Association between Maternal Smoking during Pregnancy and Asthma in US Children and Adolescents by Race from the National Health and Nutrition Examination Survey (1999-2018)

BACKGROUND The independent effects of maternal smoking during pregnancy and risk of asthma in early childhood has been identified in numerous studies, but few have attempted to understand this relationship in adolescents and different racial groups. OBJECTIVE The aim of this study was to identify the impact of maternal smoking during pregnancy on current asthma in both children and adolescents and the difference in the association by race. METHODS Children aged 2-18 in NHANES (1999-2018) who had available information on maternal smoking during pregnancy and asthma history were included. Logistic regression was used to determine the association between maternal smoking during pregnancy and current asthma in children and adolescents while adjusting for confounders. The analysis was then stratified according to race. RESULTS While no association was found in the overall population, stratified analyses revealed a significant association between maternal smoking during pregnancy and childhood asthma in Mexican American (OR, 2.31 95% CI, 1.38-3.87) and Hispanic (OR, 3.89 95% CI, 2.00-7.60) children. CONCLUSIONS The observed association between maternal smoking during pregnancy and childhood asthma was not uniform across the population but was instead confined to specific racial/ethnic groups highlighting the importance of stratified analysis in diverse populations.