Babies' Stress Levels Remain High Even as They Fall Asleep

Just because your baby stopped crying, it doesn’t mean that he is all better--at least, according to a study published in the journal Early Human Development. Apparently, even after crying himself to sleep, your baby’s stress levels remain high. 

Researchers studied 4- to 10-month-old babies who had trouble settling down without being comforted. As part of the experiment, they were put to bed but left to cry themselves to sleep. For three days, their mothers stayed in a nearby room where they could hear their kids but were not allowed to go to them. To check for any changes, levels of cortisol (otherwise known as the stress hormone) in both mothers and babies were measured on the first and third night. 

Based on the results, both mothers and babies had high levels of cortisol on the first night. On the third night, however, a change was logged. Babies had started dropping off to sleep faster, causing their mothers’ cortisol levels to drop as well. Unfortunately, the same could not be said for the stress levels of the infants. While their crying eased off more quickly, their stress hormones remained high even as they slept. "Although the infants exhibited no behavioral cue that they were experiencing distress at the transition to sleep, they continued to experience high levels of physiological distress, as reflected in their cortisol scores," says Wendy Middlemiss, a researcher at University of North Texas.

However revealing the study is, there are still many advocates of controlled crying. Some mothers believe that babies should be trained to sleep on their own. Still, these findings may have you rethinking your parenting style, or at least taking some steps to help your baby sleep better at night.

(Photo by ssstok via Flickr Creative Commons)