Where did this term originate?

Question

Where did the term "knocked Up" come from for describing when a woman becomes pregnant

Answer 1

From the Online Etymology Dictionary:

"Knock" comes from the Old English word "cnocian," and the meaning "deprecate" or "put down" is from 1892. ... "Knock up," from 1663, had the meaning of "arouse by knocking at the door;" however it is little used in this sense in American Engish, where the phrase means "get a woman pregnant" (the phrase first came about in 1813), possibly from the the word "knock" as in "to copulate with" (first found in 1598, coming from the 1860 slang phrase "knocking-shop," meaning "brothel").