Children born to mothers, who experience poor sleep quality during the third trimester of pregnancy, are at a higher risk of gaining weight and developing metabolic abnormalities as adults.
Mother's lifestyle and habits, during pregnancy, have an impact on her offspring in many ways. A current study found that disturbed sleep during the third trimester of pregnancy increases the risk of weight problems and metabolic abnormalities in the offspring when they become adults.
"Disrupted sleep is a common problem during the final trimester of a pregnancy," said study director, sleep specialist David Gozal, MD., the Herbert T Abelson professor of pediatrics at the University of Chicago in a press statement. "For some women, sleep fragmentation, especially sleep apnea, can be profound. We wanted to devise a system that would enable us to measure the potential impact of fragmented sleep on the fetus, which is uniquely susceptible so early in life."
The study was conducted on a group of pregnant mice since using humans would extend the study duration to more than 50 years. The mice were divided into two groups. One group experienced disturbed sleep during the mice-equivalent third trimester, while the other group got adequate sleep.
Researchers noted that though newborns from both groups weighed the same at birth, their weight started diverting as they reached adulthood. Researchers also noted a few eating habits and growth trajectories in both groups of newborns as they reached adulthood, which were not present initially.
"For several weeks after weaning, all the mice seemed fine," Gozal said. "But, after 16 to 18 weeks -- the mice-equivalent of early middle age -- we noticed that the male mice born to mothers with fragmented sleep were eating more. Their weight started increasing."
The researchers focused more only on the male newborns because their hormone levels are easier to study. Researchers noted that the males born to mothers with disturbed sleep weighed about 10 percent more than the sons of those mothers with uninterrupted sleep.
"This is not huge obesity," Gozal said, "just 10 percent, a little extra at this stage. This would amount to 15 extra pounds in a human adult." A few of these mice, however, "became morbidly obese at 18 months of age or so," he said. "They died long before their unexposed counterparts."
Researchers said that this increased weight and metabolic abnormality risks were due to epigenetic modifications that reduce the levels of adiponectin, a hormone that helps regulate several metabolic processes, including glucose regulation.
"We found that the offspring of sleep-deprived mothers had largely inactivated AdipoQ, the adiponectin gene," Gozal said. "Such changes may affect other genes as well; we haven't studied all the potential targets yet. Even so, this is the first example of a perturbation during pregnancy that translates into a genetic risk, in midlife, for the next generation."
The study was published in the journal Diabetes.
