Child sex-specific adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for ASD per 6.5 g/m3 PM2.5 during each exposure period. Separate models were estimated for each time window, and estimates were adjusted for birth year, KPSC medical center service areas, maternal age, parity, maternal race/ethnicity, maternal education, census tract median household income, maternal history of comorbidities before pregnancy, and family specified as a random effect. Circles represent the hazard ratios and whiskers represent the 95% CIs.