We are expecting a baby very soon - the due date is December 6.  We
would like statistics regarding actual delivery vs the due date.  What
are the percentage chances of delivering over a week before our due
date / within a week a before / on the due date / within a week after
/ within 2 weeks after / more than 2 weeks after? I know the
statistics vary by race and number of deliveries: my wife is caucasian
and this is her frist delivery.  I would like statistics from a recent
and reputable medical source as there are plenty of sites out there
with "old wive's tales" about this subject.  If you can provide
similar data, but not exactly broken down in the way I have described,
please ask for clarification. Thank you.

Welcome to almost-fatherhood.  As a dad of two young hellions, I can
promise you that what you're in for is exactly what you expect, and
like nothing you expect.  All the best to you and your family.

As to your question, I was quite surprised when my wife was pregnant
at the variability in due date estimates.  We knew precisely when
conception was, but still, the doctor gave different due date
estimates based on different assessments, which differed yet again
from the estimate of the sonogram specialist who we saw mid-way
through.  Of course, none of the estimates were right, and when my
first born arrived, our Ob-Gyn was actually on vacation and we had a
pinch-hitter.

Anyway, I don't know if this sort of variability is common to other
parents' experiences, but with several possible due dates to choose
from, it would be hard to pin down how accurate (or not) any of them
were.

Hello
This is an interesting read
Birth.com
http://www.birth.com.au/class.asp?class=66&page=4
only 5% of babies will be born on their estimated due date even if the
exact day of conception is known. The issue of 'how' the EDD was
determined is influential in determining the accuracy, e.g. knowing
the conception day or last period, and if allowances were made in the
calculation for the accuracy of the period as not all women have a 28
period cycle.
I missed the birth of my Son as he was two weeks early and I was on
the other half of the globe! I missed him by 3 days, (my return flight
was 3 days after his actual birth day, but well before his EDD.
regards
lot-ga

Congratulations!

As a mother of two (ages 6 and 10), let me give you a quick hint: 
babies show up when they're good and ready to, no matter what any
doctor ( or statistician!) says.  The simple fact of the matter is
that the doctors don't know either.

My OB swore my eldest would arrive on or very near May 25th, which
sounded about right to us, as when knew when we conceived.  My darling
boy hung in there til June 5th, the day I was scheduled for induction
of labor, and has been consistently late for everything ever since.

His little brother wasn't much better.  He arrived five days after his
EDD.

If you don't already have it, I highly recommend that you check out
"What To Expect When You're Expecting" for more information on the
subject.  IIRC, Arlene Eisenberg addresses the subject of due dates
and their fickleness rather matter of factly.

Good luck!  May your wife's labor be short, your baby be healthy and
sweet, and parenthood be just as much an adventure for you as it has
been for me!  Kids are so much fun!

--Missy