It can. It just depends on if you're in a room with them an the room gets all clouded out. It wouldn't show as much as it would if you were smoking but it'd still show up a lil bit.. I smoked in the very beginning of my pregnancy, it was only a couple times. Before I was pregnant I smoked everyday all day so it stayed in my system for a while. It was still in my system over a month later! My doc said it wasn't showing up that much in my system anymore but it was still there, so she asked if I had been around anyone that was smoking.
It can't show up in a drug test but it can effect you.
It can just like with cigarettes.