How does an embryo get oxygen and nutrients from its mom?

Answer 1

A mammalian embryo gets oxygen and nutrients from it mother by means of the umbilical cord which extends the embryonic blood supply into the placenta embedded in the mothers womb. The blood supply in the placenta is close to that of the mother and oxygen and nutrients diffuse across from the mother to the baby.

With egg laying animals the nutrients are supply to the embryo as the yolk part of the egg and oxygen is supplied by diffusion through the permeable shell and shell membrane