When Emmett Hardiman transitioned at age 18, he didn’t think he would ever have his own child. At the time, doctors told the transgender man that long-term testosterone use would probably ruin his reproductive organs, along with any chance of having kids.

“It was very much the belief that you could only be on testosterone for so long before you had to get everything removed or you would be very high risk [for cancer] or you were definitely going to be infertile,” Hardiman, 29, told NBC News.

Now, research is giving fertility experts insight into the true impact of testosterone use on fertility.

"I think there is a giant myth that testosterone turns your ovaries into papier-mâché ... and I think these studies that are coming out are saying that’s not true, actually. Actually, they are more like hibernating." Dr. Johanna Olson-Kennedy

A recent study from Boston IVF, a fertility clinic and research organization, based on eight years of patient data, revealed that transgender men who stopped taking testosterone for an average of four months had similar egg yields to cisgender (nontransgender) women when undergoing ovarian stimulation.

“The numbers were very small (about 25 patients in total), but it was very reassuring that even though these transgender men had taken testosterone, when they stopped it and were treated, they responded well and we had good outcomes,” said Dr. Samuel Pang, a reproductive endocrinologist and medical director at Boston IVF.

It’s unclear how many trans men give birth or have their eggs frozen in the U.S. In Australia, where government agencies have tracked both sex and gender in official records since 2013, 54 transgender men gave birth in 2014, according to data from the country’s universal health care system. A Dutch study published in the journal Human Reproduction in 2012 found that a majority of trans men reported wanting families.

If possible, trans men who know they want to have children should get their eggs frozen prior to transitioning, according to Pang. For one, it’s unclear what effect long-term testosterone use might have on eggs and embryos, even if the person goes off hormone treatment prior to fertilization. However, he added, there have been no reports thus far of harmful side effects to children born to those who have taken testosterone.

He added that gender dysphoria is another reason to freeze eggs prior to transition.

“I have seen a lot of transgender men who come in, they’ve already transitioned, they’ve already started testosterone,” Pang said, but “the thought of stopping testosterone or going through hormone treatments is very daunting for them, so they frequently will not pursue it because of that.”

‘I had to make a choice’

Hardiman, an attorney who lives in Cranston, Rhode Island, said he believed that transitioning would prevent him from ever having his own kids. At the same time, the gender dysphoria he suffered since childhood — the distress many trans people feel over the mismatch between their gender and sex assigned at birth — was severe. Throughout high school, he wore baggy clothes to conceal his developing body, and started to self harm. Though he feared the impact it might have on his fertility, he said he began making plans to transition as soon as he turned 18. “I had to make a choice,” Hardiman said.

Emmett Hardiman with his two daughters. Courtesy Emmett Hardiman

But his fear turned out to be unwarranted. At age 21, he lost his health insurance when his father died, and was forced to discontinue his hormone treatment. Hardiman’s period soon returned. By then, he was married, and decided to get his eggs harvested so his wife, Calla, could get pregnant with his child through in vitro fertilization. Now, he is a father to two daughters, ages 3 and 6.

“I mean there is definitely a hard, difficult choice either way,” he said of his decision to undergo fertility treatment. “Just having to go off testosterone in order to do IVF was not a great option, but it was to me better than the alternative.”

According to Dr. Johanna Olson-Kennedy, medical director of the Center for Transyouth Health and Development at Children's Hospital Los Angeles, it’s not uncommon for young trans men to be unsure about their fertility options, since there has been little data on it until now.

“I think there is a giant myth that testosterone turns your ovaries into papier-mâché,” she said, “and I think these studies that are coming out are saying that’s not true, actually. Actually, they are more like hibernating.”

“Now, when people are making these decisions to either carry their own children or harvest, they will come off of testosterone and their body kicks in,” Olson-Kennedy continued. “They start ovulating, having menstrual cycles, and then they go through harvesting procedures or whatever they decide to do.”

Still, many trans men may struggle with dysphoria around having their own children, even if it’s what they want.

“It does still seem like there is either a fear that their reproductive systems won’t work because of testosterone, or there’s that feeling that carrying a child would devalue their existence as a man,” said Chris Rehs-Dupin, 36, a parking enforcement officer who lives in Columbus, Ohio.

