DWCAP , I was guessing the CC payments were a result of the medical bills. Quite often, when one doesn't have insurance, you end up having to guarentee your treatment on a CC. I would have guessed that they simply couldn't afford the medical payments, and let the interest on the CC ratchet up.
However, like I said, I can't think of why a reason for the 5th child. I mean, it's not exactly "oops" on the 5th child. You think one would have learned on the 3rd or 4th "oops".