Researchers at the Karolinska Institutet in Sweden have now made a breakthrough in understanding how fertilization ... multiple sperm cells fuse with a single egg and can make it unviable.

Two weeks after a human egg is fertilized, primordial germ cells (PGCs), which develop into sperm and eggs, are formed. In six to 10 weeks after fertilization, PGCs differentiate into pro ...

Every now and then, a fertilized human egg starts to develop into a fetus outside the uterus, within the mother's abdominal cavity. Known as an abdominal pregnancy, this is very dangerous ...

The fusion of sperm and egg gametes during human fertilization establishes a diploid zygote and initiates a series of cell divisions that result in a multicellular embryo. The blastocyst stage is ...

Though the genetic code of a human being is contained within 46 chromosomes, only half of this number exists within the cell of a sperm or egg. If the cells didn't have half, a fertilized egg ...

Infertility is a major global challenge associated with physiological and psychological impact. Genetic mutations that affect ...

It met this challenge by devising (again, speaking from a human perspective) a system by which parent cells incorporate ... When an egg and sperm unite to make a fertilized egg, the chromosomes ...

One extremely rare protection strategy arises in response to a very unusual and also unfortunate set of circumstances. Every now and then, a fertilized human egg starts to develop into a fetus outside ...

A number of other challenges remain for the test. The genetic screening technology removes from the fertilized eggs cells that would otherwise become placenta. The possibility cannot be ruled out ...