Prepregnancy obesity risks wheezy babies
medwireNews: Children born to women who were obese before they became pregnant are at increased risk for frequent wheezing in early life, results from a Spanish study show.
Stefano Guerra (Centre for Research in Environmental Epidemiology, Barcelona) and colleagues found that pregregnancy obesity was independently associated with more than a fourfold increased risk for frequent infant wheezing in the first 14 months of life.
"These findings suggest that maternal obesity may predispose the offspring to respiratory health problems triggered by recurrent viral episodes, increased susceptibility to subsequent asthma phenotypes or both," comment the researchers.
"Indeed, the frequency of early wheezing episodes has been linked to subsequent asthma risk in several cohorts," they add.
The findings come from a study of 1107 mother-child pairs who participated in the Infancia y Medio Ambiente (Environment and Childhood) project.
Prepregnancy maternal weight was recorded at enrolment, with obesity defined as a body mass index (BMI) of 30 kg/m2 or higher and normal weight as a BMI of 18.5-24.9 kg/m2. Infant wheezing up to the age of 14 months was assessed using parental questionnaires, with infrequent wheezing classified as fewer than four episodes and frequent wheezing as four or more episodes.
The researchers found that the proportion of children with frequent wheezing was higher in those born to obese (n=68) than normal-weight (n=794) mothers, at 11.8% versus 3.8%. However, the proportion of children in these groups with infrequent wheezing was similar, at 32.3% and 30.7%, respectively.
After accounting for factors such as gender, preterm birth, birthweight, type of delivery, breastfeeding, and maternal age, smoking, and asthma, the team found that prepregnancy obesity was independently associated with a significantly increased risk for frequent infant wheezing, at a relative risk (RR) of 4.18, compared with a normal BMI before pregnancy.
However, pregregnancy obesity was not associated with a significantly increased risk for infrequent wheezing (RR=1.05).
Guerra et al conclude in Paediatric and Perinatal Epidemiology: "In this population-based birth cohort study maternal prepregnancy obesity was found to increase the risk of frequent wheezing in the infant by more than four times."
They add: "While the mechanisms for this association remain to be determined, these findings add evidence on the effects of in utero exposures on asthma-related phenotypes."
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By Mark Cowen, Senior medwireNews Reporter