Children are created by God and EACH ONE is created the way they are for a reason. He knows what He is doing and there is a purpose for all of His creation.
I had a cousin born with severe birth defects 27 years ago. He survived less than four days and his mother held him in her arms as he died. My aunt and uncle have said that they wouldn’t trade those few hours for anything in the world.
And the baby would have suffered death either way; at least he died feeling the love from his parents.
Everyone born has to die anyway. Is that a reason to murder them?