Don't Sleep Much in Third Trimester? Your Baby May Be Fat, Later in Life

Something new to blame mothers for!  A new study has found that poor-quality sleep during the third trimester of pregnancy can increase the odds of weight gain and metabolic abnormalities in offspring once they reach adulthood, according to newswise.com.

By 24 weeks the sons of sleep-disturbed mothers weighed about 10 percent more than the sons of mice with uninterrupted sleep.

“Disrupted sleep is a common problem during the final trimester of a pregnancy,” the Web site quotes study director, sleep specialist David Gozal, MD, the Herbert T Abelson professor of pediatrics at the University of Chicago. “For some women, sleep fragmentation, especially sleep apnea, can be profound. We wanted to devise a system that enabled us to measure the potential impact of fragmented sleep on the fetus, which is uniquely susceptible so early in life.”

The researchers interrupted sleep for half of the mice in the study during days 15 through 19 of pregnancy, the mouse equivalent of the third trimester, newswise reports. "During the day, when mice normally sleep, a motorized brush swept through those cages every two minutes, forcing the mouse mothers-to-be to wake up briefly, step over the brush and go back to sleep. Pregnant mice in the other cages were not disturbed."

Newborns from both groups weighed the same at birth and initially had normal feeding habits and growth trajectories, but it was in adulthood where their paths grew apart.

“For several weeks after weaning all the mice seemed fine,” Gozal says. “But after 16 to 18 weeks — the mouse equivalent of early middle age — we noticed that the male mice born to moms with fragmented sleep were eating more. Their weights started creeping up.”

Scientists believe this happens because gene modifications in sleep-disturbed mice hold back a hormone that helps regulate several metabolic processes, including glucose regulation. Lower levels of this hormone correlate with increased body fat and reduced activity.

“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.”

As if this weren't bad enough, the mice with the gene modification also had health problems.  They scored poorly on glucose-tolerance tests. Insulin resistance is a hallmark of metabolic syndrome and type 2 diabetes.

They also had disproportionately high amounts of “bad fat,” as well as elevated levels of the bad cholesterol. Plus, their fat cells produced less of the hormone that regulates metabolism.

So, moms, try to get your sleep.  It's good for the baby, and for you, too.