Pregnant women who smoke run into the risk of their children have reading problems later in life,

study has found.


The reserachers looked at the reading tests of 5,000 students and found that many whose mothers smoked while pregnant struggled on reading comprehension and other tests.

The findings are published in

Lead author

a Yale professor of pediatrics, and his colleagues compared performance on seven specific tasks – reading speed, single-word identification, spelling, accuracy, real and non-word reading, and reading comprehension.

They adjusted for socioeconomic status, mother-child interactions and 14 other potential factors.

They found that on average, children exposed to high levels of nicotine

in utero

scored 21 percent lower in these areas than classmates born to non-smoking mothers. The children were tested at age seven and again at age nine.

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,” Gruen said in a statement.