ORIGINAL ARTICLE Epidemiology of Allergic Disease Enterovirus infection during pregnancy is inversely associated with atopic disease in the offspring Laura Korhonen 1,2,3 | Tapio Seiskari 4 | Jussi Lehtonen 1 | Leena Puustinen 1 | Heljä-Marja Surcel 5,6 | Anna-Maija Haapala 4 | Onni Niemelä 7 | Suvi M. Virtanen 8,9,10,11 | Hanna Honkanen 1 | Mira Karjalainen 12 | Jorma Ilonen 13,14 | Riitta Veijola 12 | Mikael Knip 15,16,17,18 | Maria Lönnrot 1,2,3 | Heikki Hyöty 1,4 1 Department of Virology, Faculty of Medicine and Life Sciences, University of Tampere, Tampere, Finland 2 Department of Dermatology, Tampere University Hospital, Tampere, Finland 3 Allergy Centre, Tampere University Hospital, Tampere, Finland 4 Department of Clinical Microbiology, Fimlab Laboratories Ltd, Tampere, Finland 5 National Institute for Health and Welfare, Oulu, Finland 6 Biobank Borealis of Northern Finland, Oulu University Hospital, Oulu, Finland 7 Department of Laboratory Medicine and Medical Research Unit, Seinäjoki Central Hospital and University of Tampere, Seinäjoki, Finland 8 Unit of Nutrition, National Institute for Health and Welfare, Helsinki, Finland 9 Faculty of Social Sciences/Health Sciences, University of Tampere, Tampere, Finland 10 Center for Child Health Research, University of Tampere, Tampere University Hospital, Tampere, Finland 11 The Science Center, Pirkanmaa Hospital District, Tampere, Finland 12 Department of Pediatrics, PEDEGO Research Unit, Medical Research Center, Oulu University Hospital and University of Oulu, Oulu, Finland 13 Immunogenetics Laboratory, Institute of Biomedicine, University of Turku, Turku, Finland 14 Clinical Microbiology, Turku University Hospital, Turku, Finland 15 Children's Hospital, University of Helsinki and Helsinki University Hospital, Helsinki, Finland 16 Research Programs Unit, Diabetes and Obesity, University of Helsinki, Helsinki, Finland 17 Folkhälsan Research Center, Helsinki, Finland 18 Department of Pediatrics, Tampere University Hospital, Tampere, Finland Correspondence Laura Korhonen, Department of Dermatology, Tampere University Hospital, Tampere, Finland. Email: laura.korhonen@sll.fimnet.fi Funding information This work was funded by the European Comission Persistent Virus Infection in Diabetes Network [PEVNET] Frame Programme 7Contract No. 261441, Tampere Tuberculosis Foundation, Sigrid Juselius Foundation, Academy of Finland [PREVALLER consortium, Grant 129448‐ 2008; Research Grant 132362‐2009; Centre of Excellence in Molecular Systems Immunology and Physiology, Grant 250114 2012–2017], The National Technology Agency in Finland (TEKES), Päivikki and Summary Background: Prenatal environment has been shown to influence child's risk of ato- pic diseases. Laboratory‐confirmed data about the role of maternal infections during pregnancy is scarce. Objective: The aim of this study was to determine the associations between sero- logically confirmed maternal infections during pregnancy and atopic disease in the offspring. Methods: This was a nested case‐control study within a prospective birth cohort study. Altogether 202 atopic case children and 333 matched non‐atopic control chil- dren were included. Atopic outcome was defined as having an atopic disease and IgE sensitization by the age of 5 years. We analysed serologically acute enterovirus (EV), influenza virus A (IAV) and Mycoplasma pneumoniae (M. pneumoniae) infections Received: 24 January 2018 | Revised: 12 August 2018 | Accepted: 1 September 2018 DOI: 10.1111/cea.13280 1698 | © 2018 John Wiley & Sons Ltd wileyonlinelibrary.com/journal/cea Clin Exp Allergy. 2018;48:1698–1704.