Meconium aspiration syndrome (MAS)
Meconium is the name of the stool that accumulates in the baby's intestines while it is in the womb.
If a baby, during a difficult birth, becomes very stressed, for example due to lack of oxygen, it can cause the baby to defecate in the amniotic fluid and even to try to breathe before birth. It can cause the baby to aspirate amniotic fluid mixed with faecal material into its lungs, that is, aspirate meconium.
This triggers an inflammatory reaction, a kind of chemical pneumonia. Sometimes the baby has difficulty initiating breathing immediately after birth, sometimes the symptoms appear during the first few hours of life with laboured breathing, increasing demand for oxygen and often rapid deterioration. An X-ray of the lungs will show a typical speckled pattern.
The treatment is respiratory support with oxygen, CPAP and a ventilator in more severe cases. Antibiotics are given because there is a risk of a bacterial infection.
Meconium aspiration syndrome (MAS) often leads to high blood pressure in the lungs, pulmonary hypertension (PPHN, see separate section). If the baby receives neonatal intensive care, the baby will improve within 1-2 weeks.
Text: Kajsa Bohlin Blennow