Four periods a year instead of twelve. That's the pitch. Chinese biologist Hongmei Wang thinks she can stretch a woman's fertile window by slowing the menstrual cycle down to once every three months. Her logic? Fewer cycles means fewer eggs burned through. More eggs left in the tank means more years of fertility on the clock. Wang runs the State Key Laboratory of Stem Cell and Reproductive Biology in Beijing, where the work isn't just academic. China's birth rate is collapsing, and extending fertility has become a national-level obsession. Here's the wild part of her argument. Women in ancestral times had roughly 100 periods in their entire life. Constant pregnancies. Years of breastfeeding. The body barely cycled. Modern women? Over 400 periods on average. Wang wants to dial that number back down, closer to how the female body operated for most of human history. Her team has already pulled off something startling. They injected human stem cells into sterile monkeys, and one of those monkeys gave birth to a healthy baby that's still alive today. A small human trial followed with 63 women suffering premature ovarian failure. Four of them ended up conceiving healthy children after stem cell treatment. But Wang isn't pretending this is simple. Suppressing ovulation also suppresses estrogen, the hormone that protects bones, the heart, and the brain. Strip it away and you trade one problem for several others. "It's one thing to prove something possible in the lab," she says. It's another thing entirely for women to actually want it. The science is real. The ethics are messier. And the question she's forcing the world to ask isn't going away. Source: EL PAÍS interview