517 - Combined Effects of Smoking and Pre-Pregnancy BMI on Early Childhood Morbidity and Health Care Utilization

Publication Number: 517.4511

Sumera Aziz, University of Alberta Faculty of Medicine and Dentistry, Edmonton, AB, Canada; sarka Lisonkova, UBC, Vancouver, BC, Canada; YE SHEN, BC Children's Hospital Research Institute, Richmond, BC, Canada; Jeffrey N.. Bone, BC Children's Hosiptal Research Institute, Vancouver, BC, Canada; Lindsay Richter, University of British Columbia, Vancouver, BC, Canada; Joseph Ting, University of Alberta, Edmonton, AB, Canada

Background: Maternal pre-pregnancy body mass index (BMI) has been linked to various early childhood outcomes, yet the potential role of modifiable behaviors, such as smoking during pregnancy, in influencing this relationship remains unclear.

Objective: We aimed to examine the interaction between pre-pregnancy BMI and maternal smoking during pregnancy, and their combined effects on early childhood health outcomes.

Design/Methods: This was a retrospective population-based cohort study of children born between 2004 and 2012, with outcome data until five years of age (up to 2019). We retrieved data on pre-pregnancy BMI and smoking from British Columbia (BC) perinatal data and administrative health registries. BMI categories were underweight ( < 18.5kg/m2), healthy (18.5-24.9 kg/m2), overweight (25-29.9kg/m2), and obese (≥30kg/m2). Childhood outcomes including hospitalizations, emergency (ER) visits, intensive care unit (ICU) admissions, physician consultations, and early childhood morbidity were obtained from Population Data BC. We used Poisson regression to estimate adjusted risk ratios (ARRs) with 95% confidence intervals (CIs), adjusting for potential confounders.

Results: In the cohort of 546,867 mother-child dyads, 5.6% of women were underweight, 59.1% had normal BMI, 21.5% were overweight, and 13.7% were obese; 6.91% were smokers. [Table 1] Compared with children of normal-BMI women, the risk of hospitalizations, ER visits, physician consultation, ICU admissions, and morbidities relating to cardiology, endocrinology, gastroenterology, nephrology, mental health, sleep disorders, asthma, and infections increased with rising maternal BMI. The risk of allergies (ARR: 1.08; 95% CI: 1.05, 1.10), hematology (ARR: 1.27; 95% CI: 1.21, 1.33), dermatology (ARR: 1.14; 95% CI: 1.12, 1.16), and rheumatology (ARR: 1.12; 95% CI: 1.02, 1.22) disorders was higher for children born to underweight women. [Table 2 & 3]. Among smokers, underweight vs. normal-BMI women had higher risk of offspring ICU admissions (ARR: 1.18; 95% CI: 1.06, 1.32) and neurological disorders (ARR: 1.15; 95% CI: 1.05, 1.27); corresponding ARRs (95% CIs) were 0.97 (0.93, 1.91) and 1.09 (1.05, 1.13) among non-smokers. The risk of allergies and ER visits was higher among children of obese smokers than obese non-smokers. [Table 3]

Conclusion(s): Children of women with higher BMI require increased access to healthcare services. Children of both underweight and overweight women face unique morbidity concerns that warrant careful monitoring. Smoking modified the effects of maternal BMI on children’s ICU admissions, ER visits, allergies, and neurological conditions.

CV_Sumera_Aziz.pdf

Early childhood (0-60 months) outcome rates among women with singleton births by pre-pregnancy BMI, stratified by maternal smoking during pregnancy, n (%)


Strata specific adjusted risk ratios (ARRs) and 95% confidence intervals for the association between pre-pregnancy BMI and early childhood (0-60 months) health outcomes