Health Encyclopedia

Meconium Aspiration

What is meconium aspiration?

Meconium is your baby’s first stools. Sometimes a baby will pass stool into the amniotic fluid. It can get into your baby’s nose and mouth. Meconium aspiration is when your baby inhales amniotic fluid containing meconium when he or she begins to breathe.

What causes meconium aspiration?

Doctors don’t fully understand why babies release stool before they are born. It may be a natural event, or it may be caused by stress. 

Meconium aspiration only happens in about 10 percent of births. It is most common in babies born at term (37 to 41 weeks) or post-term (after 42 weeks).

Why is meconium aspiration a concern?

When your baby takes his or her first breaths at delivery, meconium particles can enter the airway and can be inhaled (aspirated) deep into the lungs. The meconium may stick to the airways or alveoli, making it hard for your baby to take in oxygen. It may also trap air in your baby’s lungs.

It can also cause an infection, like pneumonia. Although most babies generally get better within a few days, severe meconium aspiration, and the breathing problems it causes, may lead to death in a small number of babies.

What are the symptoms of meconium aspiration?

Meconium gives the amniotic fluid a greenish color. This is called meconium staining. If meconium has been in the amniotic fluid for a long time, your baby may have yellowed skin and nails.

Your baby may also have symptoms like:

  • Rapid breathing

  • Retractions (pulling in of the chest wall)

  • Grunting sounds with breathing

  • Bluish skin color (cyanosis)

  • An enlarged or bloated chest because of trapped air

The symptoms of meconium aspiration may resemble other conditions or medical problems. Always see your baby's health care provider for a diagnosis.

How is meconium aspiration diagnosed?

Your health care provider will check the amniotic fluid for meconium. Your provider may also recommend a chest X-ray to check for problems in your baby’s lungs.

Treatment for meconium aspiration

Your baby’s health care provider will likely recommend treatment for meconium aspiration based on:

  • The amount and thickness of the meconium

  • How long your baby was exposed to the meconium

  • How well your baby can breathe

At delivery, treatment may include:

  • Suctioning of the upper airways, including the nose, mouth, and throat

  • Suctioning of the lower airways through an endotracheal tube (ET) placed in the windpipe, although this is not recommended routinely unless it is necessary.

  • Supplemental oxygen given by face mask or mechanical ventilator

Prevention of meconium aspiration

It’s important to know if your baby has been exposed to meconium to prevent severe aspiration problems. A procedure called amnioinfusion may be used during labor if you have meconium-stained amniotic fluid. During this procedure, your health care provider inserts a small tube into your uterus through the vagina. Sterile fluid is put into the womb through the tube to help thin the thick meconium.

Medical Reviewers:

  • MMI board-certified, academically-affiliated clinician
  • Trevino, Heather M., BSN, RNC