Congenital abnormalities of the kidney and urinary tract (CAKUT) are diagnosed in up to 1% of pregnancies and account for 20% to 30% of prenatal abnormalities. Because maternal obesity has been linked with congenital malformations in offspring, researchers led by Ian Macumber (Seattle Children’s Hospital) looked to see if it might have an impact on CAKUT.

Using linked birth-hospital discharge records from Washington State from 2003 to 2012, the investigators identified 3,221 cases, which were matched with healthy controls in a 1:4 ratio.

Compared with controls, mothers giving birth to infants with CAKUT were 1.3-times more likely to be obese. The researchers found a significant trend between the likelihood of CAKUT in children and higher categories of obesity. Being overweight, rather than obese, was not linked with CAKUT in children.

“Our findings add to the public health importance of obesity, particularly as a modifiable risk factor,” said Dr. Macumber. “The data supplement the literature regarding obesity’s association with congenital abnormalities and highlight the importance of future research needed to clarify the mechanisms of these associations.”