In the various pantheons immortality and gestation are not mutually exclusive.
Inanna/Istara was born of the earlier Sumerian gods if you go by the Sumerian myths.
Similarly you have the better known (in the USA) Greek and Roman myths where gods are gestated from earlier gods.
I’m aware of the gestated Gods but Venus is often portrayed with a belly button but she came out of an oyster. Adam and Eve often are shown with navels. Angels often are.