Pregnancy smoking hurts reading ability

November 27, 2012 / Yale Daily News / — New research out of the Yale School of Medicine is the first to link prenatal nicotine exposure with impaired reading skills, the most recent finding in a large body of literature urging mothers not to smoke while pregnant.

Study authors analyzed more than 5,000 young children tracked through the Avon Longitudinal Study of Parents and Children (ALSPAC), a well-known database of children born in 1991 and 1992 in Bristol, England. After controlling for other factors that affect reading ability, such as socio-economic status and alcohol consumption, the researchers concluded that the more a mother smokes while pregnant, the more likely her child will struggle relative to peers on a broad range of reading tests, including comprehension, accuracy and speed. The paper first appeared online in The Journal of Pediatrics on Nov. 5.

The ALSPAC data includes genetic information about every one of its subjects, and Jeffrey Gruen, senior study author and professor of pediatrics and genetics at the Yale School of Medicine, said he initially engaged with the data set to elucidate the genetic underpinnings of dyslexia. The nicotine findings arose as his team identified possible factors that may underlie genetic effects of reading disorders. Gruen said he was “very surprised” to find that heavy maternal smoking of more than a pack a day could decrease reading performance by over 15 percent.