Tuesday, April 22, 2008

Doing Math for the Doctor

Joni has felt a little pressure from her doctors to consider scheduling an elective cesarean section for her birth because it is looking like the baby is going to be above-average birthweight.

The doctor told Joni that medical journals recommend c-sections if the baby is over 4500-5000 grams. "Or 9.5 to 10 pounds." That's what he said. The implications were that if the ultrasound next week "determines" that Elias is 9.5 pounds or above, then we should opt for a c-section

However, a quick check of his math reveals that he's off:
4500 grams is 9.921 pounds, pretty darn close to 10.
5000 grams is 11.023 pounds. That's 10% heavier than the 10 pounds he stated.

So, the threshold for when you need to start thinking of having a C-section is actually 10-11 pounds, and NOT 9.5-10 pounds. His statements made it sound like above 10 pounds is getting past the safety threshold, when the journals he's quoting don't even recommend it until after 10 pounds.

"Big deal, he's 1 to 1.5 pounds off," you might say. Well, if you're fine with a 10% margin of error then you might want to move on. But, I'm not, and I decided to take it a couple steps further.

The CDC allows you to analyze all kinds of birthing information by year. Demographics, methods, mortality rates, everything. The CDC reports that in 2005 there were 159,582 births of babies who were 9.5 pounds or more, or 3.9% of all births. 10+ pound babies accounted for 1.1% of births.*

If the journal recommends 5,000 grams or 11 pounds to have a c-section, then that's not many babies. Only 4,715 babies weighed more than 5,000 grams, that's .001 of all births.

So, why is it that now 31% of all babies come by C-section, and the number of elective c-sections continue to increase?

You've probably heard that question asked on the evening news. There are a number of factors, this MSNBC article mentions about a dozen. But "there is no question that malpractice issues play a part." Doctors have been sued for not performing c-sections by parents whose babies were injured during vaginal birth. It's also more convenient for all parties involved to just schedule a c-section rather than try natural birth and end up having an emergency c-section. A couple reasons why the U.S. has the highest C-section rate in the world, higher than the World Health Organization says is necessary to improve medical service.

So, was the doctor's mistake a mathematical one or did he purposely make it sound like we need to sign some paperwork if Elias looks to be 9.5+ pounds? I don't know, but you can bet I'll be at the doctor's office for the ultrasound next week.

Through the CDC site, I was able to look up vaginal vs. cesarean births for 28 year olds and the number of injuries that occur:

In 2005, for 4500-4999 gram babies (10-11 pounds) There were 7 injuries reported in 957 vaginal births (0.7%). There was one injury reported in 730 c-sections (0.1%).

For 5000+ gram babies (11+ pounds) there were zero injuries in 76 vaginal births. There was one injury in 109 c-sections (0.9%).**

So, the risk to the baby of a healthy 28-year old like Joni giving birth naturally to a baby 10-11 pounds is pretty slim. The risk is even more slim for a c-section. But, you have to weigh the slim differences in risk (0.7% vs. 0.2% total) against all of the long-term complications and risks of having a C-section.

For one, the mortality rate for mothers is higher with a c-section than that of vaginal birth. It's a major surgery. It creates complications for having future children that have to be considered. The list goes on.

It's not something that we can say "Well, he might be 10-11 pounds, so we might as well sign up for a c-section!" as if it's something on our gift registry. And I'll be happy to point out to the doctor what the data say.

So, next week we'll have an ultrasound to try and estimate Elias' size. I imagine that the accuracy and margins of error of an ultrasound will be my next post on the subject. :-)

(note: 2005 is the most recent year you can get detailed data. The CDC lists them in weight groupings [4000-4499 grams], so I had to multiply by the percentage difference to get to 9.5 pounds, so there is some slight estimation. So, give or take 20 babies).
** (There were more births of both types in 2005, but many did not state on the certificate whether or not injuries occured. So, the "unknowns" are left out of the analysis).


Andrew's Mommy said...

I know that everything is totally your all's decision, but I am TOTALLY APPALLED that the DR would even suggest that. I know people that were told their babies were that size, but the ultrasounds were never on target. The babies were always smaller than they thought. I thought Joni's post was right on about trusting God. IF there is a major medical emergency, then c-sections are an option, but if there is no reason to thing that something is wrong, then I just don't understand the suggestion of a cesearan. Best of luck and may your Doctors on the day of delivery be magnificent for you both.

Jill :)

JTapp said...

Thanks, Jill. You guys definitely know about big babies!

The doctor also recommended Joni drink a glass of wine in the evenings to help her insomnia. That one really surprised me.

Nick said...

Then you also have the inaccuracy of the ultrasound as a form of measurement itself. Our doctor basically said it was +/- 1 lb. (i assume for an average-sized baby).

For us it must have been pretty close - they estimated 8 lbs, and a week later at delivery he was 9 lbs 5 oz. So it was an underestimation of 1 lb 5 oz., minus whatever he grew that week. (1/2 lb?)

JTapp said...

I'm going to look into ultrasound this week. I want to get an accurate and official +/-, and see how the technology works.

Mollie said...

Justin you rock!! Way to do a little research and get informed!!! I'm definitely going to keep this in mind should this come up for us!!

Anonymous said...

Geez! Do Joni and I have the same OB?? I'm sure feeling pressured to schedule a C section. After one totally natural delivery, one C section (much worse than the one with no drugs), and a third due in about 2 weeks I'm starting to feel a little beaten down from all the fearsome stories about what could go wrong. It is SO good to hear someone else question the doc's whether their efficiency is as solid as PR makes us think! Hugs to you both! Oh,and we have an Elias too. What good taste in names you have!