Here's the tipping point: five hours of shut-eye (for mother, not baby).
Moms who get at least that much sleep in a typical 24-hour period tend to shed more of their baby weight than other mothers, a new study shows.
That sleep time doesn't have to come all at once. A little sleep here, a quick nap there -- it all counts.
Data came from 940 women in Massachusetts who had healthy pregnancies.
Women who reported getting less than five hours of sleep when their babies were 6 months old tended to keep more of their pregnancy weight.
Those moms were three times as likely as mothers who slept seven hours to have retained at least 11 pounds of their pregnancy weight gain.
Erica Gunderson, PhD, and colleagues report that news in the American Journal of Epidemiology. Gunderson works at the Kaiser Permanente Research Foundation in Oakland, Calif.
So say researchers including the University of Minnesota's Pat McGovern, PhD, MPH.
They studied 661 Minnesota mothers of newborns.
The moms were 30 years old on average. Most were married or living with their partner.
The mothers were interviewed when their babies were 5 weeks old and 11 weeks old. Topics included the moms' physical health, mental health, and postpartum symptoms.
Fatigue was the moms' leading symptom, reported by nearly two-thirds of moms in the first interview and about 43% in the second interview, when about half of the moms had resumed working outside the home.
Moms who reported better physical health also said they were healthy and had supportive co-workers before pregnancy.
Also, the mothers rated their mental health more highly if they had been healthy -- with stable moods, supportive friends and family, control over their home and work, and manageable job stress -- before pregnancy.
Their findings appear in the Annals of Family Medicine.