The last time I checked our rules for interviewing an applicant for a position, it was an absolute no-go to ask them about whether they are going to take a maternity leave or not...
This is what I thought to according to my uncle...but I wouldn't be surprised if they did a test case of "pretend" interviews and asked for employer input afterwards.
Also, I totally think it should be asked. It's a big problem when the employer and employee aren't on the same wavelength about that both the medical and family leave portion