When two transgender men recently broke their silence and spoke publicly about how they had coped as “breastfeeding parents” it spiked an interest in just what it takes to be a lactating man.

The two, Trevor McDonald from Canada and Evan Hempel from Massachusetts in the US challenged stereotypes of parenting and of breastfeeding when they became part of a public discourse on transgender parents.

Chestfeeding – as its become known –  is when a trans man—someone who was assigned female at birth but has transitioned to male gives birth and lactates to feed his baby.

Canadian father Trevor MacDonald has chestfed two babies.

He wrote about it in his book Where’s the Mother: Stories from a Transgender Dad, although MacDonald had chest surgery as part of his transition, he was still able to breastfeed his children.

He said that he faced the same problems many do during breastfeeding – of low supply and trouble feeding when his baby felt unwell, but with the help of  many "incredibly generous parents" who helped by donating breastmilk to top up his supply he managed to successfully breastfeed both children.

McDonald explained in his book that some trans men experience chest changes during pregnancy even if they have previously had chest surgery. They can experience engorgement and mastitis regardless of the feeding method they choose.

"Some trans men experience no problems at all with chestfeeding and find it to be straightforward and satisfying," he said.

His journey was echoed just a few months later when Jessi Hempel wrote about her brother, Evan’s emotional journey into fatherhood for Time Magazine.

“My brother Evan was born female. He came out as transgender 16 years ago but never stopped wanting to have a baby. This spring he gave birth to his first child,” Hempel writes.

She shared an amazing photograph of Evan feeding his newborn son. He told his sister that chestfeeding was a gamble.

“I didn’t know how I’d feel, but it turns out I just feel like it’s really cool that my body can do this.”

Since the stories of these two remarkable parents became public, interest in chestfeeding is growing.

Cosmopolitan spoke to Dr. Scott Mosser, a cosmetic surgeon in San Francisco, whose work primarily focuses on chest and body contouring surgery. He explained that chestfeeding accommodates those who undergo a transgender mastectomy or an FTM top surgery.

Depending on the amount of loose skin and breast tissue, the FTM top surgery can be one of three procedures: keyhole surgery, periareolar surgery, or a double incision procedure, but having the surgery doesn't eliminate the possibility of breastfeeding.

Milk production might be lower, like McDonald experienced and practicalities like clothing might occur, but the biggest issue, Dr Mosser explained is the heteronormative medical system.

In a recent edition of BMC Pregnancy and Childbirth chestfeeding was for the first time described in an academic paper.

It was Trevor McDonald’s experience – along with a group of lactation experts, nurses, midwives, and researchers - that informed a research paper, Transmasculine individuals’ experiences with lactation, chestfeeding, and gender identity.

MacDonald and his team interviewed  22 participants who self-identified as transmasculine and who either were or had been pregnant “with a goal of describing and interpreting patterns and themes that emerged” reports The Atlantic.

Of the 16 who chestfed their babies nine of these chestfeeders reported no gender dysphoria—defined by the study as “the experience of distress or anxiety regarding one’s gender and body.” But two of the participants who initiated chestfeeding reported having to stop as a result of “overwhelming gender dysphoria.”

Several spoke of how doctors contributed to feelings of dysphoria by referring to them with female pronouns.

One man, Emmett, described the practical issues he faced.

“I was producing a ton of milk. … I didn’t have anything ready socially, either. I didn’t have any zip-up binders. I had no way to stop the milk from leaking through my chest. I had no appropriate … male clothes for nursing.”

The researchers found that there was a lot of be done to create a safe space for the chestfeeding community, including the “kind of education that obstetricians, midwives, and lactation counselors receive” as well as the “terminology” surrounding lacation that is at the moment gendered female.

McDonald has called for future research on the impact of chest-masculinization surgery on lactation and milk production, as well as more discussion by doctors on the potential for future chestfeeding before performing top surgery on patients.

Overall he says we need to show “more nuance, more complexity” about transgender lives, that he says” is what is most important in this study.”