Medical Statistics Weigh Against Internet Rumor That Palin’s Fifth Child Isn’t Hers

There are accusations across the leftwing blogosphere, including at Liberal White Boy and Dailykos, that Sarah Palin's fifth child, Trig, her Down's Syndrome baby, is actually her daughter's. The main evidence is that Palin didn't look pregnant when she said she was 6 or 7 months pregnant last winter, and that her daughter Bristol was out of school for several months with mono. I was at a party tonight where a guy in developmental biology pooh-poohed the rumors on statistical grounds, saying that the odds of a 44-year-old woman having a Down's baby are remarkably high, while the odds of a teenager having a Down's child are infinitesimal. Just throwing that in. (Commenter Gannon here makes the same point.)