Achievement Unlocked: Midnight Snack
This morning while waking up, Christina told me that she'd unlocked a Pregnancy Achievement: she was woken at 0300 by hunger so severe that she couldn't fall asleep again. She then went downstairs, ate half a slice of sandwich bread, and then came back to bed feeling stuffed.
All I can say to this is that the hunger mechanism of a pregnant woman is a very finely calibrated system.