It's well known that smoking while pregnant can have detrimental effects on a baby's physical development. Now comes new research showing that babies born to mothers who smoked more than a pack a day while pregnant later scored significantly lower on reading tests than kids who weren't exposed to prenatal smoking.
Researchers from the Yale School of Medicine analyzed data from more than 5,000 kids who were part of a 1990-1992 longitudinal study in the United Kingdom involving more than 15,000 children. They compared the children's performance on seven specific tasks—reading speed, single-word identification, spelling, accuracy, reading real and nonwords, and reading comprehension—with how much their mothers smoked while pregnant. The kids were tested on the reading skills at ages 7 and 9, according to a Yale University news release.
Researchers found that "on average, children exposed to high levels of nicotine in utero—defined as the minimum amount in one pack of cigarettes per day—scored 21 percent lower in these areas than classmates born to nonsmoking mothers," the university says.
And the release adds this: "Among students who share similar backgrounds and education, a child of a smoking mother will, on average, be ranked seven places lower in a class of 31 in reading accuracy and comprehension ability."
"It's not a little difference—it's a big difference in accuracy and comprehension at a critical time when children are being assessed, and are getting a sense of what it means to be successful," said Dr. Jeffrey Gruen, the study's lead author and a professor of pediatrics and genetics at the Yale School of Medicine. He also noted that the effects of prenatal smoking are "especially pronounced" in kids with speech problems.
The study was published this month in The Journal of Pediatrics.