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“Big” Babies and Small Hips: Should Mamas Be Concerned?


For this small-framed mama with a healthy appetite, those are perhaps the most comforting words one can hear in childbirth class. You see, during my first pregnancy I wore a sign around my neck that said “Tell me every possible terrifying birth scenario you can think of, then tell me I’m going to change my mind about natural birth after the third contraction.” It was there, I’m sure. I never actually saw the sign, but what else could account for all the dire predictions I encountered while carrying my sweet baby?

Turns out, a Lot

The overall message to mothers and fathers-to-be in our culture seems to be that birth is an emergency. Women are bombarded with scary birth scenarios on TV, then are told by their doctors that their “hips are too narrow” or that baby is “definitely a 9-10 pounder.” Here’s the problem with that: weight estimates based on ultrasound are notoriously inaccurate notoriously inaccurate and at least one study one study indicates that predicting a “big baby” increases a woman’s likelihood of having a caesarian—even if the baby turns out to be average size! Theories about why happens vary, but some say doctors develop opinions about whether labor will “work” based on the weight estimate and then label situations as “failure to progress” more quickly than they otherwise would.

Unfortunately, not only are weight estimates inaccurate, the actual weight of a baby does not solely determine whether a vaginal birth is possible. In Africa, an “80-pound Pygmy mother typically gives birth to an eight-pound baby.” That’s the equivalent of a 130-pound woman birthing a 13-pound baby! (sourcesource) Obviously, there is more to this than just the numbers.

Bottom line: far too often a woman’s faith in her own body is needlessly undermined. But does this mean that birth is as easy for us as it was for the women before us? Not necessarily. Due to nutritional deficiencies and lifestyle factors, birth can sometimes be a bit more challenging for modern women. In most cases it is absolutely possible, but being aware of what’s changed gives us the opportunity to work toward the very best outcome.

Vitamin D Deficiency and the Pelvic Brim

In the 18th and 19th centuries, poor nutrition, rickets and illnesses such as polio caused pelvic anomalies, which resulted in loss of life during childbirth. Indeed initially CPD was the most common reason for carrying out a caesarean. In modern times, however, CPD is rare, since our general standard of living is so much higher and true CPD is more likely to be caused by pelvic fracture due to road traffic accidents or congenital abnormalities. (sourcesource)

While I agree that our standard of living is in some ways higher than conditions in 18th and 19th century Westernized populations, the primary factor behind rickets and pelvic abnormalities—Vitamin D deficiency—is still very much with us.

In a 2009 study, researchers found about 70 percent of children in the U.S. aren’t getting enough Vitamin D. (sourcesource) Of course, deficiencies in vitamins A & K also contribute, but the association is not as widely known. While thankfully most recent cases are not severe enough to cause rickets, they can cause changes in a young girl’s pelvic formation that could affect labor later in life. In a girl with optimal pelvic formation there is a nice round opening, while those who have less optimal formation have a more oval opening. This is of course a generalization. You can read more about the different shapes of pelvises and the advantages/challenges they present here hereand herehere.

Though we can do far better for our daughters by nourishing ourselves with a traditional diet during preconception, pregnancy and breastfeeding as well as nourishing our daughters throughout childhood, our formation is already complete. Fortunately, those of us who had less than optimal nutrition during our formative years can still usually go on to have vaginal births. Here’s why:

Pelvis Structure: Setting the Record Straight

The good news about the pelvis is that it is “a flexible structure. It has joints. The body produces a hormone called relaxin during pregnancy. This hormone is designed to loosen those joints to prepare them to open up during birth. . .The baby’s head is also a flexible structure. It, too, has joints. The baby’s skull can compress and mold, and the plates of the skull can even overlap, in order to get the baby out.” 

