Both my kids came two weeks late. I was happy for the distraction of work in those four long weeks. I was less inclined to work after the kids were born.
The thing about childbirth is that once it's on, it's on. Until then, you just have to get on with things or you can very easily go mad. And that's just the blokes!
If the baby is not born before kick-off, give the kid right up to the last minute to rule himself out of the game.
The worst thing that could happen is that he laces up the boots and his partner goes into labour an hour before kick-off, when the team can't be changed... But even then, it would have to be an extremely quick labour in order for Rob to miss out on it altogether ... and you would expect that she would be showing signs of pre-labour if that were likely to happen.
Then again, you just can't predict this stuff...