Rehs-Dupin, who is trans, said he made the decision to have his own child before he transitioned. One reason, he said, was because he wasn’t sure what impact testosterone might have on his ability to have children later. Another reason, he said, was because his wife was struggling with infertility at the time, and they desperately wanted their own biological child.

“I realized I could do this; there was nothing keeping my body from doing it,” said Rehs-Dupin, who gave birth to a daughter, now 5 years old, through IVF in 2014.

Informing trans youth about fertility options

As transgender individuals start to transition at younger ages, many questions remain about how hormone blockers may potentially impact their fertility as adults.

Hormone blockers, which are used to delay puberty in trans youth, do not cause infertility, experts say — their purpose is to buy these teens some time while they decide whether transitioning is right for them. But if a teenager who has been on puberty blockers moves on to cross-sex hormones without first going through an endogenous puberty, the reproductive organs won’t have a chance to fully mature. However, if a trans man who takes this path does decide at some point in adulthood to go off testosterone in order to have children, he should, in theory, be able to go through an endogenous puberty, according to Olson-Kennedy. But since hormone blockers are a relatively new treatment, experts can only speculate.

“We don’t know because no one has ever done it,” she said. “I mean, it stands to reason that somebody would, because your hypothalamus doesn’t change — you’re still secreting the same hormones that you would otherwise, you’re just significantly delayed.”

According to the guidelines from the World Professional Association for Transgender Health, Fenway Health and the Endocrine Society, among other health organizations, providers should advise trans patients — both adults and youth — about the potential impact to future fertility that transition-related care might have as part of the informed consent process, and brief them about their reproductive options before treatment.

There is little data on how often trans youth and their families seek fertility preservation. While surveys indicate these young individuals receive a wide range of counseling on the matter, one study found that only 13 percent were referred to fertility preservation clinics, and that a disproportionate number of them were transgender girls (assigned male at birth), according to a 2019 report from the journal Pediatrics.

According to the same study, transgender youth showed a mix of interest in possible family building options, including both the ability to eventually have their own children and adopt, while other studies found lower rates of interest in having children among these youth. Half of them, however, questioned whether their feelings might change as they got older.

Fertility experts usually recommend trans youth who want to undergo fertility preservation temporarily stop treatment in order to freeze eggs or sperm. But a recent case report from the University of Pittsburgh Medical Center suggests that going off hormone blockers may not always be necessary. According to the report, published last year, a 16-year-old trans boy was able to have his eggs preserved without stopping hormone blockers. Five of his eggs were harvested, and four were successfully preserved, according to the report, published last year in the New England Journal of Medicine.

While it was only one case and the retrieval was small, the findings were significant, considering more people are transitioning earlier in life, according to Dr. Stephanie Rothenberg, the fertility doctor who treated the teen. But she said the procedure still posed challenges for a young person, who was struggling with dysphoria. The teen was unwilling to go off blockers, she said, and required extensive counseling over a period of several months to prepare him for potential side effects.

“It was a big discussion with a lot of counseling and just making sure that everybody was on the same page about the fact that we just didn’t know what was going to happen,” said Rothenberg, who is now at Pacific NW Fertility in Seattle.

While the teenager remained on hormone blockers, he did experience one period and developed a small amount of breast tissue during the fertility process, she said. And while it was his choice to undergo treatment with his parents’ support, she said the teen still struggled with dysphoria.

“He has several mental health care providers, so we were able to coordinate support for him; he also had an extraordinarily supportive family,” she said. “But I think that he felt prepared that that was going to happen, and then ultimately, it was very challenging for him.”

In an email to NBC News, Pang said the results of the Pittsburgh case study are “new and encouraging information” for dysphoric teenagers who wish to preserve eggs, but he said the sparse number of eggs retrieved are unlikely to result in a future baby.

“Until there are more cases reported, and until cases which ultimately result in successful pregnancy and live births are reported, I continue to have significant concerns about whether fertility preservation can truly be accomplished while these pre-pubertal teens are treated with puberty suppression drugs,” he wrote. “The bottom line is that fertility preservation isn’t just about being able to freeze a few eggs; fertility preservation is the ability to freeze eggs which can ultimately be used successfully to achieve a successful pregnancy and live birth of a healthy baby.”

