Meconium Aspiration Syndrome in the Newborn

Baby in uterus (womb) with head turned to side showing trachea (windpipe) and lungs. Meconium is in fluid inside womb. Arrows show meconium going through nose and mouth into lungs.Meconium is the first stool that a baby passes. This may occur before, during, or after birth. Stress may cause the baby to pass meconium before birth. Meconium then floats in the fluid in the womb. It can get into the baby’s nose and mouth. It can even get into the baby’s lungs, especially when the baby takes the first breath. There, the meconium can cause lung irritation and breathing problems. This is known as meconium aspiration syndrome (“aspiration” means “inhaling something that isn’t air”). Depending on how much meconium is inhaled, the problem can range from mild to very severe.

What is the problem?

When meconium gets into the baby’s lungs, the airways (bronchial tubes) inside the lungs become inflamed (red and swollen). This makes breathing harder. Meconium can also get stuck inside the air sacs (alveoli) at the ends of the airways. This makes it harder for the baby to get enough oxygen. Meconium in the airways may also prevent air from leaving the lungs. This can cause the lungs to overinflate (fill with too much air) and lead to problems such as pneumothorax (a collapsed lung).

How is it treated?

Mild cases may not require treatment. In more severe cases, respiratory (breathing) support is needed. This could include:

  • Supplemental oxygen. It may be provided through cannulas (soft tubes inserted into the baby’s nostrils) or through a plastic hood placed over the baby’s head.

  • CPAP (continuous positive airway pressure). This machine provides continuous air flow into the baby’s airways. It helps hold open the airways and clear fluid. The air is blown through a mask that goes over the baby’s nose or through cannulas. CPAP may be used with or without supplemental oxygen.

  • A ventilator. This machine helps the baby breathe by sending air directly into the lungs through an endotracheal tube (ETT). An ETT is inserted through the mouth or nose and into the windpipe.

  • Nitric oxide. This special gas makes the blood vessels in the lungs become larger or wider. This increases blood flow to the lungs and makes it easier for the baby to get oxygen. Nitric oxide is given to the baby on a ventilator.

  • A lung-bypass machine known as ECMO (extracorporeal membrane oxygenation). This machine does all the work for the baby’s lungs until the lungs heal.

What are the long-term effects?

How your baby does will depend on how severe the syndrome is. Some babies recover completely, with no lasting effects. Others may take a long time to recover and have lasting lung damage. If the baby goes without oxygen for too long, this can lead to problems in other parts of the body. Talk with the healthcare provider about how your baby is likely to progress.