So my wife and my girlfriend and I have been in a closed committed triad for over 5 years now. My wife has issues with her reproductive system as a result from a miscarriage about 7 years ago. She will have to have a hysterectomy this year. Our girlfriend and I are trying to have a baby together, which my wife is 100% on board with and is excited to finally be a mother. We are going to raise this baby all together.

My question is: I want all three of us to be legal guardians of the baby and have equal and total rights to make decisions regarding the baby's care. How legally can we make this happen? I am sure that other poly parents have gone through this before.