What is Meconium?

Medically Reviewed by Traci C. Johnson, MD on April 23, 2023
3 min read

When your baby is born, you may be given a chart to track your baby’s wet and dirty diapers while you are there. The doctors want to make sure that there are a certain number of each kind of diaper so that they know your baby is properly passing waste through their body and getting rid of it.

A baby’s first poop, called meconium, is known for being dark and thick. Learn more about meconium and what your baby’s poop will look like after the meconium passes. 

When your baby is in the womb, they begin to practice drinking by taking in the amniotic fluid that surrounds them. Then their body processes out the waste, filtering the fluid through the digestive tract. While your baby often passes urine while still in the womb, they won’t poop until after birth.

Your baby’s first poop is called meconium. As your baby begins to breastfeed or drink formula, their body will get rid of the meconium, making room for processing the milk or formula they are drinking. It's expected that the meconium will pass through your baby's system within the first 24 to 48 hours after birth. 

Ideally, your baby's poop will change color and consistency while you are still in the hospital. This change lets doctors know that your baby’s digestive system is working properly. 

Meconium Aspiration. If your baby poops in the womb or during the birthing process, they might develop a dangerous lung condition called meconium aspiration. Babies are at risk for passing meconium before birth if:

  • The mother has preeclampsia
  • The labor or delivery is particularly stressful
  • The mother does drugs like cocaine while pregnant
  • There is a peripartum infection 

Identifying Meconium Aspiration. After you give birth to your baby, your doctor will check the amniotic fluid for streaks of meconium, so they know if your baby is at risk of developing meconium aspiration. Your doctor will also examine your baby to see if they show any signs of the condition, which may include any of the following:

  • Your baby’s skin has a blue appearance
  • Your baby appears to be struggling to breathe, has noisy breathing, is grunting, or is not breathing on their own at all
  • Limp, or no responsiveness at birth

‌Treating Meconium Aspiration. Doctors and nurses may rub your baby with a towel to warm them and encourage their body to start breathing. If they still struggle to breathe or if they have a low heart rate, they may apply an oxygen mask to fill your baby's lungs. Additionally, your baby may need:

  • Placement in a neonatal intensive care unit (NICU) for monitoring
  • Antibiotics in case there might be an infection
  • A ventilator if your baby cannot breathe on their own 
  • IV nutrition if your baby cannot nurse or take a bottle
  • Overhead warmer to maintain your baby's body temperature

Most babies recover from meconium aspiration. Meconium happens in 12% to 20% of all live births, so doctors and medical staff are very familiar with how to treat a baby’s condition quickly.

Once meconium passes, your baby’s poop will change in color, consistency, and smell. Keep in mind that if your baby is primarily breastfed and you occasionally use formula, the color and consistency may change based on how much of each source of food they are receiving. 

Breastfed Baby Poop

The poop of a breastfed baby is very different from that of a formula-fed baby. It is usually softer and yellow in color. You may notice “seeds” in your baby’s diaper, too. A breastfed baby may poop multiple times in a day, but it isn’t unusual for your baby to go 7 to 10 days without pooping. 

Formula-fed Baby Poop

If your baby is fed formula, they may have darker, smellier poop than if they were breastfed. This is normal. Generally speaking, your baby’s diapers will be smellier and firmer than if your baby was breastfed. 

When to be Concerned

Any color of poop that resembles an earth tone is considered healthy and normal. This includes the colors yellow, green, brown, and anything in between.

However, if your baby’s poop is white, red, or black, talk to your baby’s doctor. White poop is a sign that your baby’s liver is not working correctly. Red poop indicates the presence of fresh blood — your baby’s or yours if your nipples are bleeding. Black poop indicates the presence of old blood since blood turns black with age.