Meconium is the first thick and sticky bowel movement, feces, or stool that is normally stored in the infant’s intestines until after birth. Sometimes, the meconium is released into the amniotic fluid prior to birth or during labor. This usually happens when the baby is under stress or there is a decrease in the amount of blood and oxygen reaching the fetus.
The most obvious sign that meconium has been passed before the baby is born is a green or yellow color of the amniotic fluid. Once a doctor or nurse midwife is aware of meconium stained fluid, they should take the appropriate precautions to prevent a baby from breathing in the meconium after birth.
If the meconium is inhaled into the lungs, it can partially or completely block the baby’s airway. As the baby tries to breath, the meconium can be pushed further down into the lungs making it even more difficult to breath. If the baby inhales the contaminated fluid into its lungs, it is usually referred to as meconium aspiration, meconium aspiration syndrome or MAS.
MAS can present with varying degrees of severity from mild breathing problems to respiratory failure and death. Severe meconium aspiration can lead to a lack of oxygen to the baby’s brain, hypoxic ischemic encephalopathy, HIE, permanent brain damage and cerebral palsy.