Given that age prejudice is a very real, common and growing problem I don't feel at all bad about saying I'd prefer to hire women over 45.
I have't got children, however I worked for a large corporation and would have felt comfortable about taking mat leave if any of my pregnancies had stuck. At that time there was a 2-year qualifying period for SMP, so at least you would have got about 18 months' worth of good work before an employee went off to have kids.
If people are to be given the RIGHT to take up to year off work for personal reasons, with compensatory pay and a guaranteed return to work, then I feel it should be treated as a sabbatical with qualifying periods and flexible contigency in case they decide not to come back.
Small businesses can't afford to employ somebody who might not come to work for more than a few weeks. Big ones can. Having said that, I don't know any high-flying women who've taken their full entitlement. They take their jobs seriously and know the value of their input to their employers. Work-life balance is the thing, I believe.