In plain English, what this means is that even with a less-than-ideal pelvic brim, many women are able to give birth vaginally. In fact, one study found that of women diagnosed with absolute cephalopelvic disproportion—a pelvis officially declared too small for birth—68 percent went on to have a vaginal birth! (sourcesource)

As someone who did not have optimal nutrition during my formative years and who tends to have long, challenging labors, I take comfort in the success of these women. Birth may not be as easy as it would have been if we’d been well-nourished all along, but there are ways to increase our odds of a vaginally delivery if that is what’s desired.

Five Ways to Optimize Your Chances of a Vaginal Delivery

While there are many factors that can increase a mama’s odds of having a vaginal delivery—nutrition, education, and a supportive birth team to name a few—today I want to focus on making sure the pelvis is properly aligned and prepared for birth. Here are my top five suggestions:

Sit on a Birth Ball throughout Pregnancy

If baby is in the optimal anterior position, he/she will be able to tuck his/her chin during labor, which makes squeezing through the pelvis easier. Unfortunately, modern ways in which women sit—such as leaning back in big overstuffed chairs or couches—encourages baby to settle in the opposite position (posterior). Sitting upright or with your belly slightly forward “helps the abdomen be a hammock for the baby and encourages the baby to settle in an anterior position,” so for optimal fetal position, try sitting on a birth ball rather than a chair when you can. Here’s how to use your birth ballHere’s how to use your birth ball to help position your baby for birth.

Chiropractic Care

During pregnancy, the Webster technique can be very helpful for encouraging baby to settle in the optimal position. Regular care can also correct subluxations that might otherwise prevent proper biomechanics as the pelvis widens during labor. Personally, I found that receiving an adjustment during my last labor played a vital role in moving things along. I’m currently expecting my third child and have already asked my chiropractor to make a house call if needed!

Use Strategic Positions during Labor

Did you know that squatting during labor can increase pelvic measurements by up to 25 percent? It’s true! (source) Many sources actually say it’s closer to 30 percent. By using positions that open the pelvis (squatting, all fours, standing, sitting on a birth stool) you can dramatically increase the likelihood of a vaginal birth. Though very convenient for physician, lying flat on one’s back is probably the least effective position to give labor in. It puts the mother’s weight on her coccyx, which restricts movement and may make it difficult for the pelvis to open. (It also causes gravity to work against the mama and increases the likelihood of tearing and/or an episiotomy.)

Hire a Doula

I’ve had two home water births—one without a doula and one with. Trust me: if you can fit it in your budget, it is definitely worth it! Doulas can often suggest position changes based on their observations of how labor is progressing as well as soothe mama with pain management techniques. Plus, according to an analysis of six studies covered in Mothering the Mother: How a Doula Can Help You Have a Shorter Easier and Healthier Birth, having a doula present can reduce caesarian rates by 50 percent.

Laboring Is Beneficial No Matter the Outcome!

Sometimes in an effort overcome the mountain of “can’ts” thrown out by the medical community and media regarding birth, I believe we may accidentally create an environment that is unfriendly to moms struggling with disappointments about their experience. There are times when caesarians are necessary, and mamas are no less strong, or committed, or loving if things don’t go according to plan. It’s sometimes unavoidable, and mothers who choose their baby’s best interest over their “ideal birth” should be given a big hug and asked to join the circle where we all share our stories.

To those who labored and did not have the outcome they wanted, I applaud you. The very act of labor triggers physiological changes thataffect the composition of breast milk, encourage the production of oxytocin, and help clear the lungs of fluid. Birth is important, but it is just the beginning. Let’s nourish our daughters so that they can experience the ease of birthing with a wide pelvic brim, and of course let’s nourish our son’s too!

About Heather

Heather Dessinger, aka The Mommypotamus The Mommypotamus, is a wife, blogger and mom to two amazing kiddos, both waterborn at home. She loves all things fermenty, talks to sock puppetstalks to sock puppets, and dreams of owning her very own flock of backyard chickens. She is the author of two ebooks.Nourished Baby Nourished Baby is a simple guide to introducing real food to little ones, and DIY Organic Beauty Recipes DIY Organic Beauty Recipes is a collection of 50+ beauty and personal care product recipes that really work.