnancy outcome in idiopathic inflammatory myopathy. Rheumatol Int 2007;27:435-9.12. De Man YA, Dolhain RJ, van de Geijn FE, Willemsen SP, Hazes JM. Disease activity of rheumatoid arthritis during pregnancy: results from a nationwide prospective study. Arthritis Rheum. 2008;59:1241–8. <h3>Acknowledgements</h3> We thank Dr. Pari Basharat and Dr. Arash Lahoutiharahdashti for their critical review of the project. <h3>Disclosure of Interest</h3> None declared <h3>DOI</h3> 10.1136/annrheumdis-2014-eular.1571