There are plusses and minuses to discussing a hypothetical maternity leave during job interviews, whether for residency, fellowship, or attending-level jobs.  On the plus side, you want to have this information in advance since it may be of importance to you in your future.  You can test the waters a bit in terms of the overall job appeal.  Since maternity leave is an employee benefit, just like health insurance, it should be clearly defined up front in the context of the employment process.  In that way, you can get a sense of the immediate financial impact of having a child so you can present yourself as a responsible planner.  Finally, sensitive issues such as this one may be easier to discuss hypothetically rather than in real time.  On the negative side, you do not want your potential employer to worry that you will start your job and promptly get pregnant (if you are not already).  Gender bias, defined as unfair differences in the treatment of men or women because of their sex, is a very real phenomenon.  For any employment, an appointment with human resources is prudent before accepting the position, especially if you are planning a family.