Transgender girls may be able to have sperm preserved prior to hormone treatment, depending on the progression of endogenous puberty at the time, according to Rothenberg. In an email, however, she said there have been no reports to date of any attempting to preserve sperm while on hormone blockers, and that success would likely be “quite low” unless blockers are discontinued.

While the impacts of hormone treatment on fertility remains uncertain for these teens, specialists who work closely with trans youth stress the importance of the mental health benefits they offer. Not only do these treatments prevent them from having to undergo unnecessary surgical interventions in the future — such as mastectomies and facial feminization surgeries, which cost thousands of dollars — they help reduce youth suicide attempts and depression, and give them the ability to function at school free from discrimination and the constant nagging of their own dysphoria. These benefits, experts argue, should not be outweighed by concerns over fertility. Such concerns, according to Olson, are often “rooted in the idea that procreation is the most important thing about somebody’s life.”

“That’s not true for a lot of trans people,” she said. “I’m not saying it’s not important — I’m not certain that it is more important than people have the opportunity that blockers bring them.”

High out-of-pocket costs for fertility care

For trans dads, there are many routes to fatherhood.Some trans men may become pregnant unintentionally, believing that testosterone treatment will prevent pregnancy (testosterone does not completely block ovulation, especially if it’s not being taken regularly). Others may temporarily halt testosterone to get their eggs frozen in the hope that a female partner or surrogate will someday carry their child through in vitro fertilization. Some may decide to get pregnant intentionally before or after their transition (stopping testosterone temporarily if that’s the case). Others may choose to adopt. And many never desire to have children at all.

Chris Rehs-Dupin, his wife and their two children. Courtesy Chris Rehs-Dupin

Rehs-Dupin, who transitioned shortly after his daughter was born, said he decided to get pregnant only because his wife was unable to do so at the time. He said pregnancy did not make him feel dysphoric, but he feared how other people would judge him.

“I feel like I was put in the position where it was just like this isn’t even going to happen because it’s not what’s supposed to happen,” he said of his struggle over the decision. “Like, this is my wife, she wears dresses, she should carry the babies. I want to be a man, I’m going to be a man, I shouldn’t do it. It took her not being able to carry for me to be able to have one of the most important and valuable experiences of my life, and I just feel like society doesn’t set us up to make that decision.”

Still, the cost of fertility preservation poses major obstacles for gender dysphoric patients regardless of where they are on their path to parenthood or transition.

Only 10 states (California, Colorado, Connecticut, Delaware, Illinois, Maryland, New Hampshire, New Jersey, New York, and Rhode Island) have laws that explicitly require health insurance plans to cover fertility preservation for patients who may lose their reproductive capacity due to treatment for a medical condition. While cancer treatment is the most common, these laws typically also apply to treatment for gender dysphoria, according to David Farmer, a spokesman for the National Center for Transgender Equality. Similar bills have been proposed in several other states, and a federal bill — the Access to Infertility Treatment and Care Act — has also been proposed, he said. Introduced in 2018, the federal measure would require private health insurance plans covering obstetrical services to include infertility treatments, and would extend coverage to federal employees, members of the U.S. military and veterans.

“In addition, federal and state laws prohibit discrimination based on sex (including on the basis of transgender status), disability, and other arbitrary factors. If a health plan covers fertility preservation when treating some medical conditions but not others, that could potentially constitute discrimination,” Farmer said in an email. “Unfortunately, many health plans still do not cover fertility preservation, including Medicare, military and veterans’ health systems, and federal employee plans.” The Access to Infertility Treatment and Care Act, if passed, would change that, he added.

As a result, few health insurance policies cover fertility treatments for trans men, and they often pay hefty out-of-pocket costs to have their eggs frozen. A single fertility treatment, on average, costs about $15,000, with an added cost of $275 a year for egg storage. What’s more, there is no guarantee that the treatment will result in pregnancy.

“That’s the biggest thing, especially when they are paying out of pocket, and we’re using thousands of dollars worth of medication,” Rothenberg said. “That’s a big risk that they have to take.”

Hardiman said he and his wife paid over $20,000 out of pocket for their fertility care, but he said his kids are worth it.

“It’s unreal,” Hardiman said of his son and his daughter. “Sometimes I look at them and can’t even believe it. They are just miracles and both awesome.”

Follow NBC Out on Twitter, Facebook & Instagram