And nicotine is that addicting agent that causes the addiction and as a result, that woman becomes addicted. And that fetus can also become addicted to nicotine. On top of that, when an individual smokes, one other byproduct is carbon monoxide. And carbon monoxide is toxic to hemoglobin. Hemoglobin the carrier of oxygen. So once the woman inhales carbon monoxide, the carbon monoxide can bind to hemoglobin and decrease the Vinity of hemoglobin for oxygen.