Are baby possums born in the pouch?

First, you should understand that the term 'Possum' refers to the Australian species of this animal (of which there are over 80 species). The north American 'Opossum' are about 70 different species. All Possum or Opossum are born from the womb, out of the vaginal tract and make their own way into the pouch with strong forelimbs. North American Opossums have 13 teats in the pouch so the first 13 pups to get them will survive. If there are more , they will die in a day or two. The pups in the pouch will live there, attached to a teat for up to 3 months.