Any amount of cigeratte smoke affects your baby. It makes the birth weight lower and it also effects the umbilical cord (the way the baby gets nutrition and oxygen from you). I have seen baby's from mothers who smoke 2 packs a day and some from mothers who only smoke a pack a week, the mothers who smoke more give more effect to thier babies, where the mothers who smoked less had less effect. I know there are effects (from working in the Neonatal ICU) on your baby and I would stop for the health of your baby. I am a current smoker and from the babies that I have seen from mom's who smoke I would NEVER keep smoking if I was to become pregnant!!!!!!