On a recent drive to elementary school, M. told her mom: “I can’t have a baby.”

Her mother, Marlo Mack, pulled over — she had been expecting this conversation for awhile. Six years ago, M. told Mack that she is transgender and then socially transitioned to living as a girl shortly afterward — a journey Marlo Mack documented in the podcast “How to Be a Girl.” (“Marlo Mack” and “M.” are pseudonyms, the same ones used in the podcast to protect M.’s privacy.)

While the transition left M. happier and healthier, Mack had long worried about M.’s ability to reproduce as an adult and wanted to tell her daughter that scientists are working on fertility research for trans kids. But Mack also wanted to keep it light. After all, M. is only nine years old.

“From early on I’ve been kind of cringing when she’ll say, ‘When I’m a mom,’ or, ‘I‘m going to have this many babies,’ or ‘When I’m pregnant,’ those kinds of things,” Mack said. “As a parent, you don’t want your child who’s only five to have a whole aspect of human experience already shut to them.”

There are an estimated 1.4 million trans Americans, and physicians told the PBS NewsHour Weekend that demand is increasing for health care specific to them. Many doctors are confronting the issue of fertility among trans communities, especially as children start to feel more comfortable voicing their identity at earlier ages.

Gender dysphoria — the feeling that an individual’s gender is different from the one assigned at birth — can cause distress in children who fear the physical changes that come with puberty. M. was alarmed as a toddler when she learned about the possibility of someday growing a beard like her father, according to Mack.

“There was this look of shock on her face,” Mack said. “It goes to show how deeply felt and experienced gender is for these kids.”

Before that happens, some trans youth, under the care of a doctor and with the permission of a guardian, decide to take puberty blockers to halt the production of estrogen and testosterone. These drugs pause puberty while they decide how to move forward. And during adolescence, some transition with hormone therapy, taking estrogen and testosterone to develop the secondary sex characteristics of their gender.

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At this point, doctors may recommend that their trans patients preserve eggs or sperm for later use, according to Dr. Courtney Finlayson, a pediatric endocrinologist at the Ann & Robert H. Lurie Children’s Hospital of Chicago. But it’s a tricky time. If the patients haven’t gone through puberty, then their bodies have not made mature eggs or sperm yet, leaving their fertility prospects uncertain.

“You don’t have that mature biological material for reproduction,” Finlayson said. She added that fertility actions were poorly understood and rarely addressed in the past for trans people.

Drawing inspiration from cancer treatment

Twelve years ago, a group of doctors who treat cancer patients started a conversation about reproduction. Its effects are rippling through the trans community today.

The Oncofertility Consortium brought together oncologists and fertility specialists from around the country who wanted to improve fertility options for cancer survivors — including young kids whose fertility was affected by chemotherapy.

Both groups — young cancer patients and trans kids hoping to transition early — have a demand for fertility preservation at an age where it has not usually been possible. But researchers say they are drawing closer to a solution with new techniques to freeze, or cryopreserve, immature reproductive cells.

So far, scientists can take a piece of ovarian tissue, freeze it and then re-implant it into a patient to produce mature eggs. That process has resulted in at least 100 births so far, mostly by adult patients who were treated for cancer, said Dr. Teresa Woodruff, a reproductive endocrinologist researching the issue at Northwestern’s Feinberg School of Medicine in Chicago.

Yet this process does not work for all patients, and researchers say that it is unlikely to work for trans people who transition with hormone therapy. So they started to look for ways to grow that tissue in a petri dish, so it can develop into a mature egg.

In November, Woodruff co-authored a study in the journal Nature that did just that.

“We can continue to develop that technology and eventually, hopefully, this will transfer to all the individuals who are looking for fertility intervention,” Woodruff said.

The research is not as far along for people with testes, said Dr. Kyle Orwig, whose lab studies fertility at the Magee-Womens Research Institute and Magee-Womens Hospital of the University of Pittsburgh. In several animal models, researchers can preserve testicular tissue outside the body and then re-implant that tissue to produce sperm. A study published by Scientific Reports this month showed that researchers could develop sperm from mouse tissue in a petri dish over the course of 6 months, producing healthy offspring. But this technique has never been replicated in humans.

In recent years, doctors treating trans people have paid close attention to this cancer research, Finlayson said. “We have taken a lot of our inspiration and our information from the world of oncofertility,” she said.

