Who's Afraid of Sperm Cells?

Judging from the number of users I see experiencing pregnancy scares on the Scarleteen message boards, particularly from situations besides genital intercourse, you’d think sperm cells were some magical weapon of mass fertilization, powerfully wiggling their way through clothes/towels/fabric, and leaping off hands to impregnate every person around them within a 50 mile radius. Look out for scary sperm! Get outta the way! They're coming right for you! (pun intended)

As a volunteer for Scarleteen, I'm here to tell you none of this is physically possible. It just isn't. As a former laboratory technician at a fertility clinic, having worked directly with sperm and semen (and without having ever gotten pregnant doing so, no less!), I want to tell you why.

Before I continue, a few things I'd like to clarify:

  • For the duration and purpose of this piece, I'll be using the terms "male" to indicate a human patient with a functional penis and "female" to mean a human patient with a functional uterus; "functional" in the sense that they can be used to perform the reproductive organ function(s) pertinent to this piece.
  • "Sperm cells" and "sperm" are synonymous and can be used interchangeably. The former is simply a more scientifically correct term.
  • Semen contains food and nutrients sperm need to survive. By food, I don't mean stuff we eat, like hamburgers and lettuce and whatnot; but rather, stuff human cells need to function properly, e.g. sugars, proteins, etc.

Sperm cells are essentially microscopic packets of DNA traveling via a biologically evolved wind-up key.

They’re very small, very simple, and very fragile. And no, they cannot successfully impregnate every female person they land on. If they did, there wouldn't be such thing as couples having trouble conceiving, or fertility clinics, or me working at one.

What exactly goes on at a fertility clinic, specifically, in the laboratory? In the one I worked in, I ran blood tests to determine and monitor female reproductive hormone levels and also processed patient semen.

Every person who goes to a fertility clinic does so for a different reason; while babymaking is generally the reason, I've had patients who are there to donate, to preserve samples prior to undergoing some sort of radiation therapy such as cancer, to simply doing a basic checkup after enduring an incident of bodily trauma just to make sure everything’s okay – either to assure sperm wasn't affected, or, in the case of a vasectomy, to assure there are no sperm at all (a good sign for a successful procedure).

Regardless of what they are at the clinic for, none of their samples escape the semen analysis (SA).

All in all, this is a pretty basic procedure; it's a basic checkup on the quality of the patient’s semen, kind of like how when you go to a doctor’s office a nurse usually checks you out first by taking your temperature, your weight, blood pressure, and so forth.

However, a few things are in order:

  • Sperm like to be at body temperature; in terms of numbers, that’s ideally 37°C (98°F) for optimal mobility and function. If it’s too cold (anything below 20°C, or 68°F, roughly room temperature), they get sluggish and die;. If it’s too hot (anything above 37°C, heading towards fever temperatures), the heat will cook them, causing their proteins to denature, and they’ll die that way, too.

Radiation therapy, as I mentioned above, is a form of intense heat that the body is subjected to for the purpose of killing off cancer cells because they’re so darn hardy. Unfortunately, radiation also kills off plenty of other cells in the body that are not so tough, including sperm cells.

  • Once a sample is provided, it should be processed promptly, but not immediately, preferably within 15 minutes but no longer than an hour from collection. One of the many reasons why is that there’s food and nutrients in the semen for the sperm to consume while they are (supposedly) in "transit" (towards the uterus), but it’s not an infinite amount; once the food and nutrients are used up, the sperm start to starve, and then die. (The 15 minute wait period is so that the semen can thin out from initially being so milky and gloppy, overall making it easier to work with in the laboratory).
  • Sperm also need to be kept at an optimal pH range, which is slightly alkaline (7.2 – 7.7) as protection against the harsher, more acidic environment of the male’s urethra and the female’s vagina.

As you can see, just based on these few criteria listed here, sperm can’t just simply survive anywhere in any kind of conditions, by any stretch. African violets look hardy compared to them: they are fragile, delicate little puppies, sperm.

