Assigned Week Of Delivery More Practical Than Obstetric Due Date
WESTPORT (Reuters Health) -
An 'assigned week of delivery,' determined through clinician skill and training, should replace the arbitrarily calculated due date, physicians in Eugene, Oregon, recommend.
'Assigned Week Of Delivery' More Practical Than Obstetric Due Date
December 3, 2001 WESTPORT (ReutersHealth) -
An "assigned week of delivery," determined through clinician skill and training, should replace the arbitrarily calculated due date, physicians in Eugene, Oregon, recommend. In the December issue of Obstetrics and Gynecology, Dr. Vern L. Katz and colleagues from Sacred Heart Medical Center note that physicians use dating to see how far a patient has progressed. In contrast, women use it to set expectations about a definite point in time when they will deliver, and many feel anxious if the date is exceeded.
"In our culture, being overdue is not a desirable quality," the authors point out. They add that the due date, never empirically established, "was derived by a 17th century botanist, Booerhave, who read in the Bible that pregnancy should last 10 lunar months."
The team proposes that patients be given an assigned week of delivery at 32 weeks' gestation, individualized for each clinical situation. For most pregnancies, the assigned week of delivery might be between 39.5 and 40.5 weeks' gestation, while a patient with twins would likely be given a week corresponding to 38 weeks' gestation and a primipara might receive a prediction of 40 to 41 weeks' gestation. The result would be that approximately 95% of all births would take place during the assigned week, Dr. Katz and his associates predict, improving both obstetric practice and patient satisfaction.
"The problem is that the term 'due date' has caused tremendous anxiety and tension over the last 3 decades because to patients, the concept of being 'overdue' has such a terrible connotation," Dr. Katz told Reuters Health. "Plus, we clinicians literally spend more time explaining why a person isn't really due on their due date than we spend on testing for AIDS, neural tube defects, and high blood sugars, and explaining what labor is like," he added.
He noted that this model has worked well for him and his co-workers. "I think that the paradigm will catch on, and that physicians and nurse practitioners will work harder and harder to get rid of the 'due date' concept," Dr. Katz predicted. "However, some may prefer to offer a 10-day window or a 5-day window, depending on the kinds of patients they see in their practices."
Obstet Gynecol 2001;98:1127-1129
The Due Date Myth
The 40 week due date that your pregnancy is set at is based on something called Naegle's rule, developed in the 1860's, that is designed by a 28 day menstrual cycle Since then studies have shown that different women carry different amount of days. First pregnancies last an average of 41.5 weeks, subsequent pregnancies last 40.5 weeks, Black and Asian women carry an average of 38.5-39.5 weeks. Those with longer than 28 day cycles carry 1 day longer for each day more their cycle is. If your cycle is shorter than 28 days, you carry 1 day shorter for each day shorter your cycle is.
If this isn't enough, figure in that depending on how and when your pregnancy was confirmed can significantly affect your due date. I.e. if your due date was set by ultrasound measurements, depending on when the scan was you have a 30-60% chance your due date is wrong. This is why induction for postdates often fails or is traumatic.because the women didn't go past her true due date, the doctors date was off to begin with and the baby wasn't ready yet.
Amy Jones
thebirthsource.homestead.com
2000
