Eli5 If a fetus can breathe fluid can or lungs be filled with a fluid that provides enough oxygen to “breathe”

Question

Title

In: Biology

Answer 1

A fetus can’t breathe fluid. The umbilical cord provides the oxygen they need (through oxygenated blood).

That said, I’m not familiar enough with how the transfer of oxygen into the lungs works to say whether or not it would be possible to create a liquid that the lungs can get oxygen out of.