Ever wondered how long sperm can survive in various environments outside a male's body? It's time to find out more.
Reproduction is a truly fascinating subject, even without all the naughty bits that people associate with it. It’s something that every living thing has in common, from single-cell organisms to plants and animals. Humans are even attempting to take the next step forward, with same-sex reproduction research [1].
At this point in time however, human reproduction still typically requires a biological male and female. It’s safe to say that everyone knows how the process works, eventually ending with one sperm penetrating the egg and fusing with it to form what will become the foetus. This cellular tag team and process is something that all humans and animals share.
Human males produce millions of sperm per day, but it’s still important to know which circumstances allow them to thrive and what environments are deadly for them. Here’s everything you need to know about the male reproductive cell (aka sperm) and how couples trying to conceive (TTC) can boost its chances of survival.
Disclaimer: The information provided in this post is not intended as medical advice.
Sperm 101
As mentioned above, sperm is the male reproductive cell. Its female counterpart would be the egg and when fertilisation is successful, they’ll form a zygote and develop into a foetus. Sperm is produced in the testicles and quite a bit is made on a daily basis. Just how much? Well, every millilitre of semen contains 20 to 300 million of them [2].
Sperm cells consist of 3 parts: the tail, midsection, and head. Each part plays an important role for fertilisation and the sperm’s survival. The sperm’s tail enables it to move while its midsection provides energy for the entire cell [3]. As for the head, it contains DNA and its tip is covered by an organelle dubbed acrosome (think of it as a ‘helmet’ of sorts), allowing it to penetrate the egg safely [4].
The quality of a sperm cell does impact fertilisation, with several factors at play here. The first would be how well a sperm can move, which is known as sperm motility [5]. The second factor would be sperm morphology — the sperm cell’s shape, size and structure [6]. The final factor would be the DNA contained in the sperm’s head [7].
How long does sperm live outside the body?
The outside world isn’t exactly friendly to sperm because it requires nutrients and favourable conditions to survive [8]. Once semen dries up, the sperm that it contains will definitely die. This means that sperm has a lifespan of just several minutes outside the body after ejaculation occurs. However, under the right conditions, these cells can live for up to several days.
More on these ideal conditions below.
How long can sperm survive inside a woman’s body?
As mentioned earlier, nutrients and favourable conditions are a sperm’s best friend. Fortunately, there’s plenty of that in a woman’s vagina, cervix, and uterus. However, a large number of sperm perish in the vagina because of the acidic environment in the lower vaginal tract [9]. On the bright side, semen forms a protective gel around the sperms to protect them as they make their way up the vaginal tract [10].
Once they have entered the cervix and uterus, the surviving sperms can live on for up to five more days [11]. Their final task is to collectively ensure that one of them successfully penetrates the egg in the fallopian tube to fertilise it. From there, the fertilised egg will descend into the uterus and eventually become the foetus.
To give your partner’s sperm a higher chance of survival, do consider using the twoplus Fertility Applicator. This fertility home insemination kit is specially designed for easy use in the privacy and comfort of your own home. It works by allowing you to deposit sperm higher up the vaginal tract and bypassing its acidic environment in the lower region.
How harmful are hot tubs to sperm?
Because of the temperature that hot tubs are regulated to (approximately 40°C) and the chemicals that are present in them, like bromine, sperm die seconds after ejaculation [12]. Thus, it is highly unlikely that they’ll be able to make their way through the water into a woman’s vagina.
This applies to warm baths too, it is almost not possible for sperm to make their way through the water into a woman’s vagina. However, their lifespan is longer here as it’s simply warm water, unless it’s a bubble bath or if things like bath salts are added to the tub. On the other hand, having semen floating in the bath wouldn’t be any couple’s idea of a fun time.
That being said, ejaculating directly into the woman’s vagina negates everything mentioned above. This is because the sperms are entering an environment that’s more hospitable for them right away. They won’t be exposed to the hot water and/or chemicals present in the surroundings.
How long can sperm live after it’s frozen?
Although sperm thrive in moist and warm environments, they can be frozen for long-term storage at a sperm bank or fertility centre. In fact, this fertility preservation practice has been successfully performed since the 1950s. Home sperm banking kits are becoming increasingly available these days, but they are still seen as a last resort [13].
Sperms that are correctly frozen are able to survive indefinitely, if the facility’s temperature is well-maintained [14]. During this period, sperms are suspended in animation and they aren’t using any energy. Furthermore, the sperms cannot be attacked by bacteria or other cells due to the low temperature that they’re being stored in.
However, the thawing process has not been perfected yet. The effectiveness of sperm that has been thawed is the same as fresh ones but not all make it out alive. A 2019 study in China found that the survival rate ranged from approximately 74-86% after 15 years of cryopreservation [15].
Ways to improve sperm health
As you can see, the environment that sperms are exposed to drastically affects their survival rate. However, the environment that’s most pertinent to sperm would be a woman’s reproductive system. To maintain and boost the health of your sperm, and give them a better chance of reaching the egg, here’s what you can do.
Firstly, leading a healthy lifestyle gives your sperm health a huge boost. Managing your stress levels, eating well, including vitamins and supplements into your diet, maintaining a healthy weight, and getting regular physical activity are all constituents of a healthy lifestyle. When combined, these go a long way toward improving your sexual function and overall sperm parameters [16].
Additionally, cutting out cigarettes and alcohol improves your sperm health as well. With regards to the former, smoking causes a decrease in sperm concentration, motility, and morphology [17]. As for the latter, excessive alcohol use can affect sperm quality [18]. Removing alcohol from the equation nips the problem in the bud.
For couples TTC, give your sperm an added edge by using the twoplus Sperm Guide. This soft and flexible fertility product for men and women is made of 100% medical-grade silicone and reduces semen leakage after sexual intercourse. It also allows you to naturally deposit and retain sperm closer to the cervical opening, avoiding the acidic region of the lower vaginal tract.
In closing
The world is generally a perilous place for sperm. Even one part of the female reproductive system (aka the lower region of the vaginal tract) has the potential to kill off a fair number of sperms. Then there are places like hot tubs, which can kill sperms in seconds.
Fortunately, there are ways to keep sperm alive for longer than a few minutes and practices that you can adopt to maintain or boost your sperm health. Case in point: Healthy lifestyle changes that include abstinence from smoking and alcohol. Also, at-home insemination kits like the twoplus Sperm Guide may help boost your chances of conception.