Microscopic particles in air pollution inhaled by pregnant women may damage fetal cardiovascular development. The study found that one exposure late in pregnancy can restrict maternal and fetal blood flow, which can continue to affect the child into adulthood.

See the source article by following the link below:
Microscopic particles in air pollution inhaled by pregnant women may damage fetal cardiovascular development. The study found that one exposure late in pregnancy can restrict maternal and fetal blood flow, which can continue to affect the child into adulthood.