A few years back we had a relative of my Norwegian grandfather contact us with a family history he had done.
What surprised me was the number of weddings and baby baptisms (baby from the couple being married) that occurred simultaneously.
And this was the 1850’s.
My father said it was because the norwegians were fishermen who at sea for long periods of time working. I replied that it looks like they were pretty busy on the land too ;-)
In Iceland it’s traditional that you don’t marry until the woman proves she can give you children.