Smoking during pregnancy may lead to asthma in grandchildren, study says

• The effects of smoking may travel through the generations, not just the umbilical cord.
• New research suggests that a young child whose grandmother smoked while pregnant may have double the risk of developing childhood asthma, compared to a child whose grandmother didn't smoke during this critical period.
• The number of people in the United States with asthma has more than doubled in the last 20 years, most notably among preschool children, making the disease a significant public health burden, the researchers said.
• For the new study, the researchers conducted interviews with parents or guardians of 908 children, 338 of whom had had asthma during their first five years of life and 570 of whom did not have asthma.
• Children whose mothers had smoked while pregnant were 1.5 times as likely to develop asthma early in life, compared to children whose mothers did not smoke.
• If the child is female and her eggs are damaged, that could affect her future children.
• Also, any damage to the fetus's mitochondria, a critical component of cell function, could be passed down through the maternal line.
• In either case, the DNA damage may put children and grandchildren at risk for asthma by compromising their immune function, the researchers said.
• In fact, earlier research unrelated to this study had shown that women who smoke during pregnancy could be causing chromosomal abnormalities in fetal cells that may increase risks for both childhood and adult leukemia.
• "Maybe we could use this as part of a child's history, one more thing to stack up to make a determination of whether the child will develop asthma based on family history."
• A separate study, this one appearing in the May 15 issue of Cancer, found that smokers who received one or more abnormal results using spiral chest computed tomography screening were more likely to quit.