Meconium: Your Baby’s First Poop

Meconium is a newborn’s first poo: a thick, sticky, dark green-black substance made from what the baby has swallowed in the womb (such as amniotic fluid, mucus and skin cells). It usually appears in the first 24–48 hours after birth and is a key sign that the gut is working and feeding is starting to take effect.  

• Normal: passes within 1–2 days, then stools turn lighter and looser  

• Watch for: no stool after 48 hours, very pale stools, or signs of illness  

• In labour: meconium in the waters can sometimes signal fetal stress and needs monitoring  

Next, we’ll look at what’s normal, what changes to expect, and when to seek medical advice.

What Is Meconium?

Meconium is your baby’s very first poo - thick, sticky and dark coloured.

Put simply, meconium is your baby’s 'first poo'. To be more precise, it’s an almost odourless, blackish-green sticky gloop that usually comes out in those first nappy changes, often within the first 24 to 48 hours after they’re born.

Meconium stool looks and smells completely different from what you’ll see in nappies as your baby gets older, which will usually be a lighter colour with a less gooey consistency.

Typical Meconium Colour and Texture

The dark shade and tar-like stickiness is what sets meconium apart from later poos.

Unlike regular baby poo that’s much lighter in colour, meconium is deep green, almost black, and really sticky, almost like tar.

What’s Meconium Made Of?

Wondering what is in meconium when your little one hasn’t even had their first feed yet?

Well, at around 14 weeks of your pregnancy, or perhaps even a little earlier, your little one started sipping the amniotic fluid that surrounded them in the amniotic sac.

Practising these swallowing motions helped your foetus’s digestive system to develop in preparation for life outside the uterus.

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

All these ingredients built up inside their bowel to make the gooey, tar-like poo known as meconium.

Is Meconium Sterile?

You might wonder if meconium is actually germ-free. Meconium forms before birth and is generally considered sterile at that point, meaning it’s usually free of bacteria.

Researchers are still learning more about the meconium microbiome, so the jury’s still out on whether there is bacteria present. For now, experts agree meconium is largely sterile—though there’s more to learn about when babies pick up their first microbes.

How Long Does Meconium Last?

So, how long does meconium last before your baby’s nappies go from blackish-green to yellowy? It usually takes a couple of days for the meconium to clear out. You’ll notice the meconium colour change, from almost black to a more yellowy-green as feeding gets going.

If you’re breastfeeding, your baby’s poo will likely change to a pale mustard yellow with a runny consistency. On formula, your baby's poo might look darker, browner, and have a firmer consistency than a breastfed baby poo. You might even notice a greenish poo if your baby is formula-feeding.

FEATURED PRODUCT

Pampers® Premium Protection

What Happens If Your Baby Doesn’t Pass Meconium?

Most babies pass meconium in the first 24–48 hours. If not, the general rule is to let your healthcare provider know.

Sometimes, not passing meconium can mean a blockage in your baby’s gut. A rare cause is meconium ileus, where the meconium’s so sticky it clogs things up. Your doctor will look for things like a swollen tummy or vomiting and might recommend more checks if needed.

If your baby still hasn’t had a meconium stool after two days, check in for some advice on what to do next.

Meconium Ileus and Other Possible Causes

If your baby’s meconium has not passed and is delayed, it could be down to certain conditions. Meconium ileus is one: it is thick meconium blocking the intestines and sometimes linked to cystic fibrosis, so doctors might recommend extra tests.

There’s also the meconium plug, which is a small lump temporarily blocking things up and often clears with a little help from the healthcare team.

How to Deal With Meconium: Cleaning and Nappy Changing

Meconium is really sticky, so you’ll want to change nappies often and clean meconium carefully each time.

Meconium – your baby’s first poo – comes soon after your baby is born, usually within the first 24 hours. This might happen before or after the first nappy goes on, so depending on the timing of that first bowel movement, you may get a closer look than you bargained for!

You can use gentle baby wipes to help clean up your baby. Once you’ve done that, a comfortable, absorbent nappy can go on.

