As long as the sperm remains alive there is a chance for pregnancy. The lifespan of sperm can be affected by certain factors such as temperature, moisture, lifestyle, and conditions inside the woman's reproductive tract.
Life of Sperm in Different Environments
Once the sperm leave the male body, their days (or minutes!) are definitely numbered.
- Inside a Woman's Cervix or Genital Tract - Sperm can live inside a woman's cervix or upper genital tract for up to 5 days after ejaculation according to the American Pregnancy Association.
- In the Vagina - While the sperm that make it up to the cervix can live up to 5 days, those that stay in the vagina only live a few hours due to the high acidic environment.
- Outside the Body - It depends on the conditions, but it could be as long as 20 minutes.
- On a Dry Surface - According to WebMD, as soon as the semen dries, the sperm are dead.
- In Water - With water, it really depends on the conditions. Too hot and they die immediately. If there is soap or chemicals in the water, they also die immediately. However, if the water is close to body temperature and totally clear they could live a bit longer than in other environments outside of the body. However, it is still minutes or hours vs. days.
Four Factors That Can Impact Sperm Longevity
1. Temperature
According to The Testicular Cancer Research Center, male testicles are anatomically located outside the body to allow sperm to develop at optimal temperatures, which are a few degrees lower than internal body temperature. According to WebMD, men can preserve the lifespan of their sperm by avoiding overheating the testicular area. Activities that could lead to overheating include the use of saunas and hot tubs and wearing tighter clothing or briefs that trap heat.
Sperm longevity can also be affected by fever in men. A study published in the October 18, 2003 edition of Human Reproduction reported that high fever in men negatively impacts the production of sperm. Fever can lead to morphologic changes in sperm which decrease production and longevity. These effects can last for several weeks after the fever and may be dependent on how long the fever existed.
2. Moisture
Sperm do not live long without moisture. Sperm account for between two and five percent of the composition of semen. The semen provides a moist, nutrient rich environment for sperm according to News Medical. Once outside the body, the sperm will only live until the semen dries.
Web MD states that semen can live longer inside water such as a bathtub or pool than on a dry surface, but the likelihood of the sperm finding its way into a woman's body from a pool of water is slim.
3. Lifestyle
Lifestyle choices in men can also have an effect on sperm's longevity. According to an article published in the December, 2010 issue of Human Fertility, several factors including cigarette smoke, air pollution, and sexually transmitted disease all have a potentially negative impact on sperm genetics and can lead to a shorter lifespan in sperm.
Illicit drug use, alcohol use, the use of anabolic steroids, and being overweight can have a detrimental effect on sperm, inhibiting sperm production and shortening sperm lifespan.
4. Woman's Reproductive Tract
A woman's pH has an effect on the longevity of sperm. Certain times of the month, the pH in the female reproductive tract is hostile to sperm and creates a toxic environment. During ovulation, the pH of the vagina increases, becoming more alkaline and less toxic to sperm.
According to The American Pregnancy Association, a spike in luteinizing hormone is what triggers ovulation. The increase in luteinizing hormone leads to an increase in the PH of the cervical mucosa. This seems to be nature's way of increasing a woman's chances of becoming pregnant.
Timing Considerations
The timing of intercourse is important for achieving (or preventing) pregnancy. Intercourse must occur around the time of ovulation for pregnancy, so timing intercourse around ovulation or avoiding intercourse during this time will affect a woman's likelihood of becoming pregnant.
A woman's body temperature will typically rise slightly a day or two after ovulation. When this happens; the window of opportunity to become pregnant during that cycle closes until the next cycle. Knowing that sperm can live up to seven days inside a woman's body can allow a couple to plan accordingly.
