Don’t ask your colleague if she’s pregnant (again) or when she’s going to have (more) kids.
Definitely never ask her while you’re passing one another in the hallway in front of a half-dozen colleagues.
You probably mean well and have no idea.
She knows this. That’s why she’s been really nice about it when others asked.
But what you might not realize is that she is thisclose to responding with, “I’ve miscarried twice in the last 18 months. If you could share that with the other nosy fuckers we work with, I would appreciate it.”
It’s 2015. If your colleague wants you to know her fertility status, she’ll bring it up herself.