Meconium aspiration syndrome occurs when the baby inhales meconium. Meconium is the baby’s first bowel movement, made up of amniotic fluid and cells that the baby swallowed while in the womb. Stress can cause the baby to release meconium while still in the uterus or during delivery and then gasp it in. Babies who aspirate meconium into their airways and lungs may suffer from meconium aspiration syndrome.
Meconium aspiration syndrome makes it difficult for the baby to breathe as the meconium blocks the baby’s airways and damages the lungs. In severe cases, part of the lungs may become hyperinflated and rupture, causing the lung to collapse.
Treatment for meconium aspiration syndrome varies depending on the severity of the case and may involve suction, oxygen, a ventilator, or extracorporeal membrane oxygenation. Your baby may also need treatment for secondary effects of meconium aspiration, such as infection or lung collapse.
When meconium is released, it stains the amniotic fluid and turns it green. Once your water breaks, your doctor will know that the baby has released meconium and may be at risk for meconium aspiration syndrome. She will want a team of nurses and doctors on hand during the delivery to handle any potential consequences of meconium aspiration.
Only a small fraction of babies who release meconium prematurely will actually aspirate it. Most babies who release meconium are completely healthy and have no meconium in their lungs or airways.
Your doctor will use a small bulb to suction out the baby’s nose and mouth as in any delivery and perform an Apgar test to ensure that the baby’s breathing, heart rate, reflexes, and muscle tone are normal. If they are, there is no need for any further treatment.
If there is meconium in the amniotic fluid and the baby is not crying normally or is struggling to breathe, your doctor will need to administer some treatment. In most cases, the baby only aspirates a small amount of meconium. Your doctor will suction out the baby’s mouth and nose and use a tube to suction out the trachea as well. That removes the meconium from the baby’s airways so the baby can breathe easily and to avoid the risk of hyperinflation and collapse of the lung.
If suctioning out the baby’s airways is not enough and the baby doesn’t start to breathe and cry normally, your baby may need a little more help. The next step is to give the baby more oxygen. Your doctor may use a face mask or a special hood to deliver oxygen to the baby. If the baby’s oxygen levels are still too low, the baby may need oxygen delivered under pressure, either by squeezing a pump attached to a face mask or by use of a CPAP (continuous positive airway pressure) machine.
If the baby still isn’t getting enough oxygen, your doctor may decide to “intubate,” or put the baby on a ventilator. Intubation involves placing a tube through the baby’s mouth into the airways. That tube is connected to the ventilator, which pushes air into the baby’s lungs so they can fully inflate and get enough oxygen into the bloodstream. The ventilator does the work of breathing, allowing the baby’s lungs to rest and heal.
Before intubation and while on the ventilator, your baby may be sedated to prevent distress. Ventilators have their own risks and will only be used in very serious cases.
Extracorporeal Membrane Oxygenation
In the most extreme cases of meconium aspiration syndrome, even a ventilator may not be enough. The next step in treatment is extracorporeal membrane oxygenation (ECMO). ECMO means the baby is placed on a heart-lung bypass machine. The machine acts like an artificial lung. The baby’s blood is pumped through the machine, oxygenated, and then pumped back into the baby’s body. This allows the heart and lungs to rest and heal while keeping healthy levels of oxygen in the baby’s blood.
Meconium aspiration syndrome alone is rarely severe enough to require ECMO. This treatment is typically needed where the baby also has persistent pulmonary hypertension of the newborn (PPHN). PPHN refers to a hardening and constriction of the arteries that take blood to the lungs. PPHN makes it hard for the baby to get enough oxygen and is typically caused by stress in the womb. Babies with PPHN almost always also release meconium prematurely, so the two conditions often occur together.
ECMO is even more serious than use of a ventilator and, like a ventilator, has its own risks. So, ECMO is reserved for very serious cases of respiratory distress.
Meconium aspiration syndrome may cause secondary side effects such as lung hyperinflation and collapse and chemical pneumonitis. Your baby may require treatment for one of these secondary effects.
Lung Hyperinflation and Collapse
Meconium can act as a ball valve in the baby’s airways, letting air in but not out. That causes the baby’s lungs to hyperinflate. In some cases, part of a lung may actually rupture and leak air out into the cavity surrounding the lungs. If enough air leaks outside of the lungs, the pressure of that air can cause part of the lung to collapse. Depending on the location of the collapse, it may be called a pneumopericardium, a pneumothorax, or a pneumomediastinum.
If the collapse is relatively small, it may go away on its own. Larger collapses may require treatment to remove the air around the lung. That air is usually sucked out by a small tube or needle inserted into the air pocket. This relieves the pressure on the lung and allows it to reinflate.
If removing the air pocket isn’t enough, your baby may require surgery to find and seal the leak.
Pneumonitis refers to inflammation of the lung tissue. Meconium contains a number of proteins and enzymes that can irritate the lung tissue and cause it to swell. Your baby may need corticosteroids to reduce the inflammation.
Tissue that is already inflamed is vulnerable to infection. That means babies with meconium aspiration syndrome are at higher risk for infection for the first part of their lives. Bacterial respiratory infections may be treated with antibiotics. Viral respiratory infections are much harder to treat; doctors are typically limited to managing the symptoms while the infection runs its course.
Most babies with meconium aspiration syndrome recover completely and require no special long-term care. Some babies may be at higher risk for infection for the first few years of life.
Very severe cases of meconium aspiration syndrome may cause permanent damage to the baby’s lungs. In addition, side effects of drastic treatments like ventilators and ECMO may result in permanent damage requiring long-term care. Finally, remember that meconium aspiration syndrome deprives the baby of oxygen. Oxygen deprivation can cause permanent brain damage.