Wondering how to clean meconium? Gentle baby wipes, like Pampers Sensitive, work well. Pop on a fresh, comfy nappy after. Want help picking the right one? Take our easy quiz to find the perfect nappy for your baby.

Meconium tends to stick to things, so – no matter how careful you are – you might get some on your clothes or your newborn baby’s first bodysuits, especially if you’re still getting the hang of changing your baby’s nappy.

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

To help avoid leaks and blowouts, it’s important to make sure your baby’s nappies are a snug fit. If you’re not sure what size of nappy is best for your baby, our nappy size guide can help.

What Is Meconium Staining?

Meconium staining is when your baby passes poo before or during birth, which colours the amniotic fluid greeny or brownish. This is known as meconium-stained fluid.

So, do babies poo in the womb? Sometimes, yes, often in the later weeks or during labour.

Even though it sounds worrying, meconium staining doesn’t always mean trouble. Your healthcare team knows what to look for and will keep an eye out. Occasionally, babies breathe in the stained fluid, which is why close monitoring at birth is important.

If your waters break and you notice green or brown fluid, get in touch with your doctor or midwife straight away so they can check for a safe delivery.

Meconium Aspiration Syndrome (MAS) Guidelines

If meconium ends up in the baby’s lungs, your medical team will closely monitor and choose the best course of treatment.

Rarely (only 2 out of every 1000 babies are affected by this), your baby may inhale some of the meconium-stained amniotic fluid, leading to a potentially serious complication called meconium aspiration syndrome (MAS), which is when meconium gets into the lungs.

Your doctor or midwife will be watching for any signs of this, and they know exactly what to do to make sure that your baby gets prompt and effective treatment, to prevent or minimise any long-term effects.

How Serious Is Inhaling Meconium?

Most cases of meconium aspiration syndrome are not serious, and early treatment usually prevents complications. If it does happen to your baby, you can rest assured that your little one will be in good hands.

Meconium Aspiration Syndrome Symptoms

Common signs and symptoms of meconium aspiration syndrome are usually noticed soon after birth, like:

• Fast or hard breathing

• Grunting while breathing

• Bluish or greyish skin (low oxygen)

• Limpness, being floppy

• Low Apgar scores.

Your healthcare team will be watching for these to decide if it’s MAS or something else.

Meconium Aspiration Syndrome Treatment

How MAS is managed depends on how poorly your baby is. Options include:

• Careful monitoring of breathing and oxygen

• Extra oxygen or breathing help

• Suctioning out the airways if needed

• For more serious cases, machines help breathing in NICU.

Most babies do really well, and care is all about helping them recover and preventing complications.

When to Contact Your Healthcare Provider

Get in touch with your provider if meconium stools look odd, your baby seems ill (fever, vomiting, very sleepy), or you have any concerns.

Meconium is usually nothing more than messy. But, in rare cases, it can lead to problems, so it’s handy to be aware just in case.

Contact your healthcare team if:

• Your baby hasn’t had a poo in the first 24 hours. It could be a plug (just some stuck meconium), but rare problems like meconium ileus should be ruled out, as it could mean a blockage or underlying issue.

• There’s red in the nappy. It might just be blood swallowed at birth, or if your nipples have bled from feeding, but it’s always best to have it checked.

• Poo is white or clay-coloured. Let your healthcare team know straight away, as this can mean there’s a rare but urgent condition needing help fast.

Your healthcare team is always there to offer reassurance. No worry is ever too small -consult them if you have any concerns or questions.

If you’re looking for more guidance on your baby’s first days, you can explore our Go-To Pregnancy Guide for helpful tips and support.

The Bottom Line

Meconium is completely normal, and a great sign your baby’s digestive system is working. If you have any concerns, your healthcare team will guide and reassure you.

Let’s be honest: before your little one arrived, you probably never thought you’d be so interested in baby meconium poo! But every first, even messy ones, is part of the magical journey. Treasure them all!

Want to save on nappies? Download the Pampers Club App for exclusive savings on Pampers nappies!