Despite a decline over the past decade in the number of women who smoke during pregnancy, smoking is still a major cause of newborn deaths, early births and babies born with low birth weight.
"We know about half of women quit when they find out that they are pregnant, but a lot of women are still smoking during pregnancy," said Patricia Dietz, DrPh, lead study investigator.
The study appears online and in the July issue of the American Journal of Preventive Medicine.
Dietz and co-investigators examined data from the US Linked Birth/Infant Death Data Set, which included all 3.3 million births of single babies that occurred in the United States (with the exception of California) during 2002. About 11.5% of babies, or 386 000, had mothers who smoked during pregnancy.
Researchers determined that prenatal smoking caused 5% to 8% of premature births and 13% to 19% of cases of low birth weight in babies carried to full term. Of infants who died, 5% to 7% of preterm-related deaths and 23% to 34% of deaths caused by sudden infant death syndrome (SIDS) might have been preventable if the mother had not smoked before pregnancy.
In addition, the researchers wrote that if all women quit smoking during pregnancy, it could cut health care costs by about US$232 million (about R1.8 billion) every year - and improve overall health for both mothers and children.
"The percentage of SIDS deaths that might be avoided with smoking cessation is a significant number," said Diane Ashton, M.D., deputy medical director of the March of Dimes. "For women who smoke and are considering pregnancy, we strongly recommend that they get preconception counselling for smoking cessation."
Given these sobering statistics, why do some women continue to smoke during pregnancy?
"Studies have shown that these women may be dealing with a lot of stress, such as economic hardship, or they might be dealing with depression or other mental health issues," Dietz said. "Most of them are living with other smokers that make it difficult to quit. They may be living in communities where it's acceptable to smoke - where everyone is smoking. So it's really complex."
"This is an addiction," Ashton said. "If pregnancy could cure addiction then none of these issues would be a problem. During pregnancy, women tend to be a little more highly motivated to address their addictions, but a lot of it depends on the level of readiness of the individual."
Source: American Journal of Preventive Medicine
