SO agrees with aborting disabled children

I am 24 & I know people may disagree with me but I'm anti abortion. My parents tried for 10 years to have me, & finally got me through IVF & the thought of getting rid of a child makes me feel like I would be disrespecting them. 

Recently I was out with my SO & we were having a really good night until he said that when I get pregnant he wants to check if the baby has any disabilities & if it does "to get rid of it" I have never felt so much anger towards him! I have a brother who is disabled & I love him to bits. Yeah it was hard for parents & they had to give me more attention than me but he's the best brother ever & loves singing along to glee 😊 

Anyway I've tried talking to my SO about it but he just changes the subject, what should I do?