People can't be "born" transgender. There isn't a transgender gene, and there is no test to determine transgenderism at birth.
"Gender refers to the characteristics of women, men, girls and boys that are socially constructed. This includes norms, behaviours and roles associated with being a woman, man, girl or boy, as well as relationships with each other. As a social construct, gender varies from society to society and can change over time."
https://www.who.int/health-topics/gender#tab=tab_1
It is not possible to be born identifying as "socially constructed characteristics." It is impossible to be born identifying as "norms, behaviours, and roles associated with being a woman/man/girl/boy, which can vary by society and change over time." One can only identify with a social construct by learning/experiencing the social construct.
How can a baby have an identity which is socially constructed?