The length of time that sperm can survive once it leaves the male body depends on several factors, all related to the type of conditions it is exposed to. The primary determining factor for sperm survival is whether it is ejaculated into the female vagina or elsewhere. Sperm that is deposited outside of the body typically dies rapidly, usually within minutes but sometimes after several hours, depending on how quickly it dries up. When sperm is ejaculated into the vagina during intercourse, it can die fairly quickly too, within about half an hour, but if it makes it to the uterus, it may live longer, anywhere from a day to a week. One of the most important factors involved in determining how long it lives at this point is the woman's fertility and the quality of her cervical mucous.
Sperm survival time is usually quite short if it ends up anywhere other than the female vagina. Once it is exposed to air, it begins to dry out rapidly, and once it is dry, it dies. This process often happens within a few minutes of ejaculation, but it can take up to several hours. The length of survival time can be influenced by factors like the amount of moisture on the surface and the temperature. It is also possible for sperm to live for a limited period of time if it is ejaculated into other parts of the body, such as the mouth or stomach during oral sex, but the amount of time will still be minimal since conditions are not ideal.
For sperm to live the longest amount of time possible, it needs to be in the female reproductive tract, and the farther it goes the longer it tends to live. Those sperm that only make it to the vagina usually still die fairly quickly, normally after only 20 to 30 minutes. Sperm survival increases if it manages to travel up to the uterus or beyond to the fallopian tubes, usually taking a day or two. They can survive for as long as four or five days, however, and in extreme cases have been known to live as long as a week.
Where a woman is in her monthly cycle is a major factor in the length of sperm survival. If she is close to ovulation, a woman's body will produce fertile cervical mucous designed to help the sperm swim to the egg. The presence of this type of mucous usually helps sperm live much longer than it could at other times of the month.
