TUESDAY, 20 OCTOBER 2015
The study, lead by Dr. Perry from the Medical Research Council (MRC) Epidemiology Unit, used a long-term data-set from the UK Biobank Study, a major national health resource, to analyse how different traits relate to the month when a baby is born. Using information from 500,000 people the group found that individuals born between June and August had a larger weight at birth and developed into taller adults than those born in other months.Babies born in December showed the exact opposite pattern. Furthermore, they also found a relationship between the birth month and the likelihood of studying beyond the age of 16. This effect was particularly strong between August and September: Babies born in the later were much more likely to study beyond the age 16 than babies born in the former. These correlations (non-causal relationships) remained significant even when statistically controlling for important factors, like socio-economic rank, smoking and educational attainment of the parents.
What could be driving this effect remains unknown, but one possibility is that it depends on how much vitamin D the mother gets during pregnancy. Mothers giving birth in the summer receive more sunlight (and hence a higher vitamin D exposure) in the second trimester of their pregnancies, at least in the UK, where the data came from. However, this idea remains to be properly tested by future work.
DOI: 10.1016/j.heliyon.2015.e00031
Written by Ornela De Gasperin.
