While it is already common knowledge that pregnant women should not drink alcohol while pregnant, new research suggests that drinking soda or pop could also cause health problems for the child later in life.

The study conducted through Harvard Medical School found that expectant mothers who drink an average of two sugary drinks a day are 63 percent more likely to have kids diagnosed with asthma when they are 7 to 9 years old.

“Increasingly we’re understanding that the processes that put a kid on a trajectory for obesity and asthma start in pregnancy,” Rosalind Wright with Icahn School of Medicine told Medline Plus. “This may give us some clues to how early life programming of asthma starts in utero, and how we might intervene more directly to give children a healthy start.”

The researchers said the correlation may be due to fructose’s potentially inflammatory effect on the child’s lungs.

However, the research team also looked at the effects of fruit juice because it contains naturally occurring fructose.

“We don’t see evidence for the same strength of adverse effects from fruit juice,” Harvard nutrition professor Emily Oken told Medline Plus. “That may be perhaps because fruit juice also contains vitamins and other anti-inflammatory factors.”

For the study, the team analyzed data from 1,068 mother-child pairs. The women were asked about the quantity of beverages they consumed daily, including sugar-sweetened drinks and fruit juices.

By mid-childhood, one out of five kids born from moms who drank sugary beverages had developed asthma.

The researchers also note that they cannot prove sugary drinks cause asthma, but rather that there is a correlation between the two.

The study was published online on Dec. 8 in the Annals of the American Thoracic Society.