We’re not very accommodating of parenthood here in the US. Medical costs aside, my employer only offers two weeks of paid parental leave after having a child.
Ironically, Dutch paternity leave is only 2 days (paid), but you’re legally allowed to take something like 26 weeks unpaid in the first few years as parental leave. (Vs e.g. Sweden with 6-9 months). The law is changing to a few weeks next year I believe.
I think it differs by employer. Mine gives extra days paid leave for parents as they consider the 2 days too short (but this is uncommon) and proactively asked if I was considering 90% or 80% for the coming year, and shared how others have done this.
At my wife’s workplace there are many people with children, and the large majority works either 3 or 4 days per week.