I understand the reasoning but in 20 years I think we will have treatments.
Also, there are kids from perfectly healthy parents who get terrible diseases or even die. And there are kids with ill parents who are perfectly healthy.
I worry more about what type of society and climate we will leave behind, we are destroying this planet.
Finally, it might depend also on your outlook on life in general, whether you are religious or not and what you believe.
In general I sympathize with the idea that we wish to spare our kids our torments, but there is no guarantee in life. Life is neither fair nor safe