Saturday, November 3, 2012

"What?? You are past Your Due Date? Be Careful Your Water Doesn't Break On Me!"


It happens to us natural birth folks all the time.

Our lovely "due date" comes and goes just like any other day.

 I have had all four of my babies at 8 days past my estimated due date. An estimated due date is just that an estimate that was put forth by a doctor in the early 1800’s. However we still follow his rule as if it were gospel doctrine. In reality less than 1 % of babies when left to nature would be born on their due dates. So what is all the fuss about? We as Americans like things on a schedule. And you can’t schedule birth. At least not birth the way it was meant to be. So what are our options?  A midwife named Carol Wood Nichols came up with a new solution. Both Naegele’s Rule and Wood Nichol’s Rule are explained below.

Naegele’s Rule-
 Franz Karl Naegele was born July 12, 1778, in Düsseldorf, Germany. In 1806 Naegele became ordinary professor and director of the lying-in hospital in Heidelberg. His "Lehrbuch der Geburtshilfe," published in 1830 for midwives, enjoyed a successful 14 editions. The rule estimates the expected date of delivery (EDD) (also called EDC, for estimated date of confinement) from the first day of the woman's Last menstrual period (LMP) by adding a year, subtracting three months and adding seven days to that date. This approximates to the average normal human pregnancy which lasts 40 weeks (280 days) from the LMP, or 38 weeks (266 days) from the date of fertilization.

LMP = 8 May 2007
+1 year = 8 May 2008
-3 months = 8 February 2008
+7 days = 15 February 2008
or +9 months and +7 days only (this way the year will change automatically).
(280 days after 8 May 2007 would be 12 February 2008.)

Wood’s Method-
 Carol Wood Nichols. 
First-time moms with 28 day cycles: LMP + 12 months - 2 months and 14 days = EDD
Second-time moms or more w/ 28 day cycles: LMP + 12 months - 2 months and 18 days = EDD
Cycles longer than 28 days: EDD + (days in cycle -28 days) = EDD
Cycles shorter than 28 days: EDD - (28 days - days in cycle) = EDD

So how does this affect real life? Let’s us an example.  Let's say I have a client who according to Naegele’s Rule with a LMP of November 25th 2012 would have an EDD of August 31st 2013.
Now contrast that to the same client using the Wood’s Method. With a LMP of November 25th 2012 it would give her a due date of September 7th 2013.

But that is 8 days difference? So is my client currently 10 days or 2 days past her due date?
It makes a big difference. When I have my own practice I think I will take the two methods and average the date between them to get a more realistic guide as to when to expect baby to make its appearance. But in the end it doesn’t really matter. Left to their own accord babies choose when they are ready to be born and all we can do as midwives is welcome and support them in their time.

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