Link Between Smoking During Pregnancy, Autism

Women who smoke in pregnancy may be more likely to have a child with high-functioning autism, such as Asperger’s Disorder, according to preliminary findings from a study by researchers involved in the U.S. autism surveillance program of the Centers for Disease Control and Prevention.

"It has long been known that autism is an umbrella term for a wide range of disorders that impair social and communication skills,” says Amy Kalkbrenner, assistant professor in the University of Wisconsin-Milwaukee’s Joseph J. Zilber School of Public Health, lead author of the study. “What we are seeing is that some disorders on the autism spectrum, more than others, may be influenced by a factor such as whether a mother smokes during pregnancy.” The study was published April 25 online by the journal Environmental Health Perspectives. Smoking during pregnancy is still common in the U.S. despite its known harmful impacts on babies. Kalkbrenner found that 13 percent of mothers whose children were included in the study had smoked during pregnancy.

Kalkbrenner and colleagues’ population-based study compared smoking data from birth certificates of thousands of children from 11 states to a database of children diagnosed with autism maintained by the CDC’s Autism and Developmental Disabilities Monitoring Network (ADDMN). Of the 633,989 children, born in 1992, 1994, 1996 and 1998, 3,315 were identified as having an autism spectrum disorder at age 8.

“The study doesn’t say for certain that smoking is a risk factor for autism,” Kalkbrenner says. “But it does say that if there is an association, it’s between smoking and certain types of autism,” implicating the disorders on the autism spectrum that are less severe and allow children to function at a higher level. That connection, she adds, needs further study. April is Autism Awareness Month, and several studies of possible links between environmental factors and autism are being published by Environmental Health Perspectives at the same time as Kalkbrenner’s study. “The CDC recently released data indicating that 1 in 88 children has an autism spectrum disorder, making such environmental studies even more timely,” says Kalkbrenner.

Because autism involves a broad spectrum of conditions and the interplay of genetics and environment is so complex, no one study can explain all the causes of autism, she adds. “The goal of this work is to help provide a piece of the puzzle. And in this we were successful.”

Dieting During Pregnancy Increases Risk Of Obesity And Diabetes For Offspring

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If you're expecting, this might make you feel a little better about reaching for that pint of ice cream: New research published online in the FASEB Journal suggests that twins, and babies of mothers who diet around the time of conception and in early pregnancy, may have an increased risk of obesity and type 2 diabetes throughout their lives. This study provides exciting insights into how behavior can lead to epigenetic changes in offspring related to obesity and disease.

"This study may provide a new understanding of why twins can develop diabetes," said Anne White, Ph.D., study author from the Faculty of Life Sciences at the University of Manchester in Manchester, UK. "It also suggests that dieting around the time a baby is conceived may increase the chance of the child becoming obese later in life."

To make this discovery, White and colleagues conducted experiments involving sheep to investigate twin pregnancies and the effects of altering nutrition around the time of conception and early pregnancy. Specifically, scientists examined the brain tissue of fetal sheep before birth and found that there were changes in the genes that control food intake and glucose levels that may lead to obesity and diabetes. These findings are unique because the differences found in the genes are not inherited changes in the DNA sequence, but rather, epigenetic changes with alterations in the structure of the DNA and its associated proteins, histones, which affects the way that genes can behave in later life.

"This study shows that expecting mothers have to walk a really fine line when it comes to diet and nutrition," said Gerald Weissmann, M.D., Editor-in-Chief of the FASEB Journal. "It also shows that epigenetics is the 'new genetics': both our DNA and the histones in which it is wrapped are susceptible to binge eating and dieting - we are what our mothers ate."

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