Winter babies could be more at risk of having a stroke in later life, a US study implies.
This is due to their mothers’ first trimester being during summer, when air pollution is typically more severe. Air pollution exposure has previously been linked to the development of an irregular heartbeat, which can cut off the brain’s blood supply.
As The Daily Mail reports, autumn birthdays may prevent people developing diabetes, the research adds, as their mother’s third trimester would have been during summer when vitamin D levels are high.
As vitamin D strengthens the immune system, exposure to the so-called sunshine supplement during the final stages of pregnancy may prevent autoimmune conditions, such as diabetes.
Study author Dr Mary Regina Boland said: ‘Overall, our findings demonstrate the importance of environmental factors, including socio-environmental factors such as relative age, on the development of childhood diseases.’
How the research was carried out
Researchers from the University of Pennsylvania analyzed the electronic health records of 10.5 million people in the US, South Korea and Taiwan.
They correlated any disease with the study’s participant’s birth month.
Winter babies are at risk of stroke, but autumn birthdays prevent diabetes.
Results reveal babies born between December and March are more at risk of having an irregular heartbeat, which is a major cause of stroke.
This is due to the pregnancy’s first trimester being in the summer, which is when air pollution in cities is typically more severe due to vehicle emissions reacting with sunlight to create smog.
The findings also reveal babies born in autumn are less at risk of developing type 2 diabetes.
This is due to their mothers having more vitamin D exposure in their third trimester as it occurred during the summer months.
Diabetes, which is an autoimmune condition, is thought to be prevented by the so-called sunshine supplement as it strengthens the immune system.
Study author Dr Boland said: ‘All of our major findings linking birth seasonal patterns with variance in environmental exposures fit into known mechanistic pathways.
‘Overall, our findings demonstrate the importance of environmental factors, including socio-environmental factors such as relative age, on the development of childhood diseases.’
The findings were published in the Journal of the American Medical Informatics Association.
