Seth Marlow, 41, from Virginia, originally transitioned from female to male when he was 25, and at the time assumed he was giving up the chance to have his own biological children.
But when he and his wife Leah, 37, decided to start a family, Seth switched his hormone intake from testosterone to oestrogen so he could produce eggs once again.
Sharing his journey to fatherhood on the podcast Pregnantish and in an interview with the New York Post, Seth revealed the couple were able to freeze several embryos using Seth's eggs and donor sperm.
The embryos were frozen for around three years until the couple were ready to become parents, when one was implanted in Leah’s uterus, resulting in a healthy pregnancy and the birth of their son Arlo, now four.
“Arlo has two genetic fathers,” Seth told the NY Post. “He’s a pretty unique kid.”
The dad-of-one said he transitioned in 2003, having a double mastectomy and taking testosterone, but his ovaries remained intact.
In order to start ovulating again, he had to switch the testosterone he was taking for oestrogen, but although the hormone had the desired effect, it had other implications for his body
As a result of the oestrogen Seth’s body redeveloped curves, and after three months he got a period.
According to Marlow, the transition “took quite a psychological toll on me”, but he was “determined to see it through.”
Their parenthood path was also costly, as a refusal from the couple’s health insurance to cover the transition meant the couple had to pay “around $30K (approx £23K) out of pocket for the in-vitro fertilisation procedure”, according to the NY Post.
The embryos were frozen for three years before Leah underwent two rounds of IVF, eventually resulting in Arlo, a six-pound, three-ounce baby boy who was born in October 2015.
Though their son is still too young to understand the ins and outs of baby-making, he does know that he came from his dad's egg, and has asked his parents whether they'll use another of dad's eggs to give him a baby brother or sister.
And extending the family is something the couple are considering – they have 13 embryos in the freezer.
“It’s a beautiful way to make a family,” Seth adds.
The Pregnantish podcast airs every Tuesday.
Earlier this year another transgender man opened up about his journey to parenthood.
Freddy McConnell, 32, also had a child using a sperm donor, and gave birth to his son while legally classified as a man.
Like Seth, he had to come off his testosterone hormone treatment in order to conceive his son.
McConnell began his transition from female to male at the age of 25.
He took testosterone and had his breasts surgically removed. However, he chose not to have a hysterectomy so he could still become pregnant.