Prepregnancy obesity associated with increased risk for wheeze in offspring

Prepregnancy obesity increased risk for wheeze in offspring, although excessive gestational weight gain generally was not associated with atopy, according to a study published in Annals of Allergy, Asthma & Immunology.

“Our research group is interested in how early life exposures may affect child development and health outcomes,” Kristen J. Polinski, PhD, a postdoctoral Intramural Research Training Award fellow in the epidemiology branch of the division of population health research at NIH’s Eunice Kennedy Shriver National Institute of Child Health and Human Development, told Healio.

Noting that prepregnancy obesity and high weight gain during pregnancy are prevalent in the United States, Polinski added that asthma and allergic conditions are among the most chronic diseases affecting children with potential origins early in life.

“It’s hypothesized that prenatal exposure to obesity, which is considered a state of low-grade chronic inflammation, may impact fetal development and contribute to the child’s risk of developing these conditions,” Polinski said.

The researchers examined Upstate KIDS Study data from 5,034 mothers and their 6,171 children born in New York between 2008 and 2010. Researchers evaluated the mothers’ prepregnancy BMI and self-reported gestational weight gain (GWG), noting differences in these factors based on maternal age, marital status, smoking during pregnancy, insurance status and gestational diabetes.

Also, questionnaires provided data on wheeze, eczema, atopic dermatitis and food allergies by the time children were aged 36 months and again when they were approximately aged 7 to 9 years. New York’s SPARCS longitudinal inpatient and outpatient hospital discharge data system provided data on more severe cases of asthma and allergy.

By the time children were aged 36 months, 10.8% had persistent wheeze, 39.2% had any atopy, 28.2% had eczema/atopic dermatitis and 10.2% had any food allergy. By the time they were aged 40 months, SPARCS data showed 3.8% had at least one ICD-9 code consistent with an asthma-related condition and 0.9% had at least one ICD-9 code consistent with any allergy-related condition.

The researchers also found 16.5% of children to have current asthma, 10.4% to have eczema, 16.7% to have physician-diagnosed allergies in the previous year and 14.2% to have allergy medication prescribed in the previous year in middle childhood.

The risks for persistent wheeze increased among children of mothers with class I obesity (adjusted RR = 1.45; 95% CI, 1.03-2.03) and class II/III obesity (aRR = 1.51; 95% CI, 1.08-2.11) compared with mothers with normal weight before pregnancy.

Also, the researchers found a borderline association between maternal class II/III obesity and decreased risk for eczema/atopic dermatitis in early childhood (aRR = 0.81; 95% CI, 0.66-1), but not class I obesity (aRR = 1.03; 95% CI, 0.87-1.22).

The researchers did not observe any significant effects with food allergy or atopy overall in early childhood, nor did they find any significant associations with asthma or eczema by middle childhood.

However, the researchers found a positive association between prepregnancy BMI and reported allergy, but not allergy medication use, in middle childhood.

Also, the children of women whose prepregnancy BMI was classified as overweight were more likely to have reported allergy compared with the children of women with normal prepregnancy BMI (aRR = 1.72; 95% CI, 1.18-2.51).

The researchers found no associations between GWG and persistent wheeze, asthma or eczema, nor were there statistically significant associations between prepregnancy BMI and any severe allergy or asthma requiring inpatient/outpatient care. Similarly, there were no associations between GWG and severe allergy episodes or asthma-related ICD-9 codes.

“Our study adds to prior work supporting associations between a mother’s weight and asthma and allergy conditions in the child. This is important because this kind of research provides evidence that a woman’s health during pregnancy can affect her child years into the future,” Polinski said.

Polinski specifically noted that the children of women with prepregnancy obesity were more likely to have at least two reports of wheeze by the time they were aged 3 years, which is considered a potential indication of early asthma, in addition to links between higher prepregnancy weight and reports of allergy in kids aged 7 to 9 years, but not early childhood allergy.

Polinski cautioned that the implications for clinical practice are limited because the study was not designed to prove cause and effect.

“Although no single risk factor can entirely account for childhood asthma and allergy, prepregnancy obesity is a modifiable lifestyle factor in which health care providers should continue to promote optimal preconception weight and healthy weight gain during pregnancy,” she said.

Polinski also said that these results support previously published research and provide evidence that prenatal exposure to obesity may have long-term effects on children.

“However, a better understanding of the mechanisms of early and middle childhood asthma and allergic conditions is needed,” she continued. “From a public health perspective, efforts to target preconception care are warranted to support women of reproductive age in achieving and maintaining a healthy prepregnancy weight.”

For more information:

Kristen J. Polinski, PhD, can be reached at kristen.polinski@nih.gov.