"Did you have fertility treatments?"
With women in their 40s (and even 50s) giving birth and the number of multiple births on the rise, it's no wonder this question has become more common. Since people normally wouldn't dream of inquiring about your sex life (and asking how one conceived is virtually the same thing), it's likely that the question isn't being asked out of pure nosiness. It may be that your friend is struggling with fertility problems herself or knows someone who is. Regardless, though, how egg and sperm came to meet is truly nobody's business but your own.
Stop it by: Reminding the questioner of appropriate boundaries and saying, "That's really a personal question." No matter what remarks you hear, try to remember that people are genuinely happy and excited for you -- even if their choice of words doesn't always convey it.
Originally published in Parents magazine.