Smoking in pregnancy tied to lower reading scores, study finds

Smoking in pregnancy tied to lower reading scores
Credit: Shutterstock

(Medical Xpress)—Yale School of Medicine researchers have found that children born to mothers who smoked more than one pack per day during pregnancy struggled on tests designed to measure how accurately a child reads aloud and comprehends what they read.

The findings are published in the current issue of The Journal of Pediatrics.

Lead author Dr. Jeffrey Gruen, professor of pediatrics and genetics at Yale School of Medicine, and colleagues analyzed data from more than 5,000 children involved in the Avon of Parents and Children (ALSPAC), a large-scale study of 15,211 children from 1990-1992 at the University of Bristol in the United Kingdom.

Gruen and his team from Yale and Brock University in Canada, compared performance on seven specific tasks – reading speed, single-word identification, spelling, accuracy, real and non-word reading, and reading comprehension – with maternal cigarette smoking, after adjusting for , mother-child interactions, and 14 other potential factors.

They 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 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," said Gruen, who also points out that the effects of smoking in pregnancy are especially pronounced in children with an underlying phonological (i.e., speech) deficit, suggesting an interaction between an (smoking) and a highly heritable trait (phonological ability).

"The interaction between nicotine exposure and phonology suggests a significant gene-by-environment interaction, making with an underlying phonological deficit particularly vulnerable," he said.

More information: doi:10.1016/j.jpeds.2012.09.041
www.jpeds.com/article/S0022-3476(12)01133-X/abstract

Related Stories

Maternal smoking causes changes in fetal DNA

May 18, 2011

Children whose mothers or grandmothers smoked during pregnancy are at increased risk of asthma in childhood, but the underlying causes of this are not well understood. Now a new study indicates changes in a process called ...

Recommended for you

Crankier babies may get more TV time

Apr 14, 2014

(HealthDay)—Fussy and demanding babies are likely to spend slightly more time plopped in front of a TV or computer screen when they're toddlers than are "easier" babies, new research finds.

User comments