How do you comfort a friend who had a miscarriage?

I feel that there is no way to talk to someone who had gone through a miscarriage. Like Hui Qun mentioned, it's best to simply be there. When I had my etopic, my closest friends never once brought that topic up but were constantly by my side. If I gone too quiet, they would text me or call my ex-husband just to check if I'm doing okay. They may feel that it's nothing much but I am very grateful to them until today.