According to the March of Dimes, other effects of smoking during pregnancy include placenta issues such as placenta previa and placenta abrupta, vaginal bleeding, and still-birth for the mother. For the fetus, effects include birth defects like cleft palate or cleft lip, premature birth, and low birth weight.
Smoking during pregnancy can also lead to low birth weight and/or to premature birth. These are serious problems because such babies are at much higher risk for problems like cerebral palsy and mental retardation. Smoking can also have harmful effects on a baby's lungs even while the baby is in utero.
Smoking increases the risk of ectopic pregnancy. Nicotine has a direct toxic action on tubal mobility. If smoking is stopped one month before conception, the risk becomes equal to the general population.
The relative risk of miscarriage in smoker women is 1.5 to 3, and it is depending on the dose. Thus, in women who smoke more than 20 cigarettes per day, the risk is of 20% compared to 10% for non-smoking women.