The moment has passed, so I probably wouldn’t bring it up again just for the purpose of discussing the moral ramifications of sterilization. However, I guess if I were you I’d be prepared for “next time”-- whenever and whatever that may be-- if it seems appropriate to speak up.
www.omsoul.com and
www.hh76.com have great materials on contraception, abortion, and other moral issues of our time.
I tend to bring things up or make a comment only when I believe I can have an impact. Otherwise, I let them slide with my Protestant friends. For example, when my good friend (Baptist) makes a comment about someone getting saved, I don’t go into the theology of why that’s in error b/c I know that this will not change her beliefs and can damage our friendship.
There is no right or wrong answer to your question, it completely depends on the people involved and the situation.