Nina Brochmann, Ellen Steken Dal. VIva la vagina (№ 382835)

The mother's body is able to assess the quality of the embryo when the fertilized egg attaches to the uterine wall. As you will read further, not all the fertilized eggs turn into babies. Abortions embryos at a very early stage due to the fact that they have genetic abnormalities. It would be unwise to waste energy on non-viable offspring. If the mother's body will be able to understand that the embryo is defective, it will save valuable resources, time getting rid of "ballast".