Twilight Zone the series. 2002.
One episode showed a woman in the future, going back in time to KILL Hitler as a child.
She ended up going back to when Hitler was a baby.
But instead, it showed her involvement in Hitler as a baby being killed, and another baby replaced him who was the real demonic one.
Back in that time period baby Hitler had a nanny/nurse maid.
When she saw that the real Hitler baby was dead, her fear of telling and facing Hitler's dad, well she went and got a baby from a woman who lived on the streets.
She replaced the real Hitler with another baby, and neither the Hitler's mother or father knew that it was not even their real son.