A wise Catholic prince is married to a woman of the same class, or for certain physical traits with a hope of passing them to their progeny, is an form of "eugenics."
A man and woman who are certain to produce mutilated children are allowed to forego children altogether provided their will is upright. This is what was meant by a "eugenic indication."
Then there are evil forms of "eugenics" like advocated by the wicked M. Sanger.
You just don't like the word because it now has bad connotations.