Air pollution during pregnancy poses severe documented risks to fetal development, withas harmful pollutants crossingcross the placenta, and directly interferinginterfere with critical growth stages whileand triggeringtrigger maternal inflammation and oxidative stress. Research demonstrates strong associations between prenatal exposure to specific PM2.5 components — particularly sulfate and ammonium — and increased autism risk, withwhile the second and third trimesters representingshow especially vulnerable windows. These pollutants disrupt normal fetal brain development and raise risks for premature birth, low birth weight and long-term neurological consequences.