I work in the public sector in an area staffed almost entirely by women. In this financial year we have had 4 women (from a staff of 24) go on maternity leave, meaning for a large part on the year we have been paying double salaries for those roles, while cover was employed.
This has meant that our department has gone into deficit and that we will be put on special measures for our financial audit for the next 3 years. A right pain in the neck and I seriously think that my boss would think twice about employing so many women if she had a choice. If we were a private company we would have gone bust.
In other industries, where there is more competition for jobs from men, it must be easy to find a "reason" to employ the man rather than a woman of child bearing age. I'd like to think I'd be professional and fair,but if I were in that position and faced with a choice between 2 equally qualified candidates I'd probably choose the man. (I know there are reasons a man can need extended leave, but in practice it is usually women)