Obesity During Pregnancy and Asthma Risk in Kids
Threat of respiratory disease may be up to 30 percent higher, study suggests
By Steven Reinberg
TUESDAY, July 22, 2014 (HealthDay News) -- Women who are obese during pregnancy may be more likely to have children with asthma than normal-weight mothers, a new review suggests.
"We found that, compared with children born from mothers of normal weight, those whose mothers were overweight or obese during pregnancy had up to 20 to 30 percent higher odds of asthma," said lead researcher Dr. Erick Forno, an assistant professor of pediatrics at Children's Hospital of Pittsburgh.
Forno's team also found that excess weight gain during pregnancy was associated with about a 16 percent increased risk of asthma in the children. "These results included studies that evaluated asthma at different time points in childhood, from a little over a year of age all the way to 16 years of age," Forno noted.
Although this review of more than a dozen previously published studies found an association between a mother's weight in pregnancy and her child's risk of asthma, it was not able to prove that a mother's weight is a direct cause of childhood asthma.
How a mother's weight might contribute to an increased risk of asthma in her children isn't clear. "It is important to clarify that the studies we analyzed did not directly evaluate the mechanisms involved in this association, so we don't know exactly how this link works," Forno said.
Several factors may be involved, he noted. "We know for example that obesity sometimes leads to inflammation that can contribute to diabetes or heart disease, and perhaps this inflammation in the mother somehow affects the developing lungs and airways in the baby," Forno said.
Or perhaps certain nutrients that mothers with healthier diets ingest may protect her offspring from asthma, he said. "Another mechanism may be that certain factors in the genetic make-up of the mother predisposes both to obesity (in herself) and to asthma (in her child). Most likely there is a combination of all these playing a role," Forno suggested.
Forno noted that it is important that all women of reproductive age maintain a healthy weight, especially if they are trying to get pregnant.
"It is also important to have adequate weight management and healthy nutrition during pregnancy, because excessive weight gain [during pregnancy] also increases the risk of childhood asthma. This is of course in addition to all the other benefits of a healthy weight and diet," he said.
The report appears in the August print edition of the journal Pediatrics.
Previous studies have found that obesity leads to an increased risk of asthma. And, among children with asthma, obesity leads to increased severity of the disease. There has also been increasing interest in the early origins of childhood asthma, Forno said.