At a time when access to reproductive health care for women is newly imperiled, the scientific press is revisiting a topic that emerges and fades into the woodwork every few years: male birth control. A new study from Michigan State University published in Nature Communications breaks new ground in approaching a male contraceptive pill.
The study has been called a “genetic foundation for male birth control.” Although the results are far from anything that could be used in humans, they lay solid groundwork, according to Peter Schlegel, chief of urology at Weill Cornell Medical College in New York.
The scientists found that by shutting off a pathway using CRISPR gene editing, they could stop sperm production in mice. The gene they spliced out codes for an enzyme that makes sure sperm cells are made correctly, and its removal rendered the mice sterile.
While translating results from mice to men can be tricky in most research, according to Schlegel, rodents are great for sperm. When it comes to sperm production, he says, rats and mice are far more efficient than humans. So if an intervention can stop sperm production in a mouse, it’s almost a guarantee that it can do the same in humans.
Still, this study provides, if anything, a very preliminary road map. The gene that the researchers spliced out of the mice is part of a pathway that drug developers could target. Of course, as Schlegel notes, most people taking a birth control pill would probably want to be able to produce sperm again at some point.
“You’ve got to stop production of 100 million sperm in a day without knocking out potential for production in the future,” he says.
In addition to not sterilizing a person, an effective male birth-control drug would have to leap over some other biological hurdles. To do its job, a pill taken by mouth would have to overcome the “blood-testes” barrier, which safeguards the testicles from much of the…