Firstly, in my first pregnancy from when I first felt the baby move, I never let it sleep. If it was quiet for more than an hour, there I'd be, prodding away to wake it up. I now wonder if that was why he turned out to be a poor sleeper. (THIS bump is prod-free.)
Secondly - and my thanks to FrazzledFairy for this theory - I slept really badly in my first pregnancy, and produced a poor sleeper. FF slept well and produced a good one.
We are both sleeping badly this time around...
Can anybody corroborate or otherwise either of these theories?