Childbirth Connection angered that estimated fetal weights are merely estimates


The Childbirth Connection is the leading lobbying organization for the natural childbirth industry. Their apparent goal is greater employment for the women they represent: midwives, doulas and childbirth educators. The heart of their marketing strategy is to promote distrust of modern obstetrics and obstetricians. As I noted almost exactly one year ago today, getting your information on birth from the Childbirth Connection is like getting your information on solar power from Big Oil. The conflict of interest is gargantuan.

[pullquote align=”right” cite=”” link=”” color=”” class=”” size=””]Better maimed than Cesarean shamed.[/pullquote]

Their latest effort to promote distrust of obstetricians is embodied in two recent articles, When a Big Baby Isn’t So Big in the NYTimes, and, Are Women Being Tricked Into Having C-sections? by Beth Greenfield, who often serves as a conduit for the natural childbirth industry, in Yahoo Parenting.

From the Yahoo piece:

[R]esearchers … found that a significant number of women are being erroneously told that they would be having big babies. And the study, published in Maternal and Child Health Journal in December and based on the data of 1,900 women surveyed by Childbirth Connection, further showed that mothers who believed they were having big babies were nearly five times more likely schedule a C-section — even though the large majority of their babies wound up weighing less than 8 pounds 13 ounces …

“Estimating weight is still an imprecise science. But the study is really more about communication than anything else,” one of the researchers, Eugene R. Declercq, a professor at Boston University School of Public Health, tells Yahoo Parenting. Figuring that a baby will be big, rather than too small (and then at greater risk of problems), he notes, “should be conveyed as good news, with no question about it being able to be delivered vaginally.” But based on the study’s findings, that’s not what’s happening, as a doctor telling a mom-to-be that her baby will be big “has a profound effect, and contributes to undermining women’s confidence they can deliver the baby,” Declercq told the New York Times.”

See! See! It shows you that obstetricians don’t know what they are talking about. It shows you that they just want to trick women into C-sections. How dare obstetricians fail to inform the public that an estimated fetal weight is merely an estimate? How was anyone to know?

The articles make it sound like this is some sort of shocking discovery, but obstetricians are well aware of the fact that estimate fetal weights are … gasp … estimates. Moreover, we are also aware the the accuracy of estimated fetal weights declines as the baby gets bigger. In the third trimester, EFW is accurate only to within +/- 2 pounds. A baby with an EFW of 9 pounds may weigh as little as 7 pounds, but it is EQUALLY likely that it weighs as much as 11 pounds.

There’s a simple reason why EFW is an estimate. It’s the equivalent of weighing a child with a tape measure. If you were told a child’s age, height, head size and abdominal circumference, you could probably come up with a pretty good estimate of its weight. That’s essentially the same information that ultrasonographers use to calculate the EFW.

Why does fetal weight matter anyway?

Here’s why: the baby’s very life may depend on it.

In another recent study that examined the relationship between increasing birth weight and perinatal mortality among 5,049,104 liveborns in the United States between 1995-2000, a nadir was observed at approximately 3,900 g and a sharp rise occurred for newborns with higher weights (see the image below). Thus, depending on many factors, the optimal birth-weight range to minimize the risk of fetal and maternal morbidity and mortality is between 3000-4000 g.


We know that very large babies have a much greater risk of paralyzed arms (Erb’s palsy), brain damage and death. We know that our best methods of estimating fetal weight can be off by two pounds in EITHER direction. What’s the solution?

The obvious solution is to develop more accurate ways of estimating fetal weight. In the meantime, we have to make do with what we have in attempting to prevent injury and death.

But that’s not how the folks at the Childbirth Connection see it. What are they doing to develop new, more accurate methods of measure fetal weight? Absolutely nothing. They don’t want to improve existing technology because … never forget this … their goal is NOT to make childbirth safer; their goal is to make vaginal birth more common, and their go-to tactic is to demonize obstetrics and obstetricians.

Listening to the Childbirth Connection declaim on the risks of technology is like listening to Big Oil declaim on the risks of solar power. There is a massive conflict of interest. But in the case of the Childbirth Connection and obstetricians, there is also an extraordinary conflict of VALUES: the Childbirth Connection values process whereas obstetricians have a laser-like focus on outcome.

That’s why obstetricians are constantly working to improve the accuracy of their technology while the natural childbirth industry, represented by the Childbirth Connection, resorts to demonizing it. The Childbirth Connection want you to hire a midwife and a doula to preside over your unmedicated vaginal birth. If that means taking a chance that your baby will end up injured, brain damaged, or dead, so be it.

As far as the Childbirth Connection is concerned, better maimed than Cesarean shamed.