After the sperm in the fallopian tube of the mother fertilizes the egg the fertilized egg gives rise to three basic kinds of cells:

Primitive germ cells

Normal body or somatic cells

Trophoblast cells

By the third day the fertilized egg has fallen into the uterus. During those three days and for many days thereafter, the trophoblast cells (cancer cells) are growing very rapidly and surround the other two types of cells (primitive germ cells, and normal body or somatic cells).

The new baby will fall out of the uterus unless something happens fast, and happen it does. The trophoblast cells metastasize (as cancer does) to the wall of the uterus. Now the baby cannot fall out of the mother’s uterus, but needs nourishment. The trophoblast cells (cancer cells) continue to grow rapidly and form the placenta. Now with a good food supply and no danger of falling out of the mother, the baby (embryo) can continue to grow, safe and sound, until birth.

The placental trophoblast tissue (cancer mass) continues to grow until about the seventh week when the baby’s pancreas develops.

The baby’s pancreatic enzyme production along with the mother’s pancreatic enzyme production stops the growth of the placental trophoblastic tissue.

As the new embryo (baby) is being formed from the normal body or somatic cells, the primitive germ cells (pre-placenta cells) are multiplying. In a few days, when the embryo (baby) develops to the proper stage, the primitive germ cells stop multiplying and begin to migrate to the gonads (ovaries or testes).