National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Meconium aspiration syndrome



My son has suffered meconium aspiration syndrome. What causes this condition?

The following information may help to address your question:


What is meconium aspiration syndrome?

Meconium aspiration syndrome is a serious condition in which a newborn breathes a mixture of meconium and amniotic fluid into the lungs around the time of delivery. This can cause breathing difficulties due to swelling (inflammation) in the baby's lungs after birth. Treatment may include suctioning the newborn's mouth as soon as the head emerges during delivery, deep suctioning of the windpipe, antibiotics to treat infection, oxygen to keep blood levels normal, and radiant heat to maintain body temperature. In severe cases, the baby may need assistance breathing (ventilator).[1]
Last updated: 1/12/2012

What causes meconium aspiration syndrome?

Meconium is the term used for the early feces passed by a newborn soon after birth. In some cases, the baby passes the meconium while still inside the uterus. This most often happens when babies are under stress because they are not getting enough blood and oxygen. Once the meconium has passed into the surrounding amniotic fluid, the baby may breathe meconium into the lungs. This may happen while the baby is still in the uterus or immediately following birth. Some of the factors that may cause stress on the baby before birth include:[1]

  • Decreased oxygen immediately before or during the birthing process 
  • Difficult or lengthy labor and delivery 
  • Delivery that occurs past the due date
  • High blood pressure in the pregnant mother
  • Diabetes in the pregnant mother
Last updated: 1/12/2012

We hope this information is helpful. We strongly recommend you discuss this information with your doctor. If you still have questions, please contact us.

Warm regards,
GARD Information Specialist

Please see our Disclaimer.


  1. Lee KG. Meconium aspiration syndrome. MedlinePlus. 2009; http://www.nlm.nih.gov/medlineplus/ency/article/001596.htm. Accessed 1/12/2012.