Lower Maternal UV Exposure May Raise Offspring's MS Risk
Ambient exposure to ultraviolet radiation in first trimester, region of birth linked to risk
FRIDAY, April 30 (HealthDay News) -- Both region of birth and low first-trimester maternal exposure to ultraviolet radiation are linked to an increased risk of subsequent multiple sclerosis (MS) in offspring in Australia, according to research published online April 29 in BMJ.
Judith A. Staples, of the Australian National University in Canberra, and colleagues studied birth month and year (1920 to 1950), region of birth, and sex for all patients surveyed in several regions of Australia in 1981. They generated a variable for ambient ultraviolet radiation exposure "at birth" for 1,524 patients with MS born in Australia between 1920 and 1950.
The researchers found that the risk of MS was increased for those born in the Australian summer months of November and December compared to those born in May and June (adjusted incidence rate ratio, 1.32). Region of birth was also associated with risk. There was an inverse association between the mother's ambient ultraviolet radiation exposure in the first trimester and risk of MS in the offspring after adjustment for region of birth. The risk of MS was 67 percent greater for the lowest level of maternal first trimester ultraviolet light exposure, compared to the highest. After adjustment for this maternal exposure, there was no residual association between birth month and MS.
"The findings here provide the first population based evidence beyond month of birth patterns to indicate that vitamin D supplementation for the prevention of MS might also need to be considered during in utero development," the authors write.