But, he said, for unknown reasons the cloned embryos died when they grew to 16 cells.

Dinosaurs didn't turn their eggs like birds, for the embryo inside would have died.

Predators are known to eat the eggs and the embryos inside can also die of cold in the mother's absence.

In those pregnancies, placentas form, but the embryos die.

But the embryos died before they had even eight cells, and most died long before that.

Six lasted for five days, but, as in the other experiments, the embryos died before forming stem cells.

But the embryos quickly died, and some experts outside the company called the experiment a failure.

All the embryos died, but the debate over human cloning is once again alive.

A spontaneous abortion is when the fetus or embryo dies and comes out on its own.