Meconium Aspiration Syndrome (MAS)

Meconium is the first poop of your baby. Babies usually pass this in the first hours or days of their life. In some cases, babies may pass meconium while they are still in your uterus, resulting in meconium-stained liquor. Meconium aspiration syndrome (MAS) occurs in 5-10% of births, when a newborn has difficulty breathing because he/she has inhaled some meconium into the lungs. This can clog and irritate the airways or injure the lungs. 

Why does MAS happen?

This happens when baby is stressed and takes in some meconium into the lungs while still in the uterus, or shortly after delivery when he/she starts breathing. Risk factors of baby passing meconium into the water bag while still in the uterus include:

• Labour has been long and stressful
• Past due date 
• Small baby
• Low amniotic fluid in water bag (oligohydramnios)
• Medical conditions e.g. pre-eclampsia

What is the treatment for MAS?

Most of the time, suctioning of baby’s mouth and nose to clear meconium, oxygen supplementation and observation is sufficient for babies delivered in meconium -stained liquor. Other treatment may include:

• Antibiotics 
• Warmer 
• Observation/monitoring in special care nursery
• Breathing help for baby 

In general, most babies with MAS recover well with no long-term issues. Those with breathing problems generally resolve in a few days. Rarely, a baby with MAS may require breathing machines to help with their lungs – lack of oxygen can result in lung or brain damage, or even death.