The health risks associated with smoking tobacco are widely publicized. Smoking during pregnancy can lead to additional risks and complications for both the pregnant woman and her unborn baby.
Some studies indicate that smoking can as much as double a woman's risk for having a low-birthweight baby. This occurs either due to the increased risk of preterm delivery or to poor fetal growth or both, caused by smoking. Low-birthweight babies are at risk of serious problems including cerebral palsy, mental retardation and learning problems. Smoking may lead to an increased risk of sudden infant death syndrome (SIDS) after birth.
Smoking may increase the risk of developing placental problems, such as placenta previa and placental abruption. It may lead to an increased risk of premature rupture of the membranes, which also leads to preterm delivery.
The more a pregnant woman smokes, the greater the risks for her pregnancy. Most of the studies referred to above assume that a woman smokes 3/4 of a pack of cigarettes a day. Cutting down or quitting smoking altogether can greatly reduce these risks. If a woman stops smoking during the first trimester, for example, the increased risk of having a low-birthweight baby all but disappears.