Thursday, May 6, 2010

An Interesting Perspective on Post- Datism

I came across this from a couple of friends who sent this to me a year or two ago. It really sheds an interesting light on the fears surrounding postdatism. It is an exerpt from a forum on the subject, by an Australian doctor.

"In the eight years when I practiced homebirths as a registered

doctor, out of 1,190 bookings I had 106 post mature babies (more than forty-

two weeks) of which three went to forty-eight weeks, a few more went to

forty-six weeks, and lots went to forty-four weeks—and all those babies

fared very well. I did lose one at forty-two weeks, which is not outside

the obstetricians' limit. Of those 106 post mature babies, only one fitted

the textbook description of post maturity, looking like a little wrinkled

old man with stained skin, but that baby was extremely alert, and insisted on

looking around the room instead of suckling.

What decided me to do no inductions for post-maturity was a very early

mother in my homebirth series who refused induction despite my anxiety,

went to forty-four and a half weeks and gave birth to a chubby pink,

strong,healthy baby, with absolutely no sign of post maturity. If I had lost

one of those 106 babies who went past forty-two weeks, obviously I would have

done some deep soul-searching, but I doubt whether I would have changed my


Babies mature at different rates, not at exactly forty weeks, just as

we adults do not become senile at seventy years.

Some might say I was lucky to deliver 106 post mature babies without

losing one, but remember that my clients were mostly very health-conscious,

especially regarding diet. None of them was driven to homebirth by

financial difficulties—quite the reverse. In Australia it is far cheaper to

birth your baby in hospital. I should also mention that I tend to disregard

meconium as a supposed sign of fetal distress, because of other possible causes,

for example, if the mother took laxatives.

I feel the advice from the midwives was always correct. I would not

rely on ultrasound to establish dates. The best check, if the mother presents

early enough, is that before ten weeks the fetal heart is more than 160,

often 180, but by twelve weeks it usually settles to 144 or less. But my

present mood is—don't be fussy about dates. When you estimate the due date (I

use 283 days, i.e. nine months and ten days, slightly more accurate than

the received forty weeks), also advise the prospective parents not to tell

friends and relatives the precise date, but be vague, like "before the new

year" or "before Thanksgiving," so that they will not be pestered by

nervous well-wishers if they go past the "due" date.

Marion's response in The Birthkit Issue 25 is very good ["A CNM

Discusses Post maturity Syndrome"], but I must take issue with one sentence. She

says "Post maturity syndrome has recognized signs, and that's why the

pediatrician who tried to resuscitate Barbaranne's baby knew it was forty-four

weeks." With the background of my experience with post mature babies, which is

far more comprehensive than most other practitioners under the rule of

induction at forty-two weeks or earlier, I have to assert categorically that the

so-called recognized signs of post maturity are fallacious because

babies mature at different rates. Those signs are practically never due to

real post maturity, they are more likely to be due to other factors like a

severe illness during pregnancy, or placental infarction well before term. I

knew that post maturity signs were unreliable long before I ever started

attending homebirths, because I can still remember the famous and respected

pediatrician Kate Campbell telling us students about post mature

babies having long hair and long fingernails and other signs, and premature

babies having the reverse. But once I got into general practice and was

delivering babies in hospital, I noticed that those signs were most unreliable,

and that some babies born before term had long fingernails and hair, and

some babies born after term did not. In any case I cannot share Marion's

confidence that the pediatrician who tried to resuscitate the baby

knew it was forty-four weeks, even though he said so. I know pediatricians and

obstetricians better than to trust a statement like that."

Dr. John Stevenson

Victoria, Australia