It is exactly the number of months a baby spends in the womb.
Explanation:
In George Orwell's "Nineteen Eighty-Four," <u>Winston is tortured for a period of nine months in order to change his perception of The Party</u>. In that respect, O'Brien acknowledges the Party intends to brainwash Winston until he is trustworthy. For that reason, the prisoner is finally taken to Room 101 to be re-educated, where he is tormented by his worst fear: hungry rats.