Because that's what I've been asked to complete a form on by my university where I'm studying. Surely a newborn can't identify as anything and hasn't grasped the concept of gender?
Email about this copied below:
Dear Student,
We are writing to you to ask you to complete a short online form (it will take less than two minutes to complete) to help us gather data we haven’t collected on your student record for our statutory return to the Higher Education Statistics Agency (HESA).
HESA requires us to collect this information (about sexual orientation and gender identity at birth) so that they can monitor equality and diversity in the higher education sector. We ask these questions of all students who sit within our HESA population. Normally we collect this during the online registration/re-registration process, but we have identified that you were not asked these questions at that time. HESA collect information on other equality and diversity indicators too, which you were asked when you registered/re-registered.