Biologically speaking, I am right in the middle of my reproductive age. That's the years between 15 and 49, when most people with ovaries are able to have children. Socially speaking, that means I'm right in the middle of roughly 30 years' worth of public commentary, suggestions and judgments about my fertility. Whether it’s regular pleas from my mum to give her grandchildren, or depictions of desperate females in movies and TV, it's a reality that is hard to escape. And let's not forget about the ads that have been following me around the internet since the age of roughly 25, promising to track my ovulation, confirm a pregnancy or let me know about places nearby where I can freeze my eggs. But what about the sperm? Why have none of my male friends or the guys I've dated been exposed to this same pressure? [Am I Normal? With Mona Chalabi] Well, we know from historical data that for generations, research into fertility has focused on poking and prodding uteruses, while our understanding of male fertility has continued to lag behind. For example, in the US, there was a 50-year gap between the founding of the American Board of Obstetrics and Gynecology in 1927 and the formation of the American Society of Andrology in 1975. And today in the US, there are an estimated five reproductive endocrinologists who mostly specialize with female patients, for every one male fertility specialist. Research into male fertility really only began to make waves in the 1990s. And since then, research has started to chip away at the persistent myth that a man's sperm is viable over his entire life. A study from 2013 found that there is a big change that happens in male fertility after the age of 34. At age 35, their sperm count begins to drop. At 40, the sperm concentration, as well as the percentage of sperm with a normal shape, begins to decline. At 43, sperm motility decreases, And from the age of 45, semen ejaculate volume begins to go down. What all of this means is that from the age of 34, there is a declining likelihood that a man will father a child through intercourse. And that probability continues to decline as they get older. Crucially, that decline exists independently of the age of their female partner. Because of research like this, a growing number of physicians are arguing that men have biological clocks, too. This is really important because most fertility research did not control for the age of the father. What this means is that so much of our understanding about how women in their late 30s are struggling to get pregnant has not taken into account that many of them are trying to get pregnant with men in their 40s. Imagine the other fertility breakthroughs that could come about with even better research -- and the effect that all of that would have on our culture and our behavior. Young couples might be able to better prepare when to have children. Guys would be hounded by ads on when to freeze their sperm, and I would have even more reason to continue to date young hot men. We've always known that it takes two to tango. Now it's time for research to give both partners equal billing.