Of Viruses, Big Babies and Ultrasound...

March was a wacky month - filled with viruses (computer and human) that slowed down my progress here and elsewhere. I've had dozens of things I'd like to write about, but not the energy nor a computer that could keep up with a little word processing.

I'm grateful to finally be recovered - just a little cough for me, a little hiccup here and there for the computer (but I blame Microsoft for that). Now if I could just figure out what's happening with my cell phone...

There are untold adages about how things happen in sets (or groups of sets), and any one of them would fit the last few weeks for me. In particular, it's been a month of "big" babies. Two of my students gave birth to girls who weighed more than eight pounds -- a hearty congratulations to both families on their wonderful new daughters! -- and two clients are currently wrestling with their physicians over inducing their babies early because of estimated weight.

In my years as a childbirth instructor and doula, I've worked with a number of moms who've given birth to babies larger than nine pounds...often without a perineal tear. I've been there for the rare occasion when a baby could only be born by c-section, but I've seen many, many more moms give birth to big babies with no complications, no anesthesia and no undue stress.

So it disturbs me to see more doctors trying to convince women to induce because they think the baby might be large. In the vast majority of situations, a mom allowed to labor the way her body needs to -- even if the resulting labor is longer than average -- can give birth to her baby without surgery. Even if the birth results in a c-section, the benefits to the baby of going through a trial of labor are substantial. Labor massages the baby's organs, resulting in a baby who's better able to breathe and otherwise function after birth.

Physicians are scheduling more ultrasounds late in pregnancy, which allows them to use the "the baby's too big!" argument to justify induction. Late-pregnancy ultrasounds are often less-than-accurate at determining the baby's size or gestational age (in which late-term ultrasounds may be off by as much as 21 days).

In 2006, a group of London researchers looked at this issue -- performing ultrasounds to estimate the weights of 262 babies immediately before labor was induced. Using two common formulas for measuring, they found that ultrasound estimates were off by more than 10 percent in 38-58 percent of cases. Ultimately, doctors were more accurate guessing baby's weight than using ultrasound to try to determine it, the study concluded.* Moms were more accurate in some cases at guesses their own baby's weight than one of the two ultrasound formulas tested. "All four (estimates) were significantly different from birth weight," the study concluded.

Some doctors tell women they need to induce early or schedule an early c-section because a big (or macrosomic) baby could be damaged by the birth process. However, it seems that these procedures aren't making a difference in the health of babies or moms.

In a 2005 article in the American Journal of Obstetrics and Gynecology**, authors note: "Among uncomplicated pregnancies, there is sufficient evidence that suspected macrosomia is not an indication for induction or for primary cesarean delivery."

As much as the labor process benefits babies, waiting to be born until the baby is ready is of a huge health benefit to the baby as well. The March of Dimes is currently campaigning to educate physicians about the differences in the brain of a baby born before 40 weeks and that of a baby born at 40 weeks or after. The differences are significant, the organization reports. For example, the baby's brain at 35 weeks is only two-thirds the size of a 40-week brain. Babies born early have poor feeding reflexes and are more likely to suffer learning and behavioral problems, according to the March of Dimes.

I often wonder marvel at the disconnect that seems to exist between those doctors who birth the baby (Yes, I know, it's the mom who births the baby, not the doctor!) and those who take care of it once it's born. It seems unlikely that doctors would push so hard to induce babies if they thought about the lingering effects for children and parents.




* Original Paper
Clinical and ultrasound estimation of birth weight prior to induction of labor at term
E. Peregrine, P. O'Brien, E. Jauniaux
Department of Obstetrics and Gynaecology, University College London Hospitals, London, UK


** American Journal of Obstetrics and Gynecology, 2005 Aug;193(2):332-46.
Suspicion and treatment of the macrosomic fetus: a review.
Chauhan SP, Grobman WA, Gherman RA, Chauhan VB, Chang G, Magann EF, Hendrix NW.
Spartanburg Regional Medical Center, Spartanburg, SC, USA.