During the stressful labor, the infant may suffer a lack of oxygen. The inhaled meconium can cause a partial or complete blockage of the airways, causing difficulty breathing and poor gas exchange in the lungs. In addition, it is irritating and causes inflammation in the airways and a type of pneumonia. Meconium staining of the amniotic fluid with possibility of aspiration occurs in approximately 5 percent to 10 percent of births. About one third of the infants with meconium aspiration will require some type of assisted breathing.
Meconium aspiration is a leading cause of severe illness and death in the newborn.
The infant may have a low Apgar score. Direct visualization of the vocal cords for meconium staining with a laryngoscope in the delivery room is the most accurate evaluation for possible meconium aspiration . The newborn's mouth should be suctioned as soon as the head is delivered. Further intervention is necessary if there is thick meconium staining and fetal distress. A tube is placed in the infant's trachea and suction is applied as the endotracheal tube is withdrawn.