Should you find yourself faced with a pregnancy scare scenario, especially when other logic is failing you, you might keep these criteria in mind and ask yourself:

  • Is the area where the sperm/semen/ejaculate is or was hotter/colder than body temperature?
  • Has it been sitting out for a long time, like an hour?
  • Is the area where the sperm/semen/ejaculate is chemically more acidic/alkaline than blood/spinal fluid/saliva? (I’ll admit, this one is tricky; in other words, if you’re worried about sperm surviving in stuff like a bar of soap, a can of soda, coffee, etc., rest assured that they won’t, because compared to the human body, they are simply too acidic/alkaline.)
If you answered yes to any of those three basic questions, rest assured: chances are you or someone else are not pregnant.

Two other procedures that involve semen processing also revolve around this understanding that sperm are extremely fragile and need to be handled delicately, especially if a couple is having fertility trouble and a male patient/partner is unable to produce a good sized sample.

Depending on sperm count, motility (how well they move), and the acting physician’s judgment, the laboratory prepares semen samples for either intrauterine insemination (IUI) or in-vitro fertilization (IVF) procedures.

An IUI is where the physician performs an insemination into a female patient by manually injecting the male patient’s prepared semen into her, and an IVF is where both the sperm and egg are extracted and placed onto a petri dish underneath a high powered microscope for a manual fertilization to be done before returning the now fertilized egg back into the female. In both cases, the laboratory processes the semen via a "wash," which essentially strips the raw semen of all its cells, gunk, and glory, leaving only sperm. Then they need to be reconstituted in an artificial medium that contains food and nutrients like semen so they don’t starve while they sit in the incubator, waiting to be dealt with, either through IUI or IVF. And like semen, the amount of food in there is finite, which is why reconstituted "washed" sperm also need to be processed promptly.

Sperm are so fragile that even when we (laboratory technicians) pipet the mixture up and down to thoroughly mix the sperm and media together, we have to do so slowly and gently, otherwise the force we create in the conical tube (kind of like a test tube with a screw top) is akin to a really bad storm or hurricane that can cause sperm to become dislocated or otherwise mutilated and rendered non-functional.

Sometimes sperm need to be frozen and put into storage. I’ve had to do this for patients in the military before they leave for duty, sperm donors, cancer patients about to undergo chemotherapy, and even just patients who weren’t sure they’d be able to produce a good sample on the day that their partner undergoes the insemination procedure. Given the three main criteria that I listed earlier that I stated were essential for sperm survival, there is technically no way that sperm can be frozen and still be viable after thawing, especially if they’re being dunked in liquid nitrogen! Not raw, anyway; aside from concocting a special anti-freeze of sorts to protect the sperm from a sudden change in temperature, the wash portion is essentially the same. But even so, well after the thaw, not all the sperm survive; reasons could be due to shock, weak sperm, inadequate distribution of cryogenic preservative, or a host of other reasons. Depending on how much sperm survive and are viable, either the procedure goes through, or some other change of plan needs to be enacted to ensure a good amount of sperm is put into the female for a good chance for fertilization and pregnancy.

So, who’s afraid of sperm cells?

If you were a laboratory technician working at a fertility clinic, you would have good reasons to be — not because of the potentiality of impregnating yourself, but because sperm are so delicate and require constant monitoring of three big conditions (temperature, time, and pH), not to mention the pressure you’d get from couples (and oftentimes, the physicians and the entire office) depending on you to prepare a good sample to help them make a baby.

Even if you’re someone engaging in the kind of sex that is most commonly how pregnancy happens when it does, but are also using contraception, engaging in safer sex practices, and regularly use the fabulously great resources and articles on Scarleteen--really, you have nothing to fear from sperm cells.

For more information, please check out related previously written articles on pregnancy and pregnancy scares below: