anotherfoirequester I would go back to the trust with more questions:
We assign a sex to that child based on the appearance of their genitals. Much follows from that, including our expectations of the child's future behaviour and life.
Why are they accepting that there should be any expectations?
However, anatomy is not always a good guide to what gender a child will be, or even what sex they are
They seem to be confusing being trans and having a disorder of sexual development. Why is anybody assuming a gender? What is a gender?
They also seem to be implying that people are regularly observed to be the wrong sex because of their genitals, which would only happen in a very few instances where somebody has a specific disorder of sexual development. This is why we don't rush girls to A&E when they have their first period.
When western science first considered sex and gender it was assumed that there were only two types of humans: men who were masculine and attracted to women ; and women who were feminine and attracted to men
This seems to be a misreading of history. The concept of 'gender' is recent and is a cultural, not medical concept. If the hospital trust thinks that humans can reproduce using a third gamete, or that there a humans who produce both gametes, please could they explain.
We understand that some people are born intersex
What do they understand by the term 'intersex'? Do they realise that many conditions included by 'Fausto-Sterling' as 'intersex' would not lead to any doubt about an individual's sex. For the few people whose sex is genuinely unclear, why is it more helpful to have gender expectations? Why is it not better to simply value individual humans?
We say that these people have a gender identity that is different to that they were assigned at birth
Why is anybody assigning an identity to a baby???