Sometimes — before birth or during labor and delivery — a baby inhales a mixture of amniotic fluid and a substance called meconium into his lungs. This is called meconium aspiration syndrome (MAS), ...

Meconium aspiration syndrome (MAS) remains a serious neonatal respiratory disorder that occurs when newborns inhale meconium‐stained amniotic fluid during delivery. This condition, often associated ...

Meconium is a thick substance that lines a baby’s intestines in the womb. A baby usually passes meconium after birth, but if they pass it early, the amniotic fluid may become meconium-stained.