@Dtei Thank you :)
To be honest, there is just no good way.
There are 'less worse' ways (e.g. most people agree a message is better than in person).
But really, the person going through infertility is going through a type of trauma, and however they find out, it's going to be hard for them to deal with it and not to project their trauma. It requires a lot of emotional maturity and resilience. There are as many types of people going through infertility as there are people in the world, and some people will cope emotionally better than others.
Either way, the important thing to remember is that their reaction/ ability to cope is not the fault of the person who's announcing a pregnancy.
There is a responsibility on the person who's experiencing infertility as well - what do you expect your friends to do, particularly if you haven't given them any hint as to what you need? It's not reasonable to be angry at someone for being pregnant - you might feel that way, but it's simply a projection of your own trauma - you shouldn't express it.
I think empathy and understanding is needed on both sides of it but when someone is going through trauma, it can be hard to be reasonable.
As someone announcing a pregnancy you just have to remember that their trauma is not your fault or your responsibility, and there's nothing you can do to change it, and you are still entitled to enjoy announcing and celebrating your happy news.
I don't think you should minimise it as if it's no big deal when you announce it. It is a big deal and you're allowed to announce it properly!