http://www.businessinsider.com/scien...d-for-everyone
http://www.nytimes.com/2015/02/01/up...eave.html?_r=0
http://www.cnn.com/2015/10/29/health...dren-research/
http://www.pbs.org/newshour/making-s...l-leave-helps/
US' native fertility rate is in the realm of 1.88 per woman, replacement is about 2.1.America isn't dependent on immigration to keep a steady population. And unabashed immigration is a large factor in our economy doing so poorly.
So, no. The US like the vast majority of developed countries requires immigration to sustain growth.