Drinking sugary beverages in pregnancy linked to kids’ later weight gain

An expectant mom might want to think twice about quenching her thirst with soda.

The more sugary beverages a mom drank during mid-pregnancy, the heavier her kids were in elementary school compared with kids whose mothers consumed less of the drinks, a new study finds. At age 8, boys and girls weighed approximately 0.25 kilograms more — about half a pound — with each serving mom added per day while pregnant, researchers report online July 10 in Pediatrics.

“What happens in early development really has a long-term impact,” says Meghan Azad, an epidemiologist at the University of Manitoba in Canada, who was not involved in the study. A fetus’s metabolism develops in response to the surrounding environment, including the maternal diet, she says.

The new findings come out of a larger project that studies the impact of pregnant moms’ diets on their kids’ health. “We know that what mothers eat during pregnancy may affect their children’s health and later obesity,” says biostatistician Sheryl Rifas-Shiman of Harvard Medical School and Harvard Pilgrim Health Care Institute in Boston. “We decided to look at sugar-sweetened beverages as one of these factors.” Sugary drinks are associated with excessive weight gain and obesity in studies of adults and children.

Rifas-Shiman and colleagues included 1,078 mother-child pairs in the study. Moms filled out a questionnaire in the first and second trimesters of their pregnancy about what they were drinking — soda, fruit drinks, 100 percent fruit juice, diet soda or water — and how often. Soda and fruit drinks were considered sugar-sweetened beverages. A serving was defined as a can, glass or bottle of a beverage.

When the children of these moms were in elementary school, the researchers assessed the kids using several different measurements of obesity. They took kids’ height and weight to calculate body mass index and performed a scanning technique to determine total fat mass, among other methods.

Of the 1,078 kids in the study, 272, or 25 percent, were considered overweight or obese based on their BMI. Moms who drank at least two servings of sugar-sweetened beverages per day during the second trimester had children most likely to fall in this group. Other measurements of obesity were also highest for these kids. Children’s own sugary beverage drinking habits did not alter the results, the scientists say.

The research can’t say moms’ soda sips directly caused the weight gain in her kids. But based on this study and other work, limiting sugary drinks during pregnancy “is probably a good idea,” Azad says. There’s no harm in avoiding them, “and it looks like there may be a benefit.” Her advice is to drink water instead.