Cumulative maternal lifetime stress & child asthma: effect modification by BMI.

Background: Investigations of maternal psychosocial stress and child asthma have produced mixed findings, which may reflect inconsistent consideration of modifying factors.

Objective: To examine associations between maternal lifetime stress and child asthma, and to assess effect modification by maternal pre-pregnancy body mass index and race/ethnicity in a prenatal cohort of mother-child dyads.

Methods: Maternal lifetime stress was assessed using the Life Stressor Checklist-Revised, administered during pregnancy and child asthma was ascertained by parent-report in study follow-up visits. In the overall group and stratified by race/ethnicity, we used multivariable logistic regression and varying coefficient modeling to investigate the association between maternal stress and child asthma, assessing for effect modification by pre-pregnancy body mass index.

Results: Women were predominately Black (Black/Hispanic-Black 44.5%) or non-Black Hispanic (37.6%), with elevated pre-pregnancy body mass index (25.1% overweight, 29.8% obese); 17% of children had asthma. Higher maternal stress was associated with increased relative odds of child asthma only in dyads with women in the obese (≥30 kilograms/meters squared) category (odds ratio 1.84, 95% confidence interval 1.27-2.67). Varying coefficient models demonstrated stronger positive associations between increased maternal lifetime stress and child asthma in women with higher pre-pregnancy body mass index; the strongest association was observed in the Black group.

Conclusion: Maternal pre-pregnancy body mass index modified the association between maternal lifetime stress and child asthma. These findings underscore the need to consider complex interactions to fully elucidate intergenerational stress effects on early childhood asthma.