J Salzer1, A Svenningsson, P Sundström. 1. Department of Neurology, Umeå University Hospital, Umeå, Sweden. jonatan.salzer@neuro.umu.se
Abstract
OBJECTIVE: To estimate the risk of multiple sclerosis (MS) by month of birth in Sweden. MATERIALS AND METHODS: Cases (n = 9361) were obtained from the Swedish MS Registry. All births in Sweden 1900-2007 served as controls (n = 12,116,853). The risk of MS was analyzed for each month of birth separately compared with birth during the other 11 months. RESULTS: More (11%) cases with MS than expected were born in June. Fewer (8% and 10%) cases with MS than expected were born in December and January (non-significant after correction for multiple analyses). More (5%) cases with MS than expected were born in February-July as compared with August-January. CONCLUSIONS: This study supports previous results suggesting an association between the risk of MS and the season of birth. Decreased exposure to sun in the winter leading to low vitamin D levels during pregnancy is a possible explanation that needs further research.
OBJECTIVE: To estimate the risk of multiple sclerosis (MS) by month of birth in Sweden. MATERIALS AND METHODS: Cases (n = 9361) were obtained from the Swedish MS Registry. All births in Sweden 1900-2007 served as controls (n = 12,116,853). The risk of MS was analyzed for each month of birth separately compared with birth during the other 11 months. RESULTS: More (11%) cases with MS than expected were born in June. Fewer (8% and 10%) cases with MS than expected were born in December and January (non-significant after correction for multiple analyses). More (5%) cases with MS than expected were born in February-July as compared with August-January. CONCLUSIONS: This study supports previous results suggesting an association between the risk of MS and the season of birth. Decreased exposure to sun in the winter leading to low vitamin D levels during pregnancy is a possible explanation that needs further research.
Authors: Barnaby Fiddes; James Wason; Anu Kemppinen; Maria Ban; Alastair Compston; Stephen Sawcer Journal: Ann Neurol Date: 2013-07-02 Impact factor: 10.422
Authors: Diana Andrea Fernandes de Abreu; Véréna Landel; Adrian G Barnett; John McGrath; Darryl Eyles; Francois Feron Journal: Int J Mol Sci Date: 2012-08-30 Impact factor: 6.208