Exocytosis may cause sperm to remain outside the body. So, how long do sperm survive outside the body? Please refer to the detailed science popularization in the encyclopedia.
Under normal circumstances, within one hour of ejaculation, more than 70% of sperm should be alive. If the number of dead sperm exceeds 40%, it will affect conception. Sperm survival time should maintain a survival rate of at least 20% within 6 hours. If there are no surviving sperm within 6 hours, it can cause infertility. Dead sperm syndrome refers to the condition where the majority of sperm in semen are dead, but their morphology and quantity may not show any significant abnormalities. Dead sperm can cause infertility due to the loss of motility and fertilization ability.
Normal ex vivo sperm have limited mobility before semen liquefaction, but once semen liquefies, they immediately exhibit good motility. If the motility of sperm is affected by certain factors, especially the forward movement, it will prevent the sperm from swimming to the location of the egg at the optimal time, and fertilization is also impossible to occur. In addition, if sperm stay in the vagina for too long, its acidic environment will shorten their survival time. According to reports, male infertility caused by low sperm motility accounts for about 30%.
The survival time of sperm in vitro varies from person to person and is also related to the external environment. Sperm can survive for about 24 hours in ejaculated semen, and if the temperature is lowered, semen can be stored for several weeks. Here are the survival times of sperm in different environments:
1. Survival time of motile sperm in a 37 ℃ environment: 4-8 hours or more;
2. Survival time of motile sperm in the vagina: 0.5 days;
3. Survival time of motile sperm in the cervix: 2-8 days;
4. The survival time of motile sperm in the uterus and fallopian tubes is 2-2.5 days.
5. If the temperature is lowered, the survival time of sperm can reach several weeks; If frozen with liquid nitrogen, sperm can survive longer and even be stored for a long time.
So, sperm do not survive for more than 24 hours outside the body, and usually die within 2 hours.
