Mother's and Child's Weights Linked

A child’s weight may be influenced by the mother even before the child is actually born, according to a report in the medical journal Pediatrics.

The study shows that a child is more likely to be overweight at a very young age - at two or three years old - if the mother was overweight or obese before she became pregnant.

Information from the study also shows that other prenatal characteristics, particularly race, ethnicity, and maternal smoking during pregnancy, place a child at greater risk of becoming overweight.

Early Weight Linked to Life-Long Weight

Specifically, a child is at greater risk of becoming overweight if born to an African-American or Hispanic mother, or to a mother who smoked during her pregnancy, according to the study.

"There’s a good chance that an overweight child will stay overweight for the rest of his or her life," says study lead author Dr. Pamela Salsberry, an associate professor in the College of Nursing and School of Public Health at Ohio State University.

“A child who is overweight by her second birthday is more likely to be overweight at a later age,” says Dr. Salsberry. “Prevention of childhood obesity needs to begin before a woman becomes pregnant."

“Dr. Salsberry’s work underscores the importance of prenatal care and how the health habits of the mother prior to and during pregnancy may impact the health of her child through the early years of childhood and possibly through adulthood,” says Dr. Patricia A. Grady, director of the National Institute of Nursing Research.

“Understanding how these factors may contribute to obesity very early in life will better equip us to fight the increasing problem of obesity in America and help to prevent diseases associated with obesity, such as type 2 diabetes, heart disease, and some forms of cancer,” adds Dr. Grady.

The researchers analyzed the data for 3,022 children included in the National Longitudinal Survey of Youth's (NLSY) Child-Mother file. In this study, children were weighed at three age intervals - three, five, and seven years.

The survey also gathered information on each child's race and ethnicity as well as the mother’s pre-pregnancy weight.

Each mother was also asked if she had smoked while pregnant and if she had breast-fed her child.

Children were considered overweight if their body mass index (BMI) was greater than or equal to the 95th percentile for their age and gender. BMI is a calculation that takes into account both height and weight. A child in the 95th percentile for his or her weight is heavier than 95 percent of children at that age.

The study showed a significant relationship between a mother's weight prior to pregnancy and her child's weight. A mother's weight within one to two months before she became pregnant had the greatest impact on a child's weight at all three age intervals.

If a woman was overweight before she became pregnant, her child was nearly three times more likely to be overweight by age seven compared to a child whose mother was not overweight or obese, according to the study.

The risk that a child would be overweight at a young age increased with the degree of the mother's obesity.

The investigators report that at each age interval, about 4 percent to 6 percent more African-American and Hispanic children were overweight than white children.

However, the percentage of all children who were overweight, regardless of race or ethnicity, decreased with age.

"Some children lose extra body weight and become leaner as they grow," says Dr. Salsberry.

Lifestyle Factors an Influence

Children of mothers who smoked during pregnancy were more likely to be heavy at all three age intervals.

"Obviously smoking during pregnancy causes a host of serious problems, but this finding adds to the growing body of evidence that suggests that smoking during pregnancy may be a key risk factor that increases a child's chances of being overweight," says Dr. Salsberry.

Breast feeding had a slight effect on weight at each measurement: As much as 5 percent fewer children who were breast-fed were also overweight, compared to bottle-fed babies.

The researchers also looked at other factors that may affect a child's weight, such as the age of the mother when she gave birth, the child's gender, and whether or not the mother was married. None of these factors had the same degree of effect on childhood weight as a mother's weight prior to pregnancy, race, ethnicity, or smoking.

Two out of three children who were overweight at their final weighing were also overweight during at least one prior weighing. Three out of four children who were at a normal weight at the final weighing had always been at a normal weight.

"A child's weight at three years is a good prediction of what his weight will be at age five, and so on," notes Dr. Salsberry. "Weight states tend to persist over time. "Obesity continues to rise in adults. And that risk has increased in children, too. Interventions should begin immediately for children who are already overweight at these young ages."

Always consult your child's physician for more information.