Two mothers in the United States were able to carry the same baby in what's believed to be a fertility treatment first.
Married couple Ashleigh Coulter, 28, and Bliss Coulter, 36, knew they needed a sperm donor in order to have a biological child.
But both women also wanted to be involved in the in-vitro fertilisation process.
Thanks to a new type of IVF, the couple got their wish.
The couple are now the first to have successfully undergone "reciprocal effortless IVF", with their much longed-for son Stetson Lane born on June 6.
Having achieved what they previously thought was impossible, the pair credit their fertility specialists Dr Kathy Doody and husband, Dr Kevin Doody, of CARE Fertility in Bedford, who were first in the world to attempt the process.
It began just like a conventional IVF procedure; the stimulation of Bliss' ovaries, followed by the harvesting of eggs. Here's where things start to go down a different path.
In traditional IVF, the eggs and sperm are placed in incubators in a laboratory to fertilise. In the case of the Coulters, they were placed into chamber of the INVOcell device immediately after egg retrieval, then transferred to Bliss where the embryos incubated for five days.
After the device was removed, the resulting embryos were frozen.
USA Today clarified why incubation by Bliss, was just as effective as the lab.
"Because embryos don't have livers, kidneys or lungs, traditionally, electromechanical devices like incubators are used in labs to remove toxins and try to maintain a supportive environment for the embryo."
Because Bliss has a liver, kidneys and lungs, her body performs the same function just as effectively, and in a natural environment.
It was plain sailing from there with Ashleigh conceiving first go, after a medical evaluation and doses of estrogen and progesterone, followed by embryo transfer.
"She got to carry him for five days and was a big part of the fertilisation, and then I carried him for nine months," Ashleigh told USA Today. "So that made it really special for the both of us – that we were both involved. She got to be a part of it, and I got to be a part of it."
Bliss added, "No one really knew it was possible, but it worked magnificently."
Bypassing the lab element - which is called reciprocal IVF - from the process also cut costs by half. In the US, traditional reciprocal IVF costs between US$15,000 and $20,000. For reciprocal effortless IVF, the Coulters paid $8000.
They also have another two embryos on ice, should they decide they'd like for Bliss to be the biological mother for any future siblings.
A second same sex couple has since had success with the same specialists and procedure, giving birth to a baby daughter in September.