How long does sperm live outside the body?
A sperm’s life cycle outside the male body begins at the moment of ejaculation. Some die within minutes, and some can live anywhere up to seven days, under perfect conditions. But most live about two or three days inside the female reproductive system, according to USC Fertility.
Typically, one ejaculation contains up to 500 million sperm, according to the University of California, Santa Barbara (UCSB). You need just one sperm to make it to the right place — the correct fallopian tube — at the correct time — after ovulation — to create a new life.
This makes it seem like pregnancy could occur very easily. It often does, of course, but most sperm die before making it to their final destination, according to the American Pregnancy Association. Understanding how long sperm live — inside and outside the body — can help whether you are trying to get pregnant or trying to avoid getting pregnant.
The sperm’s journey to the egg
The goal of a sperm is to swim through a woman’s cervix and uterus to end in the fallopian tube in search of an egg. It isn’t as easy as it sounds. During this process, sperm cells face many obstacles, and with each obstacle, the sperm count goes down. Out of the half-million sperm that started out on the journey, relatively few actually reach the woman’s egg — if there even is one available at that time.
How long does sperm live if it’s outside the woman’s body?
When a sperm ends up outside of the woman’s body, it lives only a few minutes. Sperm needs moisture and warmth to live, so once exposed to air, they quickly die. As soon as semen dries, the sperm within it dies.
This might lead to the idea that “pulling out” before ejaculation can prevent a pregnancy, but that isn’t always the case. Pre-ejaculation fluids can contain sperm and can be left inside the vagina before you pull out, according to UCSB. Additionally, semen that is close to the vagina where there is warmth and moisture can live up to 20 minutes and can still make it inside. The pull-out method is ineffective because pre-ejaculation fluid contains sperm and it is difficult to anticipate when that fluid will be released and thus avoid sperm in the vagina.
Can sperm survive in a hot tub?
Because sperm need moisture and warmth to survive, it is
possible for sperm to live when ejaculation occurs in a hot tub, but they only
survive for a few seconds according to UCSB. The chances of becoming pregnant in this way are very slim.
The ratio of water to sperm is quite high ,and the chances of a sperm making it
through the water and into the vagina is low. Besides, any chemicals, soap, or
suds in the water are likely to kill the sperm.
How long is there a risk of pregnancy when the man ejaculates in the woman’s vagina?
During vaginal intercourse, sperm is deposited in the acidic vagina according to the UCSB. This atmosphere kills the sperm that don’t make it to the cervix within hours. During ovulation, the pH of the reproductive tract becomes less acidic and sperm might live a little longer, giving them extra time to swim upward toward the cervix.
Sperm that make it to the cervix and uterus have a longer life. They can live there up to five days, according to the American Pregnancy Association, although most will die within one to two days. Here, cervical fluids work to propel the living sperm through the uterus and into a fallopian tube. Some experts believe that the cervical fluid acts as a filter, allowing the most motile sperm through while stopping less motile sperm.
Finally, some sperm make it to a fallopian tube. Although a few thousand might make the complete journey there, only a few will find an egg. The rest die during the search, according to UCSB. The average life of a sperm that makes it to the fallopian tube is three to four days, although some can live as long as a week. That means an egg making its way through the fallopian tube during that time could be fertilized, potentially leading to a pregnancy.
But what about the lifespan of an egg? If as perm does make it to the fallopian tube, it must fertilize the egg within 12-24 hours of the egg’s release from the ovary in order for pregnancy to occur, according to the American Pregnancy Association.
What to do if you believe you’re at risk of unwanted pregnancy
Think you may be at risk of unintended pregnancy? Emergency contraception is available. There are several options available, including over-the-counter pills, like Plan B (although you don't need a prescription, you just need to ask the pharmacist for it), and even the copper IUD (which a physician must insert). No matter which option you choose, it should be taken as soon as possible after unprotected sex. For example, Plan B One-Step should be taken within 72 hours after sex. But the sooner you take it, the better it works.