For a pregnancy to occur, an egg must be released from one of a woman’s ovaries, move into the Fallopian tube, and down that towards the uterus. At the same time, sperm released during ejaculation by a man must move from the vagina through the cervix and uterus and into a fallopian tube, which contains a recently released egg. One sperm and an egg must then fuse together, start dividing into a multi celled structure, travel down the Fallopian tube and implant into the lining of the uterus, where it can obtain nutrition from the mother and continue to grow.
Getting Pregnant – How Pregnancy Starts
(Last modified: 10th Oct 2014)