First study to examine the probability of obesity in preschoolers according to their mother’s weight early in her pregnancy

Maternal obesity in early pregnancy more than doubles a child’s risk of obesity at 2 to 4 years of age, according to an article by a researcher at Mathematica Policy Research, Inc., published in the July issue of Pediatrics.

The findings, which shed light on the risk factors for developing obesity, suggest that prevention strategies should begin at, or even before, birth.

Although previous research has shown that obesity runs in families, this is the first study to examine the probability of obesity in preschoolers according to their mother’s weight early in her pregnancy. Twenty-four percent of children in the study whose mothers were obese during the first trimester of pregnancy were obese by age 4, compared with nine percent of those whose mothers were of normal weight during the first trimester. Looked at another way, obesity occurred in almost 1 in 4 of the children born to obese mothers, compared to fewer than 1 in 10 of those born to mothers of normal weight. Previous research has shown that many obese preschoolers continue to have weight problems in adolescence and beyond.

“Although there are twice as many obese children now as 20 years ago, we know little about how to stop this alarming trend,” notes author Robert C. Whitaker, M.D., a senior fellow at Mathematica. “The periods before a mother conceives, during her pregnancy, and in the early years of her child’s life may provide important prevention opportunities that have not been fully explored.”

The study suggests that preschoolers’ obesity was associated with other factors easily assessed at birth, including high birthweight, being first born, and having a mother who smoked in pregnancy, further underscoring the importance of prevention efforts very early in life.

“By the time a child reaches school age, many of the behaviors that lead to obesity are well established. Moreover, by that time environmental influences outside the home are playing a larger role in shaping a child’s behavior,” Whitaker says.

The study, funded by the Economic Research Service of the U.S. Department of Agriculture, collected data on nearly 8,500 low-income children enrolled in Ohio’s WIC (Special Supplemental Nutrition Program for Women, Infants, and Children) program. WIC height and weight data were linked to birth certificate records. The children were followed from the first trimester of gestation until 24 to 59 months of age. WIC, which reaches half of all U.S. children during infancy and is actively developing strategies to prevent childhood obesity, now permits income-eligible children to be certified for WIC if they are born to mothers who are obese in pregnancy.

For an interview with the study author or a copy of the article, “Predicting Preschooler Obesity at Birth: The Role of Maternal Obesity in Early Pregnancy,” contact Joanne Pfleiderer, 609-275-2372, [email protected].

Pediatrics, a peer-reviewed journal published by the American Academy of Pediatrics, has the largest circulation of any pediatric journal in the world.

Mathematica, a nonpartisan firm, conducts policy research and surveys for federal and state governments, as well as private clients. The employee-owned company, with offices in Princeton, N.J., Washington, D.C., and Cambridge, Mass., has conducted some of the most important studies of nutrition, welfare, health care, education, employment, and early childhood policies and programs in the United States. Mathematica strives to improve public well-being by bringing the highest standards of quality, objectivity, and excellence to bear on the provision of information collection and analysis to its clients.