Motherhood isn’t a universal inclination, but it discriminates by desire, not gender. Sure, self-identifying females are the most likely candidates for pregnancy, but there’s always been a small minority of males with the maternal instinct, held back by the constraints of biology. Now, uterus transplantation to treat infertility has the potential to make male pregnancy possible. In fact, transgender medicine specialist Dr. Christine McGinn has no doubt that the science — and demand — for male motherhood will become a reality very soon. If anything’s going to stop it from happening, she says, it’ll be the lack of insurance coverage to subsidize the huge cost of surgery and treatment.

McGinn, who is transgender, knows what it’s like to yearn to be a parent and be stifled by anatomy. She’s the biological mother of twins, conceived using her frozen sperm through IVF and carried to term by her female partner, as documented in the film TRANS. “We’ve come a long way in 15 years,” she told Inverse. “In 2000, you couldn’t even readily save an egg.” Now, uterine transplants are the new IVF. While researchers have yet to figure out exactly how the procedure would work in males, there’s no scientific reason why it wouldn’t be possible, says McGinn. The surgery could soon grant fertility to women and, someday, men — if insurance policies ever provide the money to pay for it.

“Most insurance companies don’t even pay for infertility,” she says. “The average cost to bring a baby into the world, if you have to have an egg donor and a surrogate, is about $130,000 to $150,000 dollars. And who has that?” Having to first surgically transplant a uterus would only raise that cost. Even more so if the recipient was biologically male.

“It’s a little bit less complicated to transplant a uterus into a biological female — it’s like swapping out an engine,” she says. But transplantation into males is possible because, anatomically speaking, males and females aren’t really that different. “What’s great about a uterus is that it’s completely regulated by hormones. A lot of its function is hormone-driven, not nerve-driven.”

Uterine transplantation, she says, has been a long time coming. One of the earliest attempts at engineering male fertility took place in Dresden in the 1930s on a transgender woman named Lilli Ebbe, whose tragic story is told in the new film The Danish Girl, on which McGinn was a consultant. In 2011, the first successful womb transplant took place in Turkey, and a baby was born to a uterine transplant recipient for the first time in Sweden last year (notably, the surgery was privately funded).

Today, if we’re going to see male uterine transplantation happen anywhere, it’ll be in nations where transgender care is covered by insurance, like Belgium and Sweden, she says. These countries are not just more likely to have surgeons experienced enough to complete a successful transplant, but they’re also more likely to have healthcare systems that will allow for them to be financially feasible. The U.S. is not one of those countries. “I’m not optimistic that will be seen in this country, and the reason is that our healthcare system is different,” she says.

McGinn maintains that her outlook is not bleak, but realistic. She foresees some Americans refusing to donate organs for transgender surgery or class divides raising questions about access to parenthood. While she’s hopeful uterine transplantation could find a become a reality in America, the most realistic path, she says, is if — or when — people realize that male pregnancy is a moneymaking opportunity. “Fertility is a big business,” she admits, though she worries that profit-seeking surgeons might someday jump into these complicated procedures without the proper training. “For so many years trans people have been experimented on and tested on, and I don’t want to see that.”

The science of fertility is progressing quickly, and ethicists and lawmakers are struggling to keep up. The important thing, says McGinn, is for everyone involved to stay focused on the ultimate goal: making parenthood possible where it was once impossible. She has never lost sight of its importance. “I’m all for insurance paying for this. I’m all for learning,” she says. “But it has to be done right.”