Several years ago, Woodruff and others decided to start a committee that would focus on trans patients within the Oncofertility Consortium, as she and others were approached by doctors and trans patients who had heard about the research.

“There were trans people that were kind of finding their way to our program. And it seemed to me that this was an obvious next step for the development of fertility management,” Woodruff said. “I think for the transgender community, the more they know this is out there, the more they will take advantage of these opportunities.”

These treatments are not fully developed or available yet, and will likely not be for decades, Finlayson said. But “there is a lot of progress in that area,” she said. “We hope that 20 or 30 years from now, that this technology will exist.”

For trans patients, a taxing trade-off

Even for trans people who have gone through puberty and can preserve mature eggs or sperm, the process isn’t always straightforward. Doctors will often advise their patients to stop taking hormones during fertility treatments, which can last weeks or months.

But doctors say that even a temporary disruption in their hormone therapy can cause symptoms of anxiety or depression in their patients.

Some who decide to move forward anyway are discouraged by staff and doctors who treat them “like an alien,” said Zil Goldstein, program director at the Center for Transgender Medicine and Surgery at Mount Sinai Hospital in New York.

“A lot of adults that I see choose not to preserve fertility because it is such an anxiety-inducing experience to go in and receive what is essentially ‘women’s health care’ when you are a man,” Goldstein said. “Even staff who are aware of issues around cultural sensitivity say things like, ‘We’ve never done this with a trans person before,’ or, “This is such an interesting case, let me bring in the resident.’”

For others, the procedures required to extract sperm or eggs can cause additional distress and dysphoria. People who produce sperm may not feel comfortable masturbating to give a sperm sample, and people with ovaries may not want to undergo the procedure of obtaining eggs, which can feel invasive, Finlayson said.

“If you have to have a transvaginal ultrasound or procedure to harvest eggs, that might be something that trans males say, ‘I can’t do that,’” she said.

But Finlayson said that with more trans people seeking these procedures, doctors are learning more about how to treat them. “Fertility preservation is a major decision for everyone,” Finlayson said. “I think that we have a lot to learn about how it’s different for trans individuals.”

In general, the trans community has always relied on a medical system that was not built for them, Goldstein said.

“Traditionally in transgender health, we’ve had to borrow knowledge from other disciplines and sort of figure out how that applies to trans people,” Goldstein said. “What can be frustrating sometimes is having to adapt and extrapolate all of this information from work that is not done for trans people.”

Mack’s daughter gives advice for other trans children in this video that Mack animated.

Cost is an additional concern. Fertility preservation is rarely covered by insurance, for trans people or anyone else. And with a high rate of economic instability among trans people, many simply cannot afford it.

Orwig said the process of freezing testicular tissue can cost between $2,000 and $4,000, whereas preserving ovarian tissue costs approximately $5,000. But that estimate is “probably on the lower end,” since it applies to an experimental treatment, and would be higher in a typical clinic, he said.

“We’ve asked insurance companies, if this wasn’t research, would you cover it? And across the board, the answer was no,” Dr. Jill Ginsberg, a pediatric oncologist at the Children’s Hospital of Philadelphia, said.

Insurance coverage for trans-related care is spotty across the nation, with a wide range of laws on whether insurance must cover it. Eighteen states and Washington, D.C. prohibit insurers from discriminating against trans people, and Medicaid covers transition-related care in 12 states and the district. But concerns over trans health were magnified recently, as a federal judge in Texas blocked Section 1557 of the Affordable Care Act — which would have prohibited discrimination on the basis of gender identity — just before the regulation was set to take effect.

Mack worries about obtaining insurance coverage for her daughter — and fears the eventual cost of fertility treatments could be out of reach. “I’m worried about even just getting her coverage for basic treatment,” Mack said. “I don’t really know what I’m going to do.”

When it comes to fertility, Mack was quick to highlight that adoption is a valid path to parenthood — but she also struggles with the thought of her daughter missing out on the opportunity to be a biological parent.

“I think, well, what do I do if someday she says, ‘Mom, this was available, and you didn’t do it?’ I don’t want that conversation,” Mack said. “If this becomes available, a lot of trans people who are able to stretch to make it work are going to have a hard decision to make, and for most people it will be absolutely out of reach.”

Sitting with her daughter in the car, Mack told her she saw hope in the research progress.

“I can’t promise her that this is an option, but I can say that it’s a maybe,” Mack said.