Birth timing is tied to both ancient evolutionary roots and modern schedules.
A study out of the UK found that nearly three quarters of births don't happen during the standard 9-5 business hours. According to researchers at City, University of London, 28.5% of babies are born between business hours, while 71.5% of births occur on weekends, holidays or between 5 pm and 8:59 am during the week.
The study is published in the journal PLOS ONE and saw data from 5,093,615 singleton births in England between 2005 to 2014 analyzed. The researchers found most spontaneous births happen in the early morning hours between 1 and 6:59 am, peaking around 4:00am.
The team also looked at the times for "births after induced labors." About a fifth of the babies were born this way, and they were more likely to come into the world around midnight, Tuesdays to Saturdays and on days before a public holiday period.
Scheduled C-sections make up 9.2% of births and were seen to occur mostly on weekdays between 9 and 11:59 am, which totally makes sense. If you're scheduling surgery, you're probably not gonna do it in the middle of the night. Same goes for scheduling C-sections on Christmas Day, although spontaneous births are slower then, too.
"It was not surprising to find that planned caesarean sections are not usually scheduled on holidays, but it is not straightforward to understand why numbers of spontaneous births, without any obstetric intervention, were lower on Christmas Day and Boxing Day than on other days of the year. Selective obstetric intervention in preceding days could be an explanation but more research would be needed to investigate this," says the paper's lead author, Dr. Peter Martin.
Martin says the prevalence of night births may be part of our evolutionary heritage. "Our ancestors lived in groups that were active and dispersed during the day and came together to rest at night. So a night-time labor and birth probably afforded the mother and newborn baby some protection."
These days a night birth won't offer you more protection, but it may offer you less traffic on the way to the hospital, and that's always a plus in the modern age.