Cigarette smoking is not wise during pregnancy, nor for that matter at any other time in life. The smoke from even one cigarette may increase the speed of your baby’s heart as much as 25% above its previous rate. Tobacco smoke contains certain poisons such us nicotine. Theses fine their way into your bloodstream and effect the baby. If you are in the habit of smoking, it would be wise for you stop. If you have never started, don’t start now.