Meconium: What To Know About Baby's First Poop

Learn what meconium is and why it looks the way it does. Plus, find out what a healthy baby's poop should look like as they get older.

From the moment of birth, one of the most common questions parents ask is "Is my baby's poop normal?" The first poop babies make will look thick and tar-like, and may be very hard to clean up. The good news? This poop is called meconium--- and it's completely normal.

Today, we'll cover what meconium is and why it looks the way it does, possible concerns about meconium, and a preview of how baby's poop may change as they get older. So, let's get down to business and learn about the number one time baby goes "number two."

What is meconium?

Meconium is the first bowel movement, or poop, that a newborn passes. Your baby will usually pass it 24 to 48 hours after birth.

It is usually black or greenish-black, tarlike, and very sticky. It may be extremely hard to wipe off baby. And yet, it will have almost no smell at all.

The "why" behind meconium

But why does baby pass this type of bowel movement --- and why does it look and smell the way it does?

While baby's still in the womb, they're taking in amniotic fluid, dead skin cells, and lanugo (a fine hair that covers baby while they're in the womb, but that they shed before birth).

Since they ingest all of these substances in the womb, they have to get them out of their body somehow. So, all these substances form meconium in baby's body, which baby will eventually poop out after they're born. As you've probably figured out, when they're processed, these substances look very different than the poop that results from digesting breastmilk, formula, or solid food!

When baby starts to breastfeed or drink formula, their digestive system needs to make room to process this food. The meconium needs to go first. Baby will poop out the meconium 24 to 48 hours after birth.

Why is meconium nearly odorless, though? It's because baby isn't born with most of the gut bacteria that they'll eventually build up. Those gut bacteria are what gives poop its "stink" --- hardly any bacteria means hardly any smell!

When to be concerned about meconium?

When baby poops out meconium after birth, that's perfectly normal!

But if, for some reason, baby poops out meconium before birth, that's a serious problem. This puts baby at risk for a lung condition called meconium aspiration syndrome.

Meconium aspiration syndrome happens when meconium mixes with amniotic fluid, and baby inhales the mixture during or immediately after birth. It may cause baby to have trouble breathing.

About 12% to 20% of babies experience this, so doctors and nurses know how to treat this condition quickly.

At the time of birth, your doctor will check to see if meconium made the amniotic fluid greenish instead of clear.

If they identify this, they'll use suction to remove the meconium from baby's lungs.

Some babies with meconium aspiration may need a ventilator to help them breathe, or antibiotics in case they develop an infection.

Learn more from Mama Natural about what parents need to know about meconium:

What should baby's "normal" poop look like after meconium?

When baby starts to consume breastmilk or formula, and eventually build up their gut bacteria, their poop will change in appearance.

How to know if poop is normal, or if you should be concerned? Any color of poop that's earthy --- brown, yellow, or greenish --- is considered normal.

Breastfed babies' poop should start out tarry and dark green. Then, it should change to a mustard yellow color, and become softer in consistency. It may appear "seedy."

Formula-fed babies' poop should be tan or darker brown, and appear paste-like. This poop will be firmer and smaller than if baby is exclusively breastfed.

When to be concerned about baby's poop?

If baby's poop is red, black, or white, or if there is mucus or blood in the poop, this is a cause for concern. Talk to your doctor if you notice this --- or if you're otherwise concerned about baby's poop.

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All health-related content on this website is for informational purposes only and does not create a doctor-patient relationship. Always seek the advice of your own pediatrician in connection with any questions regarding your baby’s health.

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