February 23, 2017 0917 GMT
The specific developmental problems seem to differ depending on whether the mother, father or both parents are obese, according to researchers from the US National Institute of Child Health and Human Development, healthday.com reported.
"Specifically, mothers' obesity was associated with a delay in achieving fine-motor skills, and fathers' obesity in achieving personal and social skills — that includes skills for interacting with others," said lead researcher Edwina Yeung. She's an investigator in the institute's division of intramural population health research.
"When both parents were obese, it meant longer time to develop problem-solving skills," she added.
However, one pediatric neurologist, not involved with the research, isn't convinced that the study authors proved their case.
And Yeung acknowledged the same. "We used observational data, which doesn't allow us to prove cause and effect, per se," she explained.
The researchers did find that, compared with children of normal-weight mothers, children of obese mothers were 67 percent more likely to fail a test of fine-motor skills (using their hands and fingers) by age three.
In addition, children of obese fathers were about 71 percent more likely to fail tests of personal and social skills, which may indicate how well they relate to and interact with others, by age three, the researchers said.
Children whose mother and father were both obese were nearly three times more likely to fail tests of problem-solving ability by age three, the findings suggested.
According to Yeung, about two percent to four percent of the children failed any single test.
Yeung said she can't explain the apparent connection between parental obesity and kids' developmental problems. For maternal obesity, some animal studies have suggested that inflammation could affect the fetal brain, she said.
With paternal obesity, the effect on offspring might be due to either gene mutations or other inherited genetic factors in sperm, Yeung said.
Most research into understanding child health and development has focused on mothers and their pregnancies. "Our findings suggest that factors from fathers may also play a role and deserve attention," Yeung said.
The report was published online January 2 in the journal Pediatrics.
One child health expert doesn't think obese parents should be overly concerned by this study.
"Children of obese parents are not doomed to have developmental problems," said Dr. Ian Miller. He is a pediatric neurologist and director of neuroinformatics at Nicklaus Children's Hospital in Miami.
Any medical condition that affects the brain — such as lead-poisoning, sickle cell disease, iron-deficiency anemia, autism, epilepsy or cerebral palsy — can cause developmental problems, Miller said. He isn't ready, however, to add obesity to that list.
No matter whether parents are obese, normal weight or underweight, every child who might have a developmental problem should be screened and given help and therapy, he suggested.
Obesity may be a marker for increased risk of these problems, Miller said. The risk for developmental problems is low among all children, including those of obese parents. "It's not a 'sky is falling' type of scenario," he said.