Totally confused article

[PrinceButthole]

Not quite sure where to start with this. Enjoy!

www.livestrong.com/article/231357-when-does-a-baby-develop-gender/

Why can't they just say "sex"
Your baby's SEX is determined at the very start... chromosomes.. blah blah.. SEX is observable...
Gender is the wrong word. It's so annoying.