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

The fetus can survive with fluid in the lungs because its blood is being oxygenated by the mother’s blood supply via the umbilical cord.

To actually survive via oxygenated fluid in the lungs we would need assistance in getting old fluid out and new fluid in, but we could possibly do it with something like [Perfluorocarbon](https://phys.org/news/2017-03-liquid-closer.html).