Maternal house dust–related cleaning behaviors during pregnancy and neurodevelopment from 18 months to 3 years of age in the Japan Environment and Children’s Study

To examine the association between maternal house dust–related cleaning behaviors during pregnancy and neurodevelopmental outcomes from 18 months to 3 years of age. Data from 81,125 mother–child pairs who participated in the Japan Environment and Children’s Study (JECS) were analyzed. Mothers were asked about cleaning behaviors intended to reduce house dust exposure during pregnancy, including how often they vacuumed their living room floor and futon, how often they aired their futon, and whether they used an anti-mite cover for their futon or bedding. Child development during toddlerhood (ages 1.5, 2.0, 2.5, and 3.0 years) was assessed using the Japanese Ages and Stages Questionnaires, Third Edition (J-ASQ-3). Generalized linear models were used to calculate adjusted odds ratios (AORs) relative to the groups with the lowest frequencies of cleaning during pregnancy. Model 1 was adjusted for maternal factors, and Model 2 was additionally adjusted for socioeconomic and dwelling environment factors. A higher frequency of house dust–related cleaning behaviors during pregnancy was associated with lower odds of screening positive for developmental concerns in offspring between 18 months and 3 years of age (Model 1 AOR range: 0.74–0.97; Model 2 AOR range: 0.68–0.98). A graded association was observed with increasing levels of cleaning frequency. Maternal house dust–related cleaning behaviors during pregnancy were associated with lower odds of screening positive for developmental concerns in offspring between 18 months and 3 years of age. Because these behaviors were assessed as proxy indicators of household environmental management rather than through direct measurements, the findings should be interpreted as observational associations requiring confirmation using objective environmental exposure assessments.