Out-of-hours births 'are riskier'

Babies born at night or at the weekend are at a greater risk of dying than those born within normal working hours, a study suggests.

The analysis of more than one million births in Scotland over two decades found the risk of death for babies born out of hours, while small, was a third higher than for those born in the day.
http://www.bbc.co.uk/news/health-10631092

I find it very hard to believe the findings of these surveys and studies. I can't understand why there should be any difference between babies born in the day and babies born at night or weekend. I also question the amount of money spent on studies like this when they don't appear to make any differences. Surely the money could be better spent in our health boards.