Would it be practical to keep the womb alive via a heart/lung machine and blood transfusions? Just remove human beings from the process altogether?
Given that we're getting better at growing body parts from stem cells, you could easily imagine in the nearish future being able to gestate an embryo in a womb grown from an individuals own stem cells and enough attached organs to provide the full environment.
Whales have the right body temperature. There is enough room to do dozens of babies at once.
Cows are close enough. A cow can probably handle a half dozen babies.
https://en.wikipedia.org/wiki/Interspecific_pregnancy#Causes...
We can suppress the immune response, one way or another. If the animal is unable to clear the placenta after the birth, we lose the animal, but we still get a baby.
I bet there’s a market for a sci fi book in which a generation of test tube babies simultaneously develop a fetishization for some low quality diet supplement that happens to be present in the natal feeding fluid they were exposed to for their formative years.