Department of Economics and Business Economics

Birth seasonality and risk of autism spectrum disorder

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  • Brian K Lee, Department of Epidemiology and Biostatistics, A.J. Drexel Autism Institute, Drexel University School of Public Health, Philadelphia, PA, USA.
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  • Raz Gross, Division of Psychiatry, Chaim Sheba Medical Center, Tel Hashomer, Ramat Gan, Israel.
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  • Richard W Francis, Telethon Kids Institute, The University of Western Australia, West Perth, WA, Australia.
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  • Håkan Karlsson, Department of Clinical Neuroscience, Karolinska Institute, and Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden.
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  • Diana E Schendel
  • Andre Sourander, 1] Center for Molecular Recognition, Columbia University College of Physicians and Surgeons, New York, New York, USA. [2] Department of Psychiatry, Columbia University College of Physicians and Surgeons, New York, New York, USA. [3] Division of Molecular Therapeutics, New York State Psychiatric Institute, New York, New York, USA.
  • ,
  • Abraham Reichenberg, Department of Psychiatry and Seaver Autism Center for Research and Treatment, Icahn School of Medicine at Mount Sinai, New York, USA.
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  • Erik T Parner
  • Mady Hornig, Department of Epidemiology and Center for Infection and Immunity, Mailman School of Public Health, Columbia University, New York, NY, USA.
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  • Amit Yaniv, Sackler Faculty of Medicine, Tel Aviv University and the Arrow Project for Junior Investigators, Sheba Medical Center, Tel Hashomer, Tel Aviv, Israel.
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  • Helen Leonard, Telethon Kids Institute, The University of Western Australia, West Perth, WA, Australia.
  • ,
  • Sven Sandin, Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.

Season of birth has been hypothesized to be a risk factor for autism spectrum disorder (ASD). However, the evidence has been mixed and limited due to methodological challenges. We examine ASD birth trends for 5,464,628 births across 5 countries. ASD birth prevalence data were obtained from the International Collaboration for Autism Registry Epidemiology database, including children born in Denmark, Finland, Norway, Sweden, and Western Australia. Empirical mode decomposition and cosinor modeling were used to assess seasonality. We show seasonal variation in ASD births for the countries of Finland and Sweden. There was a modest increase in risk for children born in the fall and a modest decrease in risk for children born in the spring. Solar radiation levels around conception and the postnatal period were inversely correlated with seasonal trends in ASD risk. In the first multinational study of birth seasonality of ASD, there was evidence supporting the presence of seasonal trends in Finland and Sweden. The observations that risk was highest for fall births (i.e., conceived in the winter) and lowest for spring births (i.e., conceived in the summer), and sunlight levels during critical neurodevelopmental periods explained much of the seasonal trends, are consistent with the hypothesis that a seasonally fluctuating risk factor may influence risk of ASD.

Original languageEnglish
JournalEuropean Journal of Epidemiology
Pages (from-to)785-792
Number of pages8
Publication statusPublished - 2019

    Research areas

  • Autism, Empirical mode decomposition, Epidemiology, Seasonality

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