November 19, 2007 (Oakland, CA) - Mothers who reported sleeping five hours or less per day when their babies were six months old had a threefold higher risk for substantial weight retention (11 pounds or more) at their baby's first birthday than moms who slept seven hours per day, according to a new study by Kaiser Permanente and Harvard Medical School / Harvard Pilgrim Health Care.
The study, published in the November issue of the American Journal of Epidemiology, is the first to look at the impact of sleep deprivation on postpartum weight retention. Previous studies have looked at the effect of early postpartum sleep deprivation on mothers' cognitive and emotional health but never associated weight gain.
"We've known for some time that sleep deprivation is associated with weight gain and obesity in the general population, but this study shows that getting enough sleep - even just two hours more - may be as important as a healthy diet and exercise for new mothers to return to their pre-pregnancy weight," said Erica P. Gunderson, PhD, an investigator at the Kaiser Permanente Division of Research in Oakland and the lead author of the study.
The study also found that mothers who slept fewer hours at one year postpartum than they did at six months postpartum had twice the risk of substantial weight retention. Other studies have shown that persistent sleep deprivation causes hormonal changes that may stimulate appetite. Shorter sleep duration has not only been linked to obesity in women, but coronary artery disease and diabetes as well.
"With the results of this study, new mothers must be wondering, 'How can I get more sleep for both me and my baby?' Our team is working on new studies to answer this important question," said Matthew W. Gillman, MD, SM, Department of Ambulatory Care and Prevention, Harvard Medical School/Harvard Pilgrim Health Care.
The study looked at 940 women participating in Harvard's Project Viva, an observational, longitudinal cohort study of prenatal and postnatal health. The women, whose median age was 33 years old and were a mix of Caucasian, African American and Hispanic, were queried about their sleep habits and weight at the six-month and one-year postpartum assessments. Forty-seven percent of the women were first-time mothers, 37 percent had two children, and 16 percent had three or more children.
"A new baby's first year at home is a hard adjustment for everyone. That's why Kaiser Permanente has integrated our care for moms with our care for babies. We give moms tools and services to make it easier to juggle everything, and get back into shape: a pregnancy e-newsletter, newborn clubs, online health encyclopedia, online programs, podcasts, videos, weight and exercise programs, and discounts for gym memberships and Weight Watchers enrollment," said Tracy Flanagan, MD, Director of Women's Health, Kaiser Permanente Northern California. "But the best advice of all for moms with new babies is ask for help, get support and take care of yourself."
The study was funded by the National Institutes of Health, Harvard Medical School and Harvard Pilgrim Health Care Foundation.
About Kaiser Permanente Division of Research
The Kaiser Permanente Division of Research conducts, publishes, and disseminates epidemiologic and health services research to improve the health and medical care of Kaiser Permanente members and the society at large. It seeks to understand the determinants of illness and well being and to improve the quality and cost-effectiveness of health care. Currently, the center's 400-plus staff is working on more than 250 epidemiological and health services research projects.
About Kaiser Permanente
Kaiser Permanente is America's leading integrated health plan. Founded in 1945, it is a not-for-profit; group practice prepayment program headquartered in Oakland, Calif. Kaiser Permanente serves the health care needs of more than 8.7 million members in nine states and the District of Columbia. Today it encompasses the not-for-profit Kaiser Foundation Health Plan, Inc., Kaiser Foundation Hospitals and their subsidiaries, and the for-profit Permanente Medical Groups. Nationwide, Kaiser Permanente includes approximately 156,000 technical, administrative and clerical employees and caregivers, and more than 13, 000 physicians representing all specialties. For more Kaiser Permanente news, visit the KP News Center at: http://xnet.
Harvard Medical School
Harvard Medical School (www.hms.harvard.edu) has more than 5,000 full-time faculty working in eight academic departments based at the School's Boston quadrangle or in one of 47 academic departments at 18 Harvard teaching hospitals and research institutes. Those Harvard hospitals and research institutions include Beth Israel Deaconess Medical Center, Brigham and Women's Hospital, Cambridge Hospital, The CBR Institute for Biomedical Research, Children's Hospital Boston, Dana-Farber Cancer Institute, Forsyth Institute, Harvard Pilgrim Health Care, Joslin Diabetes Center, Judge Baker Children's Center, Massachusetts Eye and Ear Infirmary, Massachusetts General Hospital, Massachusetts Mental Health Center, McLean Hospital, Mount Auburn Hospital, Schepens Eye Research Institute, Spaulding Rehabilitation Hospital, VA Boston Healthcare System.