Prior to fertilization, sperm undergo a process of capacitation in response to conditions in the female reproductive tract, which include increases in motility and destabilization of the cell membrane...Prior to fertilization, sperm undergo a process of capacitation in response to conditions in the female reproductive tract, which include increases in motility and destabilization of the cell membrane that allows the head of the sperm to penetrate the egg. If pregnancy is considered to begin at the point of implantation, the process leading to pregnancy occurs earlier as the result of the female gamete, or oocyte, merging with the male gamete, or spermatozoon.
