David K. Gardner • Denny Sakkas
Emre Seli • Dagan Wells
Editors
2013
Assessment and Diagnosis
Human reproduction is very inef fi cient. Considering the overpopulation of many regions of our world, how can this be true? The simplistic answer is that the reproductive cycle operates about 13 times each year. In normal reproduction, although greatly in fl uenced by age, on average only about one in fi ve unions of sperm and egg result in a normal neonate. There is abundant evidence that about two-thirds of these failures are due to chromosomal aneuploidy.