Has your provider mentioned your baby is seeming large? Maybe you’ve had an ultrasound or you’re measuring big. Let’s talk about 3 things to think if you hear this, and where your mind should go moving forward.
This (or any article on The Pregnancy Nurse) should be taken as medical advice, this purely educational. Please talk with your provider about your specific needs and circumstances. Your provider’s assessment is very valuable information that you need to make a choice!
But first, how do I know so much about big babies? Hi, I’m Hilary — I’m The Pregnancy Nurse® — I’ve been a nurse since 1997 and I have 20 years of labor and delivery experience that has really opened my eyes to a few things on big babies. So, I’m excited to share them with you here today.
Before we get started — grab my doctor communication guide, because learning to talk with them is going to be number one as you move forward with this:
Things to do if your provider says you have a big baby:
First off, before we go anywhere — how did your provider determine this?
“Big Baby” is called Macrosomia or LGA (large for gestational age) in medical terms, FYI.
Tape Measure/ Leopold Maneuvers – A lot of people think this is far too LOW TECH to determine baby’s size, but through the year we’ve found this to be pretty accurate if we need to do something else. If you really are measuring off and they think something is up, they should get an ultrasound.
With the tape measure they measure from the top of your pelvis to the top of the uterus. In general, that should match in centimeters the # of weeks you are. So if you’re 35 weeks pregnant, it should be around 35 cm long.
With Leopold’s maneuvers a practitioner will feel you and your baby to determine baby’s size. Most practitioners use both the tape measure and some feeling at exams in your third trimester to see how things are going.
As you can imagine your body size can have some issues with them monitoring you this way. I’m a larger girl and I know it is harder for my doctor to feel the baby under my layers of fat than it is on a skinnier girl. Just something to think about as far as accuracy.
If they don’t order an ultrasound you can guess that they’re not too worried about it.
Ultrasound – Ordering a size/dates ultrasound is the next step they take when they think that baby might be big. They may also order this if you have other testing or have risk factors like diabetes or a previously big baby. We’re going to talk more about this, but this is a standard of care to see how baby is growing (and if one area of baby is growing faster than another area).
People get nervous because they haven’t had an ultrasound since 20 weeks as long as things are progressing normally. This is the recommend course of action and the FDA actually doesn’t recommend anymore than an early ultrasound to figure out your due date, and then an anatomy ultrasound at 20 weeks. Beyond that you’d need a reason to have an ultrasound, for the most part.
I’d love to join you during your pregnancy to talk about what to expect coming up (and what they’re doing at those check-ups):
Ultrasounds Can Be Off
This is the biggest thing. Depending on the ultrasound machine (and frankly, the tech). ultrasounds later in pregnancy can be QUITE off. I did a podcast with an ultrasound tech (it’s great, you can listen here) but she said that babies all grow the same for the first few weeks but after that their growth pattern varies quite a bit.
And, as the uterus fills it’s harder for the ultrasound to compensate for baby and how it is measuring it.
Think of looking for a person in a very empty room, vs looking for that person in a very full room and how much harder it is to find them. Your baby is now in a very full uterus which means that their measurements can plus OR minus 1-2 pounds (depending on the machine). That is quite a lot in a baby that, on average, only weighs 7 pounds.
It helps when you’ve had ultrasounds done at the same place that show baby growing more and more each week (vs a one-off ultrasound that baby is big).
This is not to discredit ultrasounds. Often ultrasounds are spot-on with baby’s weight, but as someone in the profession I have seen them be VERY off. I think we have to combine Ultrasounds, Leopold’s maneuvers, and mom’s thoughts on the matter to decide how big baby is.
Do you feel bigger?
I had always heard that moms can tell if baby is bigger or smaller than their last baby. I heard there was a study, but I couldn’t find it after quite a lot of searching.
But honestly, I believe this to be true. I’d often ask moms during my initial intake if they felt bigger or smaller than their last pregnancy and often that would tell out when we weighed baby — that mom was correct.
So, I think it’s a valid question if you’ve already had a baby (if you haven’t, you’re out of luck). Do you FEEL bigger this time, that could indicate an issue.
Tips like this come from providers with experience. They’re things not always studied but are true — so taking a class with an expert is smart!
Do you have a tested pelvis?
Again, this is for moms who have already had a baby.
Often your doctor will come to you saying that baby is measuring large, but you’ve already had a 10 pound baby out those hips! You make big babies (and hopefully you’ve done your glucose testing to make sure that isn’t the issue).
Having a tested pelvis is a pretty important part of your OB practice. It tells us a lot about what’s going on down there (which we can’t really tell otherwise).
So, those are three things to think of YOURSELF when doctor tells you have a big baby.
What are the risks of a big baby?
To be fair the risk of having a large baby can be pretty big.
There is the chance that baby will get stuck with it’s head out and we are unable to deliver the shoulders. It’s called a shoulder Dystocia and it can have disastrous consequences for both mom and baby. It is important to ALL of us to avoid that whenever possible.
You can also have a greater risk of bleeding as your uterus has been stretched so large.
Large babies can also have issues after birth, so it’s good for us to know ahead of time either way so we can take special care to watch for those (and possibly even have a neonatologist on standby).
What to do if you have a big baby?
Therein lies the question. What should you DO about it?
You could induce early — that can be an option to stop baby from growing any larger in the womb.
You could go straight to a c-section and bypass the pelvis.
You monitor it (wait). Often getting another ultrasound in a week to see if baby still looks big or what they think.
Honestly, those are the main things you can do. Obviously, if you have diabetes you’d want to make sure that is under control. But your provider (often with the assistance of a maternal fetal medicine doctor) will decide if they should recommend any of the above.
And then you can ask why they recommend what they did and then make the choice for yourself. Just make sure you understand the risks and the benefits of both sides before you make your choice. If you’re still not sure keep asking questions. Other things to consider:
- How accurate do you think that ultrasound is?
- Do you think I have a big baby when you measure and check on baby?
- What would happen if we waited a bit?
Often I see people immediately think that baby is big and they should be induced or should consider a cesarean. Just get as much information as you can before making that choice for yourself.
And remember, it’s YOU making the choice — not the doctor. They may say “I think you should be induced” but that doesn’t mean you need to think that too. I have a great podcast on balancing those with an OB you might enjoy.
I know it’s easy to think that once you make choice A or B you’re done with choices but labor is full of a LOT of choices and being prepared makes them SO much easier.
The Online Prenatal Class for Couples is the easiest way to get prepared for birth. You can do it in just about three hours — and is meant to engage both you and your partner in the learning process. Come join me!
The extra good news is that class covers inductions and c-sections and common interventions we do in the hospital so you’re prepared for ALL of those, no matter which route you and your baby take!
And, if you’re not quite sure you’re ready for that whole thing (but frankly don’t wait long — you need to get a class in), check out my free prenatal class. It’s your first step toward getting in the driver’s seat of your birth.
- About the Author
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A nurse since 1997, she has worked in various fields including pediatrics, geriatrics & hospice. She has 20 years of labor and delivery experience in the San Jose, CA and Phoenix, AZ areas.
As an evidence-based prenatal educator Hilary has delivered thousands of babies and has educated hundreds of thousands of parents from a diverse patient population to help them have a confident birth.