Sperms are deposited at the posterior vault of vagina from where that start their journey towards fallopian tube. On the way, they have to cross cervix and uterus before reaching near to egg. Al sperms can not reach to fallopian tube. A good quality of ejaculate contains 25-30% fast moving sperms. These fast moving sperms can reach near egg within 15-20 minutes. If ejaculate contains less percentage of fast moving sperms then more time is needed that can be up to few hours. Once sperms reach near egg, they start to secrete enzyme that dissolve the egg shell and then one sperm can unite with egg to cause pregnancy.
