The title(and the words to the song)suggests that the woman is finally
   getting a second baby after over 5 months of her pregnancy. The
   scatting Louis does("oo, ah")in the song suggests not only labor pains,
   but also the man's impatient longing to see the baby ASAP! Yet even so,
   the song does not use too many words, so I am unsure about the complete
   meaning of the song. The "oo ah" scatting made me laugh because Louis
   puts some great soul and ecstasy into it. Once I laughed, I couldn't
   stop it, and that's why I admire this swing song highly.