Several decades into the 21st Century, it is unlikely that the interviewer doesn't know that this question is a no-no. It is a violation of Title VII of the 1964 Civil Rights Act to discriminate against a woman on the basis of pregnancy or childbirth. As the interviewee, you have three choices: 1) Tell the interviewer that you believe he or she is violating the law and walk out; 2) Finesse the answer to the question without creating open conflict; 3) Answer the question honestly and move on. It's your choice, but diplomacy shows intelligence and maturity. It could be a good choice if the company has a generally solid reputation on equal employment opportunity issues. Read up on what company representatives are and are not allowed to ask in pre-employment interviews. Decide beforehand how you will handle a question like this.