Are Due Dates Accurate?

In a word, no. New mom and statistics geek spacefem is gathering and displaying data about gestation length and found that it varies widely depending on a host of factors. The "40 weeks" gestation used as a benchmark is the average and median for term births, but only 5.6% of spontaneous births happened on the predicted due date. The upshot is that you don't have to be "average" to be "normal". Spacefem also has graphs on the probability of induction by gestation date, birth weight by gestation date, and more. And you are invited to add your data to the ongoing survey as well! Link -via Metafilter