Will the infant be a lady or Boy ?Improve likelihood of a child Just before conception, the unfertilized egg holds an X chromosome although the semen can hold either an X or a Y chromosome. The sex associated with the infant boils down to 1 easy occasion: A girl will be conceived if the sperm carrying an X chromosome fertilizes the egg. In the event that semen holding a Y chromosome fertilizes the egg, a child will likely be conceived.