The embryo is surrounded with fluid, it's lungs are filled with fluid and it cannot breathe. Why doesn't it suffocate?

The embryo does not suffocate because it receives oxygen and nutrients through the umbilical cord from the mother's bloodstream. The mother's blood carries the necessary oxygen to the placenta, where it diffuses across the placental membrane and into the embryo's bloodstream. This oxygen-rich blood is then circulated throughout the embryo's body, allowing it to survive and grow despite being surrounded by fluid within the womb.