Final answer:
Infections, trauma, congenital disorders, and exposure to toxic substances can lead to neurologic changes during pregnancy.
Step-by-step explanation:
During pregnancy, several events can lead to neurologic changes. Infections, such as encephalitis or meningitis, can affect the nervous system and cause loss of function. Trauma, like blunt force trauma from accidents, can physically damage the central nervous system (CNS) and result in widespread neurological deficits. Additionally, certain congenital disorders and exposure to toxic substances, like alcohol or lead, can impair neural development and cause birth defects.