Smoking during pregnancy alters newborn stress hormones and DNA

http://www.eurekalert.org/pub_releases/2014-10/l-mhs101714.php

PUBLIC RELEASE DATE: 17-Oct-2014

Contact: Elena Falcone-Relvas
Lifespan

Miriam Hospital study finds smoking during pregnancy alters newborn stress hormones and DNA

PROVIDENCE, R.I. – Researchers from The Miriam Hospital have studied the effects of smoking during pregnancy and its impact on the stress response in newborn babies. Their research indicates that newborns of mothers who smoke cigarettes during pregnancy show lower levels of stress hormones, lowered stress response, and alterations in DNA for a gene that regulates passage of stress hormones from mother to fetus. The study and its findings have been published in the journal Psychoneuroendocrinology.

"Our results suggest that these newborns may not be mounting adequate hormonal response to daily stressors. Their stress systems may not be prepared for the stressors of daily life," says lead researcher Laura Stroud, Ph.D., of the Centers for Behavioral and Preventive Medicine at The Miriam Hospital. "This may be particularly detrimental in babies born to mothers who lack resources and parenting skills and whose babies may encounter more daily stressors."

National health statistics show that despite the warnings and known health risks, approximately one in 10 expectant moms in the United States continue to smoke during pregnancy, with higher rates among young, poor, and underserved moms. Babies born to smoking mothers are born smaller, are more likely to be premature, and are at greater risk for medical complications. Smoking during pregnancy is also associated with long-term behavioral and health problems in child and adult offspring, including asthma, behavior and attention problems, and nicotine addiction. However, biological mechanisms underlying short and long-term effects of smoking during pregnancy on offspring are not well understood.

"One possibility is alterations in stress hormones and epigenetic changes (chemical modifications) in DNA" Stroud says. "We were interested in stress hormones because alterations in stress hormones have been linked to both smoking and behavior problems and because maternal stress hormones during pregnancy exert potent long-term effects on offspring. In particular, we sought to investigate effects of smoking during pregnancy on the newborn stress hormone cortisol." Cortisol is part of the hypothalamic pituitary adrenocortical system that works synergistically with the "fight flight" stress system.

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