I would definitely make sure your support network also plans on helping you as much as you expect them too. Compare the social support system you’d have in AUS/NZ with the social support system you’ll have in your state in the US. Compare the parental leaves. Compare the commutes. Don’t just look at how it will be when your kid is an infant and it’s tough - compare it long term as well.

Personally, very very little would make me consider moving back to the US to start a family.