Meconium: Your Baby’s First Bowel Movement

The first few hours and days after your baby’s birth can be a magical time, as you finally get to hold and gaze at your newborn after so many months of waiting.

Of course, not every moment is idyllic. Some aspects of parenting are a little messier and, for most people, poop falls firmly into this category! Still, even the messy moments are an important part of the great parenthood adventure ahead.

Meconium is a kind of poop—it’s essentially your baby’s first few poops. Read on to find out precisely what meconium is, where it comes from, and how to deal with it.

What Is Meconium?

In a nutshell, meconium is your baby’s first poop. Meconium is a nearly odorless, greenish-black, gooey substance that’s passed during your baby’s first few bowel movements, often during the first 24 hours after his birth. It looks and smells very different from the regular poop you’ll be finding in your little one’s diapers later on.

What Is Meconium Made Of?

You may be wondering why your newborn even needs to poop at this point, given that he's hardly had a meal yet.

Well, from as early as about week 13 of your pregnancy, your little one started sipping the amniotic fluid surrounding him in the womb.

Practicing these swallowing motions helped his digestive system to develop in preparation for life outside the womb.

A lot of this fluid was passed out again as urine, but some—along with a bunch of skin cells, lanugo hairs shed by your baby, and various other particles floating around in the amniotic fluid—remained in your little one’s intestines.

All these ingredients built up inside your little one’s bowel to make the gooey, tar-like substance that is meconium, which may soon be gracing the inside of your baby’s diaper.

How to Deal With Meconium

Your baby’s first poop comes soon after she’s born, usually within the first 24 hours. This might be before or after the first diaper goes on, so depending on the timing of that first bowel movement you may get a closer look than you bargained for!

Gentle baby wipes can help clean up your baby, and after making sure she’s wearing a absorbent diaper, you're all set.

Meconium has a tendency to stick to things, so—no matter how careful you are—you might get a little on your clothes or your little one’s first bodysuits, especially if you’re still getting the hang of how to diaper your baby.

Although it might not happen for a while yet, experiencing that first blowout is a rite of passage for many new parents.

To avoid leaks, it’s important to make sure your little one’s diapers are a snug fit. If you’re not sure what size of diaper is best for your baby, try using our handy diaper sizing chart.

These are just the first of many diaper changes you’ll be making, so turn those diapers into gifts, discounts, and coupons with the Pampers Rewards app.

When Will Your Baby’s Regular Stools Start?

It can take a few days for the meconium to pass out of your baby’s system. You’ll know when this happens, because your little one’s poop will turn from black to a yellowy green colour.

If you breastfeed your baby, her regular stools will eventually take on the consistency and colour of a light mustard. If you use formula, her regular stools could turn a darker shade of yellow, or tan.

When to Contact Your Healthcare Provider

Meconium is usually harmless, if a little messy sometimes. However, on rare occasions it can cause complications, so it’s best to be aware of these just in case. Here are some examples of when to call your baby’s healthcare provider:

  • If your baby doesn’t poop in the first 24 hours after being born, chances are this is just due to a meconium plug, which is just a bit of poop that has got stuck, but it’s important to rule out a very rare complication known as meconium ileus (which occurs when the meconium is too thick to pass), as this could a sign of a more serious underlying condition.

  • If you see a stool with traces of red, it might just be some blood swallowed during delivery, or your nipples might have bled while he was breastfeeding—but it’s still important to have it checked out, just to be on the safe side.

  • If you ever notice that your little one’s poop is white or clay-coloured, tell your healthcare provider immediately so he can investigate the cause, and rule out any rare conditions that might need urgent treatment.

Meconium Aspiration Syndrome

Sometimes newborns start their first bowel movement during the delivery or during the last weeks of the pregnancy. This means some of the meconium ends up in the amniotic fluid, which is known as “meconium staining” of the fluid.

Rarely, your baby may inhale some of the meconium-stained amniotic fluid, leading to a potentially serious complication known as meconium aspiration syndrome (MAS), when meconium gets into the lungs.

Your healthcare team will be looking out carefully for any signs of this, and they know exactly what to do to make sure that your baby gets prompt and effective treatment and to prevent or minimize any long-term effects.

Most cases of meconium aspiration syndrome are not serious, and if it happens to your little one you can rest assured that your newborn will be in good hands.


Meconium builds up in your baby’s intestines as he swallows the amniotic fluid inside your womb.

Before getting pregnant, you probably never thought that one day you’d be getting so excited about something like poop, but now the meconium lining those first few diapers is a reassuring sign that your little one’s digestive system is raring to go. You’ll treasure all these little firsts, even the gooey ones!

How We Wrote this Article

The information in this article is based on the expert advice found in trusted medical and government sources, such as the American Academy of Pediatrics and the American College of Obstetricians and Gynecologists. You can find a full list of sources used for this article below. The content on this page should not replace professional medical advice. Always consult medical professionals for full diagnosis and treatment.

How many diapers has your baby used?

Swipe to select your baby's age:

Please select your baby's age:

  • 1 monthMONTH
  • 2 monthsMONTHS
  • 3 monthsMONTHS
  • 4 monthsMONTHS
  • 5 monthsMONTHS
  • 6 monthsMONTHS
  • 7 monthsMONTHS
  • 8 monthsMONTHS
  • 9 monthsMONTHS
  • 10 monthsMONTHS
  • 11 monthsMONTHS
  • 12 monthsMONTHS