by Pregnancy.org Staff
"Don't eat lunch meat!" "Exercise regularly." "Limit fish intake."... Advice for protecting your unborn baby leaps at you from all directions. No smoking is high on the list. Does stopping smoking really make a difference for you and your baby?
Definitely! Women who quit smoking before or early in pregnancy significantly reduce the risk for several adverse outcomes.
Compared with women who do not smoke:
Babies born to women who smoke during pregnancy:
Cigarette smoke contains more than 2,500 chemicals, with nicotine, tar, and carbon monoxide thought to be the most dangerous to the fetus. Recent research has linked maternal smoking and exporuse to second hand smoke with the following issues and concerns:
Smoking during pregnancy is a two-edged sword. It raises likelihood of a preterm baby and increases the likelihood the baby will have impaired respiratory function.
Babies born prematurely to women who smoked during their pregnancy may be at higher risk of sudden infant death syndrome (SIDS) than premature infants born to nonsmoking moms, new research from the University of Calgary suggests.
The Canadian study compares the breathing reflexes of "preemies" born to smokers versus nonsmokers. The researchers found that these tiny babies were more likely to have impaired recovery from pauses in breathing if their mother had smoked during her pregnancy.
"Our study shows that preterm infants make incomplete and/or delayed recovery from interruptions in breathing," study author and neonatologist Dr. Shabih Hasan, a professor of pediatrics at the University of Calgary, said in an American Thoracic Society news release. "This has clear implications for their risk of SIDS."
Smoking during the first trimester is associated with an increase in two common oral-facial birth defects, cleft lip and cleft palate. Study measured levels of a cotinine, a metabolite of nicotine, to determine if the mothers had smoked during pregnancy. Women who smoked were nearly 2.5 times more likely to have babies with oral clefts.
Babies whose mothers smoked 6-7 cigarettes or more a day were more jittery, more excitable, stiffer, and more difficult to console. The symptoms were similar to those found in newborns of women who use crack cocaine or heroin while pregnant. The data suggest “neonatal withdrawal” from nicotine, said the authors.
Even at 10 weeks of age, after the affects of nicotine would be quite reduced, babies exposed to maternal smoking were more irritable and difficult to sooth.
-- Babies whose moms smoked during pregnancy have smaller head sizes, measure shorter, and weigh less. Prenatal exposure to cigarette smoke retards fetal growth. Why?
"This study in one of the first to show a biochemical measurement of what is going on to cause the lower birth weight," said study author Malene Rohr Andersen, project manager of the Department of Clinical Biochemistry at Gentofte University Hospital. Analysis showed a 47% drop in levels of a protein, endothelial nitric oxide synthase (eNOS), that helps blood vessels to relax and blood flow to increase. These babies also experienced an 18% reduction in plasma levels of "good" HDL.