So, I know you're joking, but this is actually a Thing and I think it is far more reasonable than expecting that your friends will never go on a diet because it might hurt your feelings. Especially in western society, fertility or lack thereof is tied up in all kinds of sort of gross assumptions about one's value as a woman. Additionally, not being able to have kids is the sort of thing that can seriously alter one's planned life trajectory, even ruining the relationship that was supposed to produce said kids. It can become an all-consuming thing.
I do agree that the types who make infertility their identity and expect that no one else ever speak about having kids are unreasonable, but I don't think it's so bad to read the room before announcing a pregnancy.