Prenatal exposure to gas stoves, mold, and water damage: Associations with gestational duration and fetal growth in the ECHO cohort.

Epidemiological evidence on prenatal exposure to household environmental factors (gas stoves, mold, and dampness) and adverse birth outcomes remains limited and inconsistent. We examined associations of these exposures with gestational duration and fetal growth in 11,483 mother-infant dyads from 31 sites in the United States Environmental influences on Child Health Outcomes (ECHO) Cohort. Participants reported presence of a gas stove, mold/mildew (outside the shower/bathtub), and water damage in the home where they lived for the longest duration during their pregnancy (2000-2023). Gestational age at birth and birth-weight-for-gestational-age z-scores were primarily abstracted from medical records and analyzed continuously and categorically. We used covariate-adjusted linear or logistic regression models with a random effect for site to examine primary associations. We conducted exploratory analyses to assess effect modification by maternal race/ethnicity, education, hood/fan presence/use, and home construction year. Among participants, 53% reported having a gas stove; 13% reported mold/mildew; and 15% reported water damage. Overall, these exposures were not associated with birth outcomes. Several instances of effect modification were observed, particularly between mold/mildew and water damage and shorter gestation. Adverse associations with mold/mildew were more pronounced in newer homes (early-term odds ratio [OR] = 1.35, 95% confidence interval [CI]: 0.98-1.84) and among mothers with higher educational attainment (preterm OR = 1.44, 95% CI: 1.01-2.06). Conversely, the inverse association between water damage and preterm birth was stronger among non-Hispanic White participants (OR = 0.70, 95% CI: 0.50-0.97). This large multi-site study observed no consistent associations between the measured household environmental exposures during pregnancy and gestational duration or fetal growth.