Smartphone attachment that can test sperm with 98% accuracy developed
Researchers are targeting a price point of less than 50 dollars (£40)
A cheap smartphone attachment has been developed that can check the child-conceiving potential of a man's sperm.
The clip-on device, which cost under £4 to assemble, is intended to make assessing male fertility as simple and quick as pregnancy testing.
It is expected to provide helpful answers to millions of couples confused and upset by their inability to have children.
But the ability to test a semen sample with your phone in under five seconds could also give rise to some difficult social situations as women add sperm quality to their prospective partner check list.
In early tests, the gadget detected abnormal sperm samples with an accuracy of 98%.
Dr Hadi Shafiee, from Brigham and Women's Hospital in Boston, US, said: "We wanted to come up with a solution to make male infertility testing as simple and affordable as home pregnancy tests.
"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 analyse a video of an undiluted, unwashed semen sample in less than five seconds."
The team put the device together using spare parts from DVD and CD drives at a total cost of 4.45 dollars (£3.57)
Testing sperm simply involves drawing semen into a disposable holder that is plugged into one side of the phone attachment, USB-style.
In seconds, results of the analysis are displayed on the phone's screen.
To evaluate the system, the research team recruited 10 volunteers with no formal training, including administrative assistants employed at a Boston fertility clinic. They correctly classified more than 100 semen samples.
Overall, the scientists examined 350 clinic samples and were able to identify those with low sperm counts and inactive, or poorly motile, sperm with 98% accuracy.
Co-author Dr John Petrozza, director of the Massachusetts General Hospital Fertility Center, said: "The ability to bring point-of-care sperm testing to the consumer, or health facilities with limited resources, is a true game-changer.
"More than 40% 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."
Around the world, more than 45 million couples are believed to be affected by infertility. Male infertility is understood to play a role in roughly 40% of those cases.
A man is said to have a low sperm count when one millilitre of his semen contains fewer than 15 million sperm. Motility is classified as low when less than 40% of sperm are active.
In the UK, GPs normally arrange male fertility tests. Home testing kits are available, but evidence of their reliability is lacking.
The smartphone male fertility test is described in the journal Science Translational Medicine.
Leading fertility expert Allan Pacey, Professor of Andrology at the University of Sheffield, said: "One of the first medical tests undertaken to evaluate the fertility of a man is an examination of a sample of his semen to measure the number of sperm he produces, and work out how many of those are swimming.
"However, the techniques involved in doing this haven't really changed much since the 1950s and moreover they are often only available in specialist centres and are frequently prone to errors if not carried out correctly and by someone with sufficient training.
"As such, the development of an easy, cheap and accurate method to evaluate the sperm present in a sample of semen would be very welcome, particularly if it could be carried out by someone without specific training and in any location."
He pointed out that the smartphone device could not replicate all the tests carried out in a specialist lab and did not analyse morphology - sperm size and shape.
He added: "For a small number of men whose sperm are badly made, and have poor morphology, it would be important to get this diagnosed correctly.
"So any man who struggles with infertility for a significant length of time, say more than 12 months, should consider getting their test repeated in a specialist laboratory, regardless of what the phone app might have concluded."
A spokesman for Brigham and Women's Hospital said the team planned to commercialise the product and were looking at potential business partners.
It was hoped the device will receive regulator approval from the US Food Drink Administration (FDA) in less than two years.
"The researchers are targeting a price point of less than 50 dollars (£40)," the spokesman added.