Reviving this dead thread to say that as a husband who is going through issues right now with his wife due to the exact same issue as OP, it was encouraging to read so many different viewpoints from mothers and fathers alike.
I can look back and realize that I have made some serious mistakes in my handling of the situation. Right before I wrote this forum post, I texted my wife and apologized for not handling things as well as I should have.
We're on week 10 of her 12 week mat leave (stupid short in my opinion, but you know, MURICA), and we're interviewing nannies today. She's committing to at least going back to work with the understanding that it's easier to go back then quit than it is to quit then go back. If she quits, then it means an instant lifestyle change (no eating out, no cable, cheaper phones, etc.) and dialing back 401k to company match only for me. Even then we're still cash flow negative, so I will probably have to get a second job and we'll explore selling our newly purchased house, among other things.
OP i wish you the best in continuing to figure things out!