bun in the oven

[kentishbear]

where did the saying "bun in the oven" meaning to be pregnant, come from and when was it first used?

thanks

[Clanad]

One source offers this:
"...The phrase is 20th century. The first citation I can find is in Nicholas Monsarrat's Cruel Sea, 1951:

"'I bet you left a bun in the oven, both of you,' said Bennett thickly... Lockhart explained ... the reference to pregnancy."

[scotman]

Cassell's Dict of Slang indicates that oven is 1940s+ slang for womb hence bun in the oven

[kentishbear]

thanks for the answers :)