Tammy Lobel’s hormones are being blocked by an implant on the inside of the 11-year-old’s upper left arm, which must be replaced once a year.

Ms Moreno explained: ‘In other words, she will stay as a pre-pubescent boy until she decides and we feel that she can make this decision about surgery.’

His parents say the hormone treatment will give him time to figure out if he wants to fully transition to being female or go through puberty as a boy.

By age 14 or 15 the device will need to be removed so that Tammy can go through puberty, Ms Moreno said.

If he chooses to stop taking the drugs, he will undergo natural male puberty at a later stage and his future fertility would not be impacted.

Should their son decide to transition to an adult female, he can take female hormones as well, which would raise his voice, allow him to grow breasts and develop other feminine physical characteristics.

The young boy is an adopted son of a lesbian couple, the couple says that he was not pressured into making the change.