New evidence suggests that those conceived at the start of the year may be at greater risk of being born with learning disabilities.
A study led by scientists in Cambridge and Scotland identified a clear correlation between children being conceived in the often overcast months of January to March and an increased likelihood that they would have a mild, moderate or severe disability.
The research encompassed more than 800,000 school pupils and found that 8.9 per cent of those conceived in the first three months of the year had a learning disability, compared with 7.6 per cent of those conceived in between July and September.
Experts believe that the most likely explanation is a Vitamin D deficiency in mums who become pregnant in the darker months of the year.
January to March is a period when days are short and the comparative lack of sunlight may well affect the quantity of vitamins being produced. This in turn may impact on the development of the baby’s brain.
Professor Gordon Smith, from Cambridge University, said: “Although the current study did not directly measure Vitamin D, it remains perhaps the most plausible explanation for the trend.
“Hence, these findings underline the importance of health professionals recommending Vitamin D, and the importance of women complying with the treatment to optimise their chances of a healthy child.”
Professor Jill Pell, the director of Glasgow’s Institute of Health and Wellbeing, added: “It is important that pregnant women follow the advice to take Vitamin D supplements and also that they start supplements as early in pregnancy as possible – ideally when they are trying to get pregnant.”