Meconium Aspiration Syndrome (MAS):Best article 2025

Meconium Aspiration Syndrome (MAS) is a serious condition that can occur when a newborn inhales meconium into the lungs during the perinatal period.

1. Pathogenesis of MAS

MAS occurs when meconium, which is normally passed after birth, is released into the amniotic fluid before or during labor. This may happen when there is fetal distress, hypoxia, or other stresses on the fetus that lead to peristalsis and the expulsion of meconium into the amniotic fluid. The pathogenesis involves:

• Aspiration: The fetus may inhale meconium into the airways during or after delivery. The risk is higher in cases of meconium-stained amniotic fluid.
• Airway Obstruction: Meconium can cause mechanical obstruction in the airways, leading to respiratory distress.
• Chemical Pneumonitis: The meconium may also cause chemical injury to the lungs, leading to inflammation and further complications such as pulmonary hypertension and surfactant dysfunction.
• Infection: Meconium may be contaminated with bacteria, leading to an increased risk of infection, particularly pneumonia.

2. Management of MAS

The management of MAS focuses on preventing and treating respiratory complications and ensuring the neonate’s stability:

• Initial Resuscitation: Neonates born through meconium-stained amniotic fluid should be assessed immediately after birth. If the baby is not vigorous (i.e., not crying, not moving, or not breathing), the airway should be cleared of meconium immediately with suctioning. This should be done with a sterile suction device, and the trachea can be suctioned with a flexible catheter if necessary.
• Oxygen Therapy and Ventilation: Oxygen should be administered to neonates with respiratory distress. Mechanical ventilation may be required in severe cases, and surfactant therapy may be indicated if surfactant dysfunction is suspected.
• Antibiotics: In cases where infection is suspected, particularly if the meconium is thick or there are signs of infection, broad-spectrum antibiotics may be started.
• Supportive Care: In severe cases, management may involve intensive care, including respiratory support (e.g., positive pressure ventilation or ECMO if the situation is severe) and monitoring for pulmonary hypertension.

3. Delivery Room Management of a Term Baby Born Through Meconium-Stained Liquor

In the delivery room, the management of a term baby born through meconium-stained liquor requires prompt action to minimize the risks of MAS:

• Assessment of Neonatal Status: The first step is to assess whether the baby is vigorous or not. A vigorous baby (crying, moving, breathing) does not require immediate suctioning of the airways.
• If the Baby is Non-Vigorous: If the baby is not breathing or not crying (indicating respiratory distress), immediate suctioning of the mouth, nose, and potentially the trachea should be performed. Suctioning should be done before any stimulation or resuscitation to avoid further aspiration of meconium.
• Oxygen Administration: If the baby is having trouble breathing after clearing the airway, oxygen should be administered. If necessary, ventilation should be started to support the infant’s breathing.
• Intubation and Suctioning: In cases of significant meconium aspiration, intubation and deep suctioning of the trachea with a catheter may be necessary to clear the airways. This should be done quickly and effectively to reduce the risk of aspiration pneumonia and other complications.
• Monitoring: Close monitoring in a neonatal intensive care unit (NICU) setting is recommended for babies with moderate or severe MAS. Continuous monitoring of oxygen levels, ventilation, and other vital signs is essential.

In conclusion, early recognition and management of MAS are critical for reducing the risks of long-term complications such as pulmonary hypertension, hypoxemia, and infection.