stress

is debilitating. Pregnant women should stay away from it or learn how to manage it.

Things that can trigger it are numerous. But all of them can be dealt with through discussion, understanding, sleep and breathing techniques.

Discussion and understanding are those things that are easily supplied by your loved ones.
Sleep is self explanatory - don't really want to get too much of it, but you still need at least 8 hours or so.
Breathing techniques on the other hand can be obtained here.