Sleep fragmentation tires new moms

SEATTLE, June 10 (UPI) -- U.S. researchers say sleep fragmentation -- rather than lack of sleep -- causes new mothers' fatigue.

Study leader Megan Clegg-Kraynok and Hawley Montgomery-Downs of West Virginia University in Morgantown, W.Va., supports the hypothesis "new moms' fatigue" is due to the interrupted nature of their sleep rather than the timing or amount of sleep.

"We found that although our participants are quite fatigued, and their sleep at night is highly interrupted, first-time mothers of newborns go to sleep at night and awaken in the morning at the times they report are their preferred sleep and wake times," Clegg-Kraynok said in a statement.

"Mothers of newborns who have other children also fell asleep at their preferred time, but awoke for the day earlier than their preferred time. We expect this is because they are awakened by the older child."

The study involved 24 women with an average age of 30.5 years and average yearly income of $65,808. Of the participants, 92 percent were white, 96 percent were married/cohabitating, 50 percent were first-time mothers and 67 percent were breastfeeding. Except for mothers with multiple children, sleep/wake times remained aligned with self-reported preferred sleep/wake times.

The findings were presented at Sleep, the annual meeting of the Associated Professional Sleep Societies in Seattle.