Clinical markers of asthma and IgE assessed in parents before conception predict asthma and hayfever in the offspring.

"Conflict of interest The authors declare no conflict of interest."

"Sources of funding This work is part of the Ageing Lungs in European Cohorts (ALEC) Study (www.alecstudy.org), which has received funding from the European Union's Horizon 2020 Research and Innovation Program under grant agreement No. 633212. The following grants helped to fund the local studies: Financial support for ECRHS I: Australia: Asthma Foundation of Victoria, Allen and Hanbury's, Belgium: Belgian Science Policy Office, National Fund for Scientific Research, Denmark: The Danish Lung Association, Estonia: Estonian Science Foundation, grant no 1088, France: Ministère de la Santé, Glaxo France, Insitut Pneumologique d'Aquitaine, Contrat de Plan Etat‐Région Languedoc‐Rousillon, CNMATS, CNMRT (90MR/10, 91AF/6), Ministre delegué de la santé, RNSP, France; GSF, Germany: Bundesminister für Forschung und Technologie, Greece: The Greek Secretary General of Research and Technology, Fisons, Astra and Boehringer‐Ingelheim; India: Bombay Hospital Trust, Italy: Ministero dell'Università e della Ricerca Scientifica e Tecnologica, CNR, Regione Veneto grant RSF n. 381/05.93, New Zealand: Asthma Foundation of New Zealand, Lotteries Grant Board, Health Research Council of New Zealand, Norway: Norwegian Research Council project no. 101422/310; Portugal: Glaxo Farmacêutica Lda, Sandoz Portugesa, Spain: Fondo de Investigación Sanitaria (#91/0016‐060‐05/E, 92/0319 and #93/0393), Hospital General de Albacete, Hospital General Juan Ramón Jiménez, Dirección Regional de Salud Pública (Consejería de Sanidad del Principado de Asturias), CIRIT (1997 SGR 00079) and Servicio Andaluz de Salud; Sweden: The Swedish Medical Research Council, the Swedish Heart Lung Foundation, the Swedish Association against Asthma and Allergy; Switzerland: Swiss National Science Foundation grant 4026‐28099; UK: National Asthma Campaign, British Lung Foundation, Department of Health, South Thames Regional Health Authority, USA: United States Department of Health, Education and Welfare Public Health Service (grant #2 S07 RR05521‐28). Financial Support for ECHRS III Australia: National Health & Medical Research Council, Belgium: Antwerp South, Antwerp City: Research Foundation Flanders (FWO), grant code G.0.410.08.N.10 (both sites), Denmark: The Faculty of Health, Aarhus University No. 240008, The Wood Dust Foundation No. 444508795, Estonia: Tartu‐ SF0180060s09 from the Estonian Ministry of Education. France: (All) Ministère de la Santé. Programme Hospitalier de Recherche Clinique (PHRC) national 2010 Bordeaux: INSERM U897 Université Bordeaux segalen Grenoble: Comitee Scientifique AGIRadom 2011. Paris: Agence Nationale de la Santé, Région Ile de France, domaine d'intérêt majeur (DIM) Germany : Erfurt: German Research Foundation HE 3294/10‐1 Hamburg: German Research Foundation MA 711/6‐1, NO 262/7‐1 Iceland: Reykjavik, The Landspitali University Hospital Research Fund, University of Iceland Research Fund, ResMed Foundation, California, USA, Orkuveita Reykjavikur (Geothermal plant), Vegagerðin (The Icelandic Road Administration (ICERA)). Italy: All Italian centres were funded by the Italian Ministry of Health, Chiesi Farmaceutici SpA, and in addition, Verona was funded by Cariverona Foundation, Education Ministry (MIUR). Norway: Norwegian Research Council grant no 214123, Western Norway Regional Health Authorities grant no 911631, Bergen Medical Research Foundation. Spain: Fondo de Investigación Sanitaria (PS09/02457, PS09/00716 09/01511, PS09/02185, PS09/03190), Servicio Andaluz de Salud, Sociedad Española de Neumología y Cirurgía Torácica (SEPAR 1001/2010); Barcelona: Fondo de Investigación Sanitaria (FIS PS09/00716) Galdakao: Fondo de Investigación Sanitaria (FIS 09/01511) Huelva: Fondo de Investigación Sanitaria (FIS PS09/02185) and Servicio Andaluz de Salud Oviedo: Fondo de Investigación Sanitaria (FIS PS09/03190) Sweden: All centres were funded by The Swedish Heart and Lung Foundation, The Swedish Asthma and Allergy Association, The Swedish Association against Lung and Heart Disease. Swedish Research Council for health, working life and welfare (FORTE) Göteborg : Also received further funding from the Swedish Council for Working Life and Social Research. Umea also received funding from Vasterbotten Country Council ALF grant. Switzerland: The Swiss National Science Foundation (grants no 33CSCO‐134276/1, 33CSCO‐108796, 3247BO‐104283, 3247BO‐104288, 3247BO‐104284, 3247‐065896, 3100‐059302, 3200‐052720, 3200‐042532, 4026‐028099) The Federal Office for Forest, Environment and Landscape, The Federal Office of Public Health, The Federal Office of Roads and Transport, the Canton's Government of Aargan, Basel‐Stadt, Basel‐Land, Geneva, Luzern, Ticino, Valais and Zürich, the Swiss Lung League, the Canton's Lung League of Basel Stadt/Basel, Landschaft, Geneva, Ticino, Valais and Zurich, SUVA, Freiwillige Akademische Gesellschaft, UBS Wealth Foundation, Talecris Biotherapeutics GmbH, Abbott Diagnostics, European Commission 018996 (GABRIEL), Wellcome Trust WT 084703MA, UK: Medical Research Council (Grant Number 92091), Support also provided by the National Institute for Health Research through the Primary Care Research Network. The coordination of the ECRHS III was funded through the Medical Research Council (Grant Number 92091)."