Full transcript. The sperm race begins Ejaculation The race resumes A man's penis releases around 20 million sperm into the woman's vagina, where they then begin their journey.Around 2,000 sperm then travel up to the top of the vagina and through the cervix.aiting for the egg When the sperm are awakened they travel to egg and the race resumes. Time to be born The mother's Muscles contract to push the baby out. The amnion sack breaks ('water' breaks). The head moves into the entrance of the vagina.