In 10 seconds? The female genital tract can be a hostile environment for conception, and only a few sperm will make it. Swimming in the right way is the solution but is not always happening, especially for those who have fertility issues. A new, low-cost device could help solve this problem.
Please, could you tell me more about this invention? It’s about helping couples to get pregnant. Using the natural movement of sperm, engineering researchers have developed a microfluid chip that separates healthy sperm and allows it to be used in assisted reproductive techniques. The device is easy to use (but is not meant for the home), and consists of different chambers separated by microchannels. This chip allows that motile and healthy sperm cells (i.e. those that can move) to be separated from the weak or the dead.
Why the need for separating, could you explain a little bit? Of course! Semen preparation techniques for assisted reproduction were developed to select motile (again, capable of moving), morphologically normal sperm. There are currently three lab techniques: “swim-up”, gradient techniques, and wash. The selection of the sperm will depend on the condition of the sample (i.e. how many sperm it has, and how well they swim). And the results of the preparation will influence the treatment choices and the outcome.
So, if professionals have three choices why add one more? It’s simple, researchers always are looking for optimization of protocols and to make techniques cost-effective (that means "cheaper" for most humans). The current protocols have different advantages and disadvantages. What they have in common is that they are all time- and labor-intensive, plus potentially hazardous to the sperm. (Naturally, neither the couple waiting to get pregnant nor the lab would like that). So, researchers study the rheotaxis movement of the sperm to develop new devices that allow the best sample collection and safeguard the sperm DNA’s integrity.
Wait! Rheo… what? Rheotaxis! (That’s a Greek word meaning turning to face the oncoming current. This kind of behavior helps not to be swept away). As you know sperm must swim to the egg, but how do they zone in on the target? Well, the scientific community has asked the same question. And the answer involves a complex adaptation of sperm to the female tract. As chemotaxis explains the change of direction of the sperm following some molecule (for example, progesterone ranging), rheotaxis explains the ability to swim against the flow. This characteristic helps the sperm to swim long distances (the female tract is a long, long way from “home”) from the uterus to the fallopian egg for only one of them to reach the egg.
I got it, but how is it different from the current lab procedures? The most important is that these types of models have emerged to mimic the sperm environment, so we can passively collect them, meaning without (or a least a minimum) damage. But the really important thing is that it’s cheaper and faster than the current lab procedure. Approximately, 48.5 million couples experience infertility around the globe, and male infertility contributes to 50% of all cases. In the US, the average patient goes through two IVF cycles, bringing the total cost of this procedure between $40,000 and $60,000. This kind of discovery could make the difference for a couple that is trying very hard to get pregnant.
So, is it already commercially available for patients?
Even though clinical tests with human sperm indicate a separation efficiency of 100% with high sperm quality, this type of device is still under investigation.
Researchers are hoping that this alternative method could help improve sperm selection techniques, as well as add a new tool to the armory of assisted reproductive techniques.
In this way, techniques like ICSI could be more complete, comprising selection, capture, and injection of the best sperm, hopefully helping more couples get pregnant.
Dr. Mónica Faut has distilled 8 research papers, saving you 28 hours of reading time.
The Science Integrity Check of this 3-min Science Digest was performed by Dr. Ralph Papas