My employer doesn't have a maternity policy. Actually, they do but they don't seem to have one written down so it's just down to the individual to try and work it out for themselves. Basically we've got a really useless HR dept. When I told the (old, male) HR manager that I was pregnant he actually looked quite terrified. He obviously didn't have a clue what to do and I had to tell him about the new legislation because he didn't know anything about it.
We're trying to get them to put some procedures and policies in place. If anyone's got a really good maternity/flexible working policy at their work I'd love to see it.