What is meconium aspiration syndrome?

Meconium is the first feces, or stool, of the newborn. Meconium aspiration syndrome occurs when a newborn breathes a mixture of meconium and amniotic fluid into the lungs around the time of delivery. Meconium aspiration syndrome, a leading cause of severe illness and death in the newborn, occurs in about 5 percent to 10 percent of births. It typically occurs when the fetus is stressed during labor, especially when the infant is past its due date.

Symptoms

• Bluish skin color in the infant
• Breathing problems
• Dark, greenish staining or streaking of the amniotic fluid or the obvious presence of meconium in the amniotic fluid
• Limpness in infant at birth

Diagnosis

• Before birth, the fetal monitor may show a slow heart rate.
• At birth, meconium can be seen in the amniotic fluid. The most accurate test to check for possible meconium aspiration involves looking for meconium staining on the vocal cords with a laryngoscope.
• Abnormal breath sounds, especially coarse, crackly sounds, are heard through a stethoscope.
• A blood gas analysis shows low blood acidity, decreased oxygen and increased carbon dioxide.
• A chest X-ray may show patchy or streaky areas on the lungs.

Treatment

The newborn's mouth should be suctioned as soon as the head can be seen during delivery. Further treatment is necessary if there is thick meconium staining and fetal distress. The infant may be placed in the special care nursery or newborn intensive care unit. Other treatments may include:

• Antibiotics to treat infection
• Breathing machine to keep the lungs inflated
• Use of a warmer to maintain body temperature
• Tapping on the chest to loosen secretions

If there have been no signs of fetal distress during pregnancy and the baby is a vigorous full-term newborn, experts recommend against deep suctioning of the windpipe for fear of causing a certain type of pneumonia.

Prognosis

In most cases, the outlook is excellent and there are no bad side effects. In more severe cases, breathing problems may occur, though they generally go away in two to four days. However, rapid breathing may persist for days. An infant with severe aspiration who requires a breathing machine may have a more guarded outcome. Lack of oxygen in the uterus or from complications of meconium aspiration may lead to brain damage. Meconium aspiration rarely leads to permanent lung damage.