Aspiration of the waste products produced by the foetus in the womb. Meconium is the first waste product excreted by a new-born child. It is a greenish-black, viscous, sticky substance which lightens after three days and becomes normal faeces. Aspiration occurs if the baby starts to breathe too soon because it is suffering from oxygen shortage (asphyxia) in the womb. At the same time meconium is discharged, making the amniotic fluid green rather than colourless. Amniotic fluid containing meconium is a danger signal; if it is combined with an irregular heartbeat, labour should be induced rapidly. Symptoms in the new-born child depend on the severity of the asphyxia. Causes of meconium aspiration are to be found in oxygen shortage during labour; in a long or difficult labour, for example, entanglement of the umbilical cord or drugs taken by the mother. Treatment is according to the condition of the baby. In any case the baby should be placed in a warm atmosphere with the head pointing slightly downwards, and the air passages pumped free of mucus, blood and meconium. If the condition is more serious the baby should be admitted to hospital; possible complications are pneumonia and the consequences of asphyxia.