We recently shared a birth announcement on Instagram that sparked a huge response. One of our clients had delivered her 11 lb. 7 oz baby vaginally at our birth center, and did so without complications. While stories like this may seem rare, they’re more common than you might think.
At the Midwives of New Jersey, we want to reassure women that a vaginal delivery of a large baby is often not only possible, but also safe. Too often, women are told their baby is “too big,” and are rushed into cesarean sections without evidence-based reasons. In reality, many women, especially those who’ve given birth before, are capable of natural births even with big babies.
What Is Considered a Large Baby?
A baby is typically labeled large for gestational age (LGA) when their birth weight is in the 90th percentile or higher for their weeks of pregnancy, usually more than 8 pounds, 13 ounces (4,000 grams). When a baby weighs more than 9 pounds, 15 ounces (4,500 grams), the condition is referred to as fetal macrosomia.
While a baby’s size can introduce some challenges during delivery, it’s not an automatic reason for surgical birth. Many women successfully deliver large babies vaginally, especially with proper support, mobility during labor, and patience.
How to Know if a Baby Might Be Too Large for Vaginal Birth
Certain signs during pregnancy and labor may raise suspicion that the baby could be too large to fit through the birth canal. These signs aren’t definitive but may include:
Excessive Weight Gain or Poorly Controlled Gestational Diabetes
Weight gain during pregnancy that exceeds recommended guidelines, especially when paired with gestational diabetes, can increase the risk factor for fetal macrosomia. Managing blood sugar levels through diet and exercise during pregnancy may help reduce this risk.
A Baby Floating High in the Pelvis
If the baby remains high in the pelvis after labor has started, it may indicate that the baby’s size is incompatible with the pelvic shape or alignment.
Prolonged or Inefficient Labor
Slow progress or ineffective contractions may be a sign that the baby’s head is not engaging well or that labor isn’t progressing as it should, particularly in vaginal births of large babies.
Baby’s Head Not Being Well-Applied to the Cervix
When the baby’s head isn’t well-applied to the cervix, dilation may stall. This can happen with any baby but is more common when the baby is large or in an unfavorable position.
Failure to Descend
The baby not moving down during labor can indicate a tight fit or suboptimal alignment between baby and pelvis.
Prolonged Second Stage of Labor
If a woman, especially one who has delivered vaginally before, pushes for an extended period without progress, it can suggest increased risk of complications like shoulder dystocia.
Persistent Occiput Posterior Position
Babies in the OP position often take longer to navigate the pelvis. Large babies seem to favor this position and may settle near the sacrum for more space.
Common Misconceptions About What Determines a Large Baby
Some indicators are often misunderstood or misused to suggest a baby is too large for vaginal delivery:
“Big Belly” = Big Baby?
Not necessarily. A prominent belly can reflect maternal weight gain or fluid levels rather than the baby’s weight.
Short Stature
A petite woman can absolutely deliver a large baby. Pelvic capacity varies widely and doesn’t always correlate with external appearance.
Past Due Date
The assumption that more time equals a bigger baby isn’t always true. Birth weight varies. Some large for gestational age babies arrive early, and some smaller babies are born post-dates.
Ultrasound Size Estimates
Ultrasound is notoriously poor at accurately predicting a baby’s size near term. Research has shown significant error margins, yet this method is still used to recommend cesarean delivery.
A Prior Cesarean Doesn’t Mean You Can’t Deliver a Big Baby
It’s common for a first cesarean to be due to “failure to progress,” often without true cephalo-pelvic disproportion. Many women who have a Trial of Labor After Cesarean (TOLAC) go on to deliver even larger babies vaginally. Success rates for TOLAC range from 60% to 80%, depending on individual circumstances.
We’ve supported women who had a first cesarean due to a “big baby,” only to have a successful vaginal delivery of an even larger baby the next time. It’s worth going into labor and seeing what your body is capable of, no matter the suspected size of your baby.
We had a client whose whole family made large babies-they all gave birth without needing a cesarean section. Knowing that, she came to her first birth confident that the baby would be big and even more sure that she could deliver without surgery. Her plan was for a homebirth. The labor was long but normal for a first-time Mom. She pushed a couple hours at home then transferred to the hospital. We started a Pitocin drip to strengthen the contractions and she pushed again for a couple hours. In the end, the 9#14oz baby took an alternate route into the world.
When this woman returned pregnant with her second baby, she wished to have a TOLAC. But then at the end of the pregnancy, it was evident that this baby would be as big as the last. Conversations between Mom, Dad, our doctor and I led to a decision to schedule a repeat cesarean 4 days after the due date.
On her due date, she called me and said she had started labor. She was anxious about enduring labor pain just to end up in the operating room again, so she made her way to the hospital. Long story short, she delivered her second baby about an hour after admission. 10#15oz, no problem! Obviously, the first cesarean was not a sign of a cephalo-pelvic disproportion; it just happened. As you can see from this person’s experience, it is often worth going into labor instead of just scheduling surgery.
Best Practices to Avoid an Unnecessary Cesarean Section
If you’re expecting a large baby, here’s how to give yourself the best chance at a natural birth:
Go Into Labor Spontaneously
Avoid elective induction unless medically necessary. Allowing labor to begin on its own helps the baby and mother align optimally.
Rest Early, Move Later
In early labor, rest. Later, movement is crucial. Walk, sway, climb stairs, and use a birthing ball to help the baby descend into the birth canal.
Avoid or Delay an Epidural
While pain management is important, early epidurals can interfere with pushing and reduce pelvic mobility. Avoid the epidural or at least delay as long as you can – a woman needs to be able to push very effectively if the baby is bigger. Epidurals not only take away sensation, but they paralyze the pelvic floor. Consider turning if off for the 2nd stage of labor before exhausting yourself pushing without effect.
Be Patient and Trust the Process
Sometimes labor with a big baby takes longer, and that’s okay. With continuous support, patience, and proper positioning, many large babies are born vaginally without issue. You do not know what you (and your pelvis) can do until you try!
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