TIS, I quit for both of my pregnancies, and then went right back to it. My OB/GYN smokes and, believe it or not, they actually had a smoking lounge on the maternity floor in those days. If he had someone in labor, he used to sneak out for a break, and come knocking on my door to go join him for a smoke. I can't believe that I went about 8 months, and didn't even make it out of the hospital without starting up again (and I don't blame my doctor. It would've happened with or without him).