It's an early form of the wanting to pick up the baby impulse.

Wrapping your arms around your belly to look warmly maternal and proud and enclosed works wonders.

You can sort of understand the impulse - let's face it, it's pretty damn cool - but it does sort of impart that "I am the package a baby comes in" feeling, which can be very disconcerting.

I didn't have too much trouble with it, but then I'm twice everyone else's size, which seems to make a difference.