More and more, now that the taboo is breaking down to some degree. This has been the subject of some recent press reporting.[0][1]
That said, it is disturbing to me, at least, how people’s having children might rewire their brains. They might like their new role only because of certain changes in brain chemistry that result from parenthood. Their fondness for being parents is therefore something forced on them in a way, it is not a matter of actual choice.
[0] https://www.theguardian.com/lifeandstyle/2016/may/09/love-re... [1] https://www.theguardian.com/lifeandstyle/2017/feb/11/breakin...