Meconium Aspiration: It’s Not As Bad As You Think

Whether you’re past your due date or just trying to get informed, you might be wondering what the deal is with meconium aspiration, i.e. when baby poops in the womb and breathes it in. Well, I’m here to tell you all about it—and the outlook is better than you might think.

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Pregnancy and birth teach you a whole new vocabulary. One of those new words is “meconium.”

I’m guessing since you’re here you’ve learned a bit about meconium, but I’ll reiterate just to make sure. Meconium is a baby’s first poop. It’s dark and super sticky and is usually out of a baby’s system within a day or two or birth.

Most of the time, babies don’t poop out meconium until after they’ve been born. But sometimes they poop while still inside their mother’s uterus. Usually, this isn’t a cause for concern. It’s fairly common and isn’t usually dangerous.

Yet in most hospitals, it’s treated like it is dangerous. That’s because occasionally a baby breathes in meconium and experiences what is called “meconium aspiration syndrome.” It can be serious, but severe cases are rare.

Many women are worried about meconium aspiration, especially if they’re considering an out-of-hospital birth. But even in cases of aspiration, most babies will be just fine. And outcomes would likely be even better if more care providers did things a little differently. 

And that’s why I’m writing this blog post today…so that you know what to ask for to give your baby the best chance of avoiding meconium aspiration.

Is Pre-Birth Meconium Dangerous?

As I said, meconium is sticky. Like, really sticky. It can be hard to get it off a baby’s bum. (Put olive oil on your baby’s bum before putting their first diaper on to avoid this!)

If it’s hard to get off skin, it’s easy to see why it could be dangerous if it gets inside their airways. 

But there are a few important clarifications here.

Swallowing vs. Breathing

First, it’s one thing for a baby to swallow meconium. It’s a different thing for a baby to inhale meconium into their lungs.

While babies are in the womb, they practice “breathing” and peeing and naturally swallow amniotic fluid. In fact, by about 20 weeks of pregnancy, amniotic fluid is mostly made up of the baby’s sterile urine, which they’ve swallowed and peed out again.

If a bit of meconium (which is also sterile) gets into the amniotic fluid and the baby swallows it, they’ll just pee it out.

On the other hand, if a baby inhales meconium, the sticky substance can lodge in their lungs and make breathing extremely difficult.

Meconium Staining vs. Meconium Aspiration

The second thing to note is that just because there’s meconium in the amniotic fluid doesn’t mean the baby will breathe it in or experience meconium aspiration. 

Somewhere between 5 and 20% of babies will be born with some meconium in their amniotic fluid. This is called meconium-stained amniotic fluid, or simply “meconium staining.”

But of those babies who have meconium staining, only 5% will experience meconium aspiration. 

To understand what that means for your baby’s actual risk, let’s look at one large study.

A 2011 study found that 16.5% of babies who are born at full term (after 37 weeks but before 42 weeks) have meconium staining. So if we use that as our baseline, then the actual number of babies who experience meconium aspiration (5% of that) is 1 out of every 121, or 0.825%.

And, like I said earlier, even for those babies who do experience meconium (that 1 in 121), the outcomes are good the vast majority of the time.

One study found that for those babies that did have meconium aspiration syndrome, 81% of them went home without any intensive care, 16.9% of them had intensive care but recovered, and 1.2% died.

Is Meconium Aspiration Preventable?

It’s not clear exactly what leads some babies to breathe in meconium and not others. And that means it’s hard to prevent.

But we do know that some things increase the chances of meconium aspiration.

It’s generally agreed that distress during late pregnancy or during labor is one of the biggest predictors of meconium aspiration syndrome.

For example, if oxygen is restricted during labor because of abnormally strong contractions (through the use of Pitocin, usually), that baby is more likely to take gasping breaths while still in the womb.

And if there is meconium in that baby’s amniotic fluid, he or she will likely inhale some of it.

Other factors that increase the chances of meconium aspiration include:

• Post term pregnancy (42+ weeks)
• Fetal growth restriction
• Oligohydramnios (low amniotic fluid)
• Infection in the vagina or surrounding tissues
• Preeclampsia
• Maternal drug use

Avoiding these things may reduce the chances of your baby experiencing meconium aspiration.

How Do Doctors Handle Meconium Staining?

