The fertilized egg is then inserted into the woman's fallopian tube or uterus. In this case, the woman nourishes the fetus for nine months and gives birth to the baby. The baby contains the genetic material of the woman who donated the egg, and the man who's sperm was used to fertilize the egg. A sperm sample is obtained from the father. Eggs are harvested from the mother.
Fertilization occurs in the laboratory when the sperm are mixed with the eggs.
After 2-3 days, the zygotes are ready to be implanted into the mother's uterus. Some clinics are waiting a full 5-6 days to allow more cell division before implantation. To improve the chances that an embryo will develop into a baby, approximately 3 fertilized eggs are introduced into the uterus at one time. Often this leads to multiple births. A sperm sample is obtained from the father.