Stillbirth, passive smoking linked
Sat, 30 Apr 2011 12:45:29 GMT
Chronic exposure to tobacco places expectant mothers at an increased risk of having a stillbirth or babies with low birth weight or small heads, a new study finds.
Women who live with smokers may have a slightly higher risk of stillbirth, a condition in which the baby dies during the third trimester of pregnancy, said the study published in the BJOG: An International Journal of Obstetrics and Gynecology.
According to the study conducted on about 12,000 Canadian women, 11 percent of these women were reportedly exposed to secondhand smoke.
The rate of stillbirth was 0.83 percent in pregnant women who passively breathe tobacco smoke; as for the to be mothers who were not secondhand smokers, however, the risk was as low as 0.37 percent.
The data also showed that after adjudting for other factors such as maternal age and drinking habits, secondhand smoke more than triples the odds.
Moreover, babies born to passive smokers weighed on average 54 grams less than those whose mothers lived and worked in smoke-free households.
The head circumference of infants whose mothers were exposed to cigarette fumes were also about 0.24 centimeters smaller than their peers whose moms were not exposed to tobacco-related chemicals before labor.
Researchers emphasized that their study does not consider smoke as the only suspect behind the findings, stressing that other unstudied risk factors might also be responsible for stillbirth in some women.
The most common causes of stillbirth worldwide are complications at the time of birth, infections during pregnancy, health conditions such as high blood pressure or diabetes, restricted fetal growth and birth defects.
However, "undiluted side-stream smoke contains many harmful chemicals and in greater concentration than cigarette smoke inhaled through a filter," warned Joan Crane of Eastern Health in St. John's and colleagues.
"This information is important for women, their families and healthcare providers," as secondhand smoke is thought to expose other people to about one percent of the smoke that active smokers inhale, researchers added.