well im guessing dh had something to do with the choice? he needs a kick up the backside, go on strike.
it can be lack of room because the baby is using it all, it can be the fact that you are carrying a baby so your body is working hard and it can be anaemia, i get breathless when i need iron (pregnant or not).
at your dh. Tell him to strap a sack of potatoes to his stomach and see how well he manages. I'm with you though, you definitely lose 'precious vessel' status when you get to no3 and beyond. Sometimes before that as my friend knows from being made to move house on her own at 8 months pregnant with no2 (dh apparently had no leave left to take - conveniently he had used it all beforehand) Anyway I seem not to be answering your question so will leave <shuts door quietly>