Researchers say they have created an accurate, convenient test that men can use to determine the fertility of their sperm.

It is currently estimated that worldwide infertility affects 45 million couples.

About 40 percent of these cases are attributable to the male partner.

In the United States, approximately 1 in 8 couples cannot conceive and a third of these cases are attributed to male infertility.

Current infertility diagnosing practices are expensive and can only be carried out in a clinic or hospital.

However, a team of researchers at Brigham and Women’s Hospital (BWH) in collaboration with Massachusetts General Hospital (MGH) – both in Boston – have designed a new, inexpensive, and simple tool for diagnosing male infertility.

The new device, which hasn’t been named yet, is smartphone-operated and can be used from home.

Using motility and sperm concentration criteria, researchers said the new device analyzes and measures semen quality, ultimately identifying infertility with a degree of 98 percent accuracy.

Manoj Kanakasabapathy led the research team that designed and tested the device. The findings were published in the journal Science Translational Medicine.

The sperm analyzer is made of an optical attachment that connects to both a smartphone and a device onto which users can load a sample of their semen.

The semen sample device is disposable and uses a microchip with a capillary tip.

Users are guided by the app through each stage of the testing process. Additionally, a weight microscale – connected wirelessly to the smartphone – measures the total sperm count.

Hadi Shafiee, Ph.D., a principal investigator in the Division of Engineering in Medicine and Renal Division of Medicine at BWH and co-author on the study, explained the team’s motivation:

“We wanted to come up with a solution to make male infertility testing as simple and affordable as home pregnancy tests,” he said. “Men have to provide semen samples in these rooms at a hospital, a situation in which they often experience stress, embarrassment, pessimism, and disappointment. Current clinical tests are lab-based, time-consuming, and subjective. This test is low-cost, quantitative, highly accurate and can analyze a video of an undiluted, unwashed semen sample in less than five seconds.”

To test the accuracy of the device, Kanakasabapathy and team collected and analyzed 350 clinical semen samples from the MGH Fertility Center.

The World Health Organization (WHO) define normal sperm concentration as higher than 15 million sperm per milliliter, and normal motility – or the ability of the sperm to move – as more than 40 percent.

Based on these criteria, researchers said the device detected infertility with 98 percent accuracy.

The researchers also wanted to test how user-friendly the device is, so they assessed its use by both trained and untrained volunteers.

A total of 10 users with no training correctly categorized more than 100 sperm samples as fertile or infertile.

The researchers think that the new tool will benefit a variety of people.

Men who have undergone a vasectomy can use the home-based device to monitor their sperm several months after surgery. At the moment, vasectomy patients are required to check in regularly with a urologist to make sure the surgery was successful, but the new device could make this practice obsolete.

Additionally, the new device could serve as a point-of-care testing tool, which could be used not only at the patient’s home but also in the hospital or other locations.

Finally, the authors suggest the device could also be used to test fertility in animals.

“The ability to bring point-of-care sperm testing to the consumer, or health facilities with limited resources, is a true game changer,” says Dr. John Petrozza, study co-author and director of the MGH Fertility Center. “More than 40 percent of infertile couples have difficulty conceiving due to sperm abnormalities and this development will provide faster and improved access to fertility care. […] We have really been able to create a product that will benefit a lot of people.”

The new device is currently only a prototype, but as soon as the researchers carry out further tests, they will apply for approval from the U.S. Food and Drug Administration.