Is season of birth associated with multiple sclerosis?

Abstract

A different pattern of MS patients' births is observed in Sicily and in Northern countries.

Multiple sclerosis in South America: month of birth in different latitudes does not seem to interfere with the prevalence or progression of the disease

“…The results from this study show that children born from pregnancies at higher latitudes in South America do not show higher incidence of MS later in life, as is the case with the seasonal pattern observed in the Northern hemisphere [1][2][3][4][5][6][7][8][9] . Therefore, it cannot be affirmed that there is a clear relationship between lower sun exposure in winter pregnancies and the development of MS later in the offspring's life in South America.…”

Seasonal fluctuation of multiple sclerosis births in Sardinia

“…For the primary purpose of comparing our data with those of other published studies, especially in the Mediterranean area [25] and in other very high-risk areas such as Scotland [36], initially four consecutive 3-month seasons (winter, spring, summer and autumn) were considered and defined by taking spring as beginning in April; in addition, and with the aim of further verifying the influence of temperature and climate on MS appearance, the analysis of the birth proportion was performed on a six-month basis by considering the first semester from April until September (temperate half-year composed of spring and summer) and the second from October until March (cold half-year, autumn and winter).…”

“…In theory, identifying seasonal birth clusters of individuals who later in life develop MS may reveal an overlap with specific environmental agents and create new working ideas on maternal-or newborn-acting predisposing factors. Seasonal birth studies exist for many neurological diseases; in some, perinatal external events unlikely represent major factors in determining MS susceptibility [33] whilst in others MS shows a pattern of birth excess in spring or late summer [4,10,25,32,36] and a significant nadir in November [36] which, along with a geographical interaction [32], a strong maternal effect [8,24] and a higher MS rate of dizygotic twins as ■ Abstract Study results from different geographical areas provide some circumstantial evidence that, when compared with the general population, people who later in life develop multiple sclerosis (MS) have a pattern of birth excess numbers in spring and late summer, which may disclose an association with MS-predisposing environmental agents. To identify the presence of season-related cluster of MS birth in Sardinia we have designed a case-control study in the province of Sassari, Northern Sardinia, insular Italy, an area at veryhigh and increasing risk for MS.…”

Timing of Birth and Risk of Multiple Sclerosis in the Scottish Population

“…Previous studies examining month of birth and risk of MS have suggested an increased risk in spring and summer months [7,8,9,10,11,12,13], but have varied in sample size, statistical method, use of controls and findings. As different countries show differing seasons and so environmental changes according to months of the year, it may be assumed that locality should also be considered when examining the relation between timing of birth and risk of MS.…”