According to about.com 1 in 8100. There is a snippet about it at the bottom of the page at the following link.what are the chances of having "natural" tripletts? you know, without reproductive "assistance"...clomid, IVF, etc?
i know this is W-A-Y out there, but... maybe she was being paid to be a surrogate. didn't one article say she had lost her job? maybe she had not told her family knowing they would disapprove. implanted with several embryos and three "took". okay, okay... it sounds even crazier when i typed it out!
anyhow, such a sad situation.
http://multiples.about.com/cs/funfacts/a/oddsoftwins_2.htm