Sperm can survive for several days in the female reproductive tract and remain capable of fertilization for 2-3 days, while the egg only survives for about 24 hours after discharge and then degenerates. This requires the sperm to wait for the egg to increase the chances of an encounter. Therefore, if the time of ovulation cannot be accurately determined, it is easier to conceive 1 to 2 days earlier than later on the wrong day. How long does it take for the sperm and egg to unite? When a couple is preparing for conception during intercourse, the man discharges about 200 to 400 million sperm each time, most of which are discharged from the vagina with the semen, while a small percentage of sperm rely on the tail swing to advance, successively passing through the cervical canal, uterine cavity and finally reaching the terminal point – the abdomen of the fallopian tube, where they wait to unite with the egg. It takes 1 to 1.5 hours to expel the sperm and go to the fallopian tube to wait for the egg to unite. During intercourse, a man expels about 200 to 400 million sperm each time, however, most of the sperm are expelled from the vagina with the semen. Because the cervical canal mucus is alkaline, which is conducive to sperm activity, a small portion of sperm rely on the tail swing forward, and soon swim to the cervical canal, sperm release proteolytic enzymes to dissolve the cervical mucus; the contraction of the uterus caused by sexual intercourse and the peristaltic movement of the fallopian tube accelerates the movement of sperm. The sperm swim to the abdomen of the fallopian tube, where they wait to join the egg. The fastest time for sperm to reach the fallopian tube from the vagina is just a few minutes, the latest 4 to 6 hours, and usually 1 to 1.5 hours.