"We’ve long known that a child’s sleep is vital to his or her growth, but the origins of problems affecting it remained unclear. Now, we have evidence that these patterns may be set early on, perhaps even before birth," Thomas O’Connor, Ph.D., associate professor of Psychiatry at the University of Rochester Medical Center and the study's lead author.
The survey-based study assessed more than 14,000 pregnant women. They responded to questionnaires that gauged how depressed or anxious they were. Later on, the women were then asked to report on their child’s sleep habits.
Surprisingly, babies born to mothers classified as anxious or depressed while pregnant dozed just as long as their unstressed-pregnancy counterparts – about 12 hours. However, they experienced more sleep problems. For instance, mothers classified as clinically anxious 18 weeks into pregnancy, compared to their non-anxious counterparts, were about 40 percent more likely to have an 18-month-old who refused to go to bed, woke early, and kept crawling out of bed. A similar effect was found in children born to mothers who were depressed during pregnancy.
These prenatal mood disturbances worked as reliable predictors of children’s sleep problems even when investigators controlled data for other factors already linked with poor sleep quality in children, including a mother’s level of postnatal anxiety or depression, her smoking habit, or her social class.
Related studies now show that stress, which is associated with increased exposure stress hormones, like cortisol, may disrupt a child’s formation of a bundle of nerve cells in the brain which act as a signalling system that tunes the body’s internal clock. This signalling system helps to properly regulate daily rhythms of waking, sleeping, even hunger – that is, if its formation has not been disrupted.
MEDICA.de; Source: University of Rochester Medical Center