Birth Control Pill For Men: Gene Discovery Could Lead To Effective, Reversible Male Contraception

A team of researchers has made a breakthrough discovery, which they believe could now pave way for effective, reversible and non-hormonal male contraception.

Researchers from Washington State University (WSU) identified an expression of gene Arrdc5 in the testicular tissue of mice. When they blocked out the gene, it created infertility by impacting the count, movement and shape of sperm.

"The study identifies this gene for the first time as being expressed only in testicular tissue, nowhere else in the body, and it's expressed by multiple mammalian species," Jon Oatley, senior author and professor in WSU's School of Molecular Biosciences, said in a news release.

Arrdc5 is found in the testicular tissue of mice, pigs, cattle and humans.

"When this gene is inactivated or inhibited in males, they make sperm that cannot fertilize an egg, and that's a prime target for male contraceptive development," Oatley added.

When Arrdc5 was inhibited, it resulted in a condition called oligoasthenoteratospermia or OAT, characterized by a decrease in the amount and mobility of sperm and their distorted shape makes them unfit to fuse with an egg. OAT is the most common cause of male infertility in humans.

The study showed when the particular gene was missing in mice, it resulted in 28% less sperm production and sperm mobility was 2.8 times slower. Around 98% of the sperm produced had abnormal heads and mid-pieces.

When the gene is blocked, it does not result in any hormonal interference of testosterone, which has other crucial functions like maintaining bone mass, muscle strength and red blood cell production, along with sperm production.

"You don't want to wipe out the ability to ever make sperm – just to stop the sperm that are being made from being made correctly. Then, in theory, you could remove the drug and the sperm would start being built normally again," Oatley said.

Earlier studies have identified other molecular targets that could lead to the development of male contraceptives but the Arrdc5 gene is specific to male testes and could be found in multiple mammalian species. The next step of the study would be designing a drug based on this gene and the protein that it encodes.

The United Nations estimates more than half of pregnancies worldwide are unintended, despite the prevalence of female birth control methods. This may be because of their lack of effectiveness or availability worldwide.

"Right now, we don't really have anything on the male side for contraception other than surgery and only a small percentage of men choose vasectomies. If we can develop this discovery into a solution for contraception, it could have far-ranging impacts," Oatley added.