Ethnicity question on mat forms

Hi. Just had the booking appointment for my second and experienced friction from the midwives about insisting on the correct ethnicity being listed for the mother on the documents. I'm mixed Aske-phardi and found it very odd that they basically wouldn't accept 'mixed-Jewish' despite Ashkenazi being more susceptible to certain genetic conditions - hence the need to have the ethnicity of the mother recorded accurately for the maternity notes. Has anyone else come up against this and did you find a work around? Any recommendations most welcome.