When you're not dating someone seriously, you're asked if there is anyone special in the picture.
When you are dating someone for a while, you're asked if this is the one.
When you've made that official, you're asked if there is any news, children-wise.
There's a lot of societal pressure from family and friends to have kids or risk being perceived as a disappointment or failure.
If none of that was there, fewer people might have kids.