The investigative team in Canada found that pre-pregnancy weight may possibly influence a child’s risk of developing pediatric allergic diseases.
A recent Canadian study found that maternal weight may have consequences on allergic disease development in offspring.
According to the investigators, led by Sebastian A. Srugo, MSc, School of Epidemiology and Public Health, University of Ottawa, the findings supported the involvement of maternal pre-pregnancy body mass index (BMI) in pediatric allergic disease development.
They also mentioned that allergic diseases had reached “epidemic proportions” globally, with approximately 30% of the Canadian population suffering from at least 1 allergic disease.
Earlier studies suggested that Insufficient or excess maternal weight and weight gain during pregnancy could alter the immunological development of the fetus through low-grade inflammation, insulin resistance, and metabolic dysregulation.
The studies were supported by growing evidence that linked BMI and gestational weight gain (GWG) to common allergic diseases such as asthma, rhinitis, and dermatitis.
Using population-based health datasets, Srugo and investigators assessed the relationship between maternal pre-pregnancy BMI and GWG on the incidence of anaphylaxis, asthma, dermatitis, and rhinitis in offspring, and hypothesized that deviations from adequate BMI or GWG would increase the hazards of allergic disease development.
Srugo and colleagues first performed a population-based retrospective cohort study of singleton live birth between April 1, 2012, and March 31, 2014 in Ontario.
Infants in the study were followed up for approximately 5 and 7 years, or until the end of the study on March 31, 2019.
The investigators used data sources such as the Better Outcomes Registry & Network (BORN) Ontario Information System (BIS) to define the birth cohort, which included maternal-newborn records for all births of at least 500g and at least 20 weeks of gestation.
The Canadian Institute for Health Information's Discharge Abstract Database (DAD) and National Ambulatory Care Reporting System (NACRS) captured hospital admissions and emergency department visits, respectively. The Ontario Asthma Surveillance Information System (ASTHMA) captured asthma diagnoses from the above datasets through a validated algorithm.
Prior to the sensitivity analysis, exposure assessments for pre-pregnancy BMI and GWG were established.
For the study, BMI was categorized based on World Health Organization groupings into underweight (<18.5 kg/m2), normal weight (18.5–24.9 kg/m2), overweight (25.0–29.9 kg/m2) or obese (≥30.0 kg/m2).
Of the 248,017 infants included in the study, approximately half were born to overweight or obese mothers.
In the follow up, 1184 (0.5%) infants were diagnosed with anaphylaxis, 33,336 (13.4%) with asthma, 54,119 (21.8%) with dermatitis and 8076 (3.3%) with rhinitis.
Interestingly, pre-pregnancy obesity was associated with reduced hazards of anaphylaxis and increased hazards of asthma.
No associations were found between pre-pregnancy BMI and rhinitis or between GWG and any allergic outcome.
Findings on GWG and pediatric allergic disease were inconsistent, likely due to the lack of studies on the subject. Overall, Srugo and colleagues found that maternal weight, but not GWG, might have contributed to allergic disease development in offspring.
The investigators recommended a stronger focus on pre-pregnancy BMI.
“Interventions to promote normal pre-pregnancy BMI may, therefore, be an important and cost-effective upstream target to ease the epidemic trends of allergic diseases in childhood,” the team wrote. “Future work should aim to assess the impact of maternal and paternal health behaviours before, during and after pregnancy on this relationship.”
The study, “Examining the role of pre-pregnancy weight and gestational weight gain in allergic disease development among offspring: A population-based cohort study in Ontario, Canada,” was published online in Pediatric and Perinatal Epidemiology.