Meconium Aspiration Syndrome: Symptoms, Causes, and Treatments


Meconium Aspiration Syndrome or MAS is respiratory distress in newborns due to inