A transgender woman and her wife who stayed together while she transitioned have naturally conceived their first child.

Rebecca and Isabelle Sutherland first met as children and remained friends until they fell in love and married as husband and wife in 2016.

However, before the couple decided to commit to a family Isabelle had a secret she was afraid to reveal to Rebecca - that she was transgender.

Without knowing the reason, Rebecca was convinced her loving partner was ready to break off their marriage, ABC News reported.

She cornered Isabelle on their couch and told her she needed to open up about what was going on.

Young married couple Rebecca and Isabelle Sutherland had known each other since childhood before getting married and one transitioned from a man to a woman have welcomed their first child (pictured)

Much to her surprise Rebecca didn't react in a negative way but instead had her own confession, she had been hiding her bisexuality from her spouse.

'We just kind of broke down and I said, ''Look, I'm trans'', and Bec said, ''Oh, is that all?''' Isabelle said.

They weren't sure if they would start a family at that stage but Isabelle said she started to freeze some of her sperm before her transition was complete.

However the pair also decided to try and conceive before Isabelle got too deep into her transition cycle.

'Ultimately, we decided, 'You know what, we'll just give it a try for a couple of months to see how it goes before I start hormones,' she said.

The pair had known each other since childhood and were married in 2016 before each made their confession to the other

Within weeks of the decision Rebecca had fallen pregnant.

Then when Rebecca was in her second trimester Isabelle began her medical gender transition.

Their son Bailey would be born six weeks' premature and had to spend some time in an incubator before his parents could take him home.

They said on top of all the love and support their received after announcing Isabelle's transition they had also seen the best in people while taking Bailey out in public.

'People come up to us all the time [saying] 'oh, isn't he adorable' and have a chat about babies, and have a chat in general, and the fact that we're two mums almost never factors into it,' Isabelle said.