Because of the risk of meconium aspiration, many doctors routinely suction babies’ airways as soon as their head is born if they noticed any meconium in the amniotic fluid.

Then, when the rest of the baby’s body is born, they cut the umbilical cord and take baby to a warmer where they do more suctioning and observe how baby does for a while.

But experimentation and research have shown that that’s just not necessary.

In fact, the professional guidelines have recommended against suctioning all babies with meconium-stained amniotic fluid. (That’s been the recommendation since 2005! It just hasn’t been implemented by many doctors.)

And since 2015, the guidelines have said to leave babies with their moms, as long as they don’t show signs of distress, even if there was meconium in the amniotic fluid.

Guidelines aside, it just makes sense that babies do better when left with their mom—being warmed by her and feeling secure—and when their umbilical cords aren’t cut immediately. 

Treatment Options for Thick Meconium Staining

In the case of “thick meconium staining” (meaning there is actually poop in the water, it’s not just stained yellow or green), a more intense response may be needed.

If the baby isn’t born yet, doctors may do a procedure called amnioinfusion.

Amnioinfusion is the process of injecting sterile fluid into the uterus to increase amniotic fluid levels and therefore dilute the meconium. It can be effective, but, like everything, it has both risks and benefits. (Learn more about amnioinfusion here.)

If a baby is “non-vigorous” (meaning they show signs of distress after birth, including poor muscle tone, struggles breathing, or a low heart rate), additional treatments may be used, including:

• Checking baby’s blood oxygen level with a pulse oximeter
• Putting the baby in a warmer
• Doing a chest x-ray
• Connecting the baby to a breathing machine or giving oxygen
• Giving nitric oxide or surfactant (to supplement baby’s own production)
• Giving antibiotics for infection

Meconium Aspiration at Home

In a planned home birth setting with a midwife, meconium aspiration is no more common than it is in the hospital. If midwives notice meconium staining in a woman’s amniotic fluid, they will monitor the baby for signs of distress, as any care provider would.

But most midwives take a hands-off approach to this, as they do with most things.

Because meconium aspiration will usually have multiple indicators—not just meconium-stained amniotic fluid—midwives are generally comfortable letting labor proceed as planned, with no interventions. 

When a baby is born, they will watch his or her transition to life outside the womb closely, looking for signs of difficulty breathing. If the baby is not breathing or is struggling to take in oxygen, midwives know what to do and carry the equipment needed to help.

Most of the time, babies with meconium aspiration at home will not need to transfer to a hospital for intensive care.

Top Tip: Don’t Get Induced

Let me preface this section with a reminder that I am not a medical professional. And even if I was, I wouldn’t be your medical care provider. So always speak with your doctor or midwife about your specific circumstances.

That said, we know that stress is one of the biggest predictors of meconium aspiration. And induction of labor, especially by the use of Pitocin, often precedes fetal distress.

I call this the fetal distress cycle. In short, Pitocin causes contractions that are stronger, longer, and closer together than normal contractions. That means they’re more painful. Mom can avoid the pain by getting an epidural. 

But epidurals can weaken and slow contractions, so the Pitocin dosage will probably have to be upped after a while. But that makes contractions more painful. So the epidural dosage gets upped too.

All the while, the baby has no shield against the increased intensity of labor. If this goes on too long, the baby’s heart rate will likely start to decline because the contractions aren’t allowing enough oxygen to reach the baby.

And that is the definition of fetal distress.

And that means baby is more likely to inhale meconium, if there is any in the amniotic fluid.

So, in the absence of some other need for triggering labor early, avoid induction if you want to minimize the chance that your baby will experience meconium aspiration.

Conclusion: Stay Calm and Trust the Process

The truth about meconium aspiration is it happens. But it is more rare than common.

Beyond that, a baby can be in meconium-stained amniotic fluid and not experience aspiration.

And even for babies that do experience meconium aspiration syndrome, the outcomes are good the vast majority of the time.

If you want to decrease the likelihood of your baby having meconium aspiration syndrome, you can avoid induction and other interventions in labor, have your baby before 42 weeks, and keep yourself as healthy as possible to reduce your chances of experiencing things like preeclampsia and infection.

But most of all, stay calm. Make decisions from a place of education and trust in the process, not from a place of fear. That’s always the best way to go.

Until next time,

Allison