Hey Mama! In the final weeks of your pregnancy, it starts to set in that you will actually have to birth your baby. EEK! Lots of emotions there! So when your doctor drops a bomb saying that your baby is “measuring big”, it can really ramp up the anxiety and leave you doubting your ability to have the birth you’ve pictured. Let’s sort through the myths and facts about Big Babies (aka fetal macrosomia) so you can have an informed and empowered birth experience!
First things first, a couple of fast facts:
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- Macrosomia (aka the medical term for “big babies”) occurs for about one in 10 babies at birth.
- Male babies are often “bigger” than females.
- Genetics and a higher BMI can potentially lead to larger babies.
- A diagnosis of Gestational Diabetes, or diabetes prior to pregnancy, has higher rates of large babies, in comparison to those who do not have a diabetes diagnosis.
While it’s true that big babies can potentially cause risk factors in delivery, it’s not worth jumping to conclusions based on speculation alone. In fact, research shows that the care provider’s perception that a baby is big can actually be more harmful than a big baby by itself when it comes to unnecessary interventions.
Why I am here and who I am:
Hey mama, I am Trish— AKA Labor Nurse Mama. I am a labor and delivery nurse with over 15 years of high-risk OB experience. I am also a mama to 7 kids and have given birth to 6. This means I am quite familiar with the postpartum period and how to navigate it. I am the online birth class educator for Calm Labor Confident Birth and The VBAC Lab birth classes and the mama expert inside our Calm Mama Society, a pregnancy & postpartum membership community! I am passionate about your birth and motherhood journey! You can find me over on IG teaching over 230k mamas daily. I am passionate about your birth and motherhood journey!
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Ultrasounds are Often Wrong About Size
If your provider looks at your ultrasound and says that your baby is measuring big, there is a 50/50 chance that they are correct. Seriously, Mama! You can flip a coin and come up with the odds of that one being true. Making crazy plans based on an estimate is not cool!
According to Evidence Based Birth, 1 in 3 women are told that their baby is “big” by the end of pregnancy, but statistically, only 1 in 10 babies is actually considered to be big at birth!
What about 3D ultrasounds? While they are all the rage for the realistic peek you get inside the womb, 3D ultrasounds are not any more accurate in predicting baby’s weight than 2D ultrasounds.
Ultrasounds can give us a lot of information about what is going on with baby, but when it comes to predicting their weight, they are not the gold standard for accuracy. The more ya know!
What About Shoulder Dystocia?
Shoulder Dystocia is the name for when a baby’s shoulders get stuck under the pubic bone during delivery. There are two main concerns with this: 1) The risk of baby losing oxygen if their body doesn’t follow their head out in a timely manner and 2) there is a risk of permanent nerve damage in the shoulders if they get stuck.
Now Mama, these are certainly risks to consider, but it’s important to look at the numbers to put things in perspective. The data tells us that anywhere from 7-15% of all babies have a difficult time squeezing their little shoulders out, without any serious consequence.
A study from 2019 shows that shoulder dystocia occurs in approximately 6% of babies who are born larger than 8lbs 13 oz and only 0.6% of babies who weigh less. When babies weighed more than 9lbs 15 oz, there was a 14% chance of shoulder dystocia. Additionally, the risk of shoulder dystocia is also higher for Mamas who have gestational diabetes, regardless of baby’s birth weight.
So yes, it is possible for baby to get a bit stuck, but the data shows us that this is a serious complication but not a common problem that results in injury. Something to take into consideration! But also, consider that many of the mamas who had a shoulder dystocia were also pushing on their back during vaginal delivery. Hmmm.

Induction Isn’t the Only Choice
If your provider speculates that your baby will be big, they may be quick to jump on the induction train.
But hold on there, Mama! Induction isn’t always the best choice. In fact, research shows that it doesn’t eliminate the risk of shoulder dystocia completely; it drops the risk rate from 7% to 4% and actually increases the risk of a severe tear.
Induction also increases the need for multiple interventions, including things like a vacuum, episiotomy, and other assisted delivery means, like a cesarean delivery.
While many providers say that inducing before term and based on gestational age will reduce the risk of dystocia and the need for a cesarean section, the research does not back up this conclusion.
Cesareans Also Carry Risks
Mama, if your baby is “measuring big” your provider may have already thrown around the idea of a planned c-section. You know that moment when the provider is measuring your fundal height and palpating your belly during a visit, and they make that little noise and suggest your baby is big.
Let’s be clear: Predictions of baby’s weight are not accurate and they are definitely NOT a reason to have an elective cesarean birth if you do not want one.
Recommending planned c-sections to prevent complications from a “big baby” is not only extremely expensive, but with the risk of shoulder dystocia fairly low, it would take thousands of planned c-sections to prevent even one injury caused by a baby getting stuck!
Not to mention, c-sections are not risk-free. They are major surgery, after all!
Risks of cesarean sections include infection, severe bleeding, and damage to blood vessels or organs. Plus, there is an increased risk to the baby’s health and the need for a NICU stay with c-section birth.
While c-sections are life-saving procedures, they should not be the first line of defense for delivering a big baby!

Pushing Position Matters
If you’ve been told that your baby may be big, it doesn’t mean you will need to be induced or plan a c-section, but you should consider doing a little research on the best positions for your labor.
In fact, ACOG (American College of Obstetricians) does not recommend induction or cesarean for a suspected big baby alone! (suspicion is not fact)
Can I give you a tip, Mama?
GRAVITY. If your baby is big, using gravity to your advantage will be key to helping your baby wiggle out of a tight space and into your arms!
This means you should not birth your baby while laying flat on your back.
I repeat: Do NOT let anyone tell you that you need to be flat on your back while pushing!
When it comes to pushing—especially if you’ve got a big baby on board—you need to be in a position that will allow your pelvis to be open.
Being on all fours, using a squat bar or a birthing stool will be a huge help in making sure your baby has plenty of space to move through the birth canal!
Your Body Made Your Baby
Being told your baby may be “too big” (it pains me even typing that) can naturally cause a bit of stress. But rest assured, Mama, you can trust your body. It is wise, strong, and resilient!
Say it with me, Mama: My body knows how to birth the baby that it grew.
It is extremely rare for your pelvis to be “too small” to birth your baby (not to mention, it’s very hard to actually diagnose!)
Your body has done amazing things and has brought you so far. It will not grow a baby that it cannot birth. You just have trust her!
Psst! Check out even more amazing birth Mantras here and tips for creating your own!
In the case of Gestational Diabetes
Gestational Diabetes is when a mother has issues with blood sugar that indicate diabetes, but only during pregnancy. The risk of gestational diabetes is that the baby can actually grow to be too large and need intervention, like induction. This is why it is so important to control your blood sugar through diet and healthy lifestyle changes. Not only does it prevent inductions or cesareans, but also prevents a more difficult birth and birth trauma.
In this case, measuring growth via ultrasound do tend to be more accurate for mothers with gestational diabetes, simply because these Mamas are more likely to have a big baby in the first place!
An important note: Just because you have gestational diabetes does NOT mean that your baby will be too big!
Mamas who have been diagnosed with gestational diabetes can manage their blood sugar through changes in diet and exercise, or through medication if needed. This allow you to also manage your own weight gain and the untoward symptoms. A high blood sugar level brings a wealth of issues for you mama.

Let’s be honest: The thought of birthing your baby can be a little nerve-wracking.
Like how is THAT going to fit through THERE?
So when you hear that you’re going to have a “big baby,” it can add a whole level of anxiety and the picture you have for your birth.
Mama, I hope you see that you can absolutely advocate for your birth even if your provider hits you with that “big baby” scare.
Your body was made to carry and birth this baby, and it will not grow a baby that it can’t birth!
You are strong, brave, and equipped to bring your baby earth side.
Cheering you on!
Oh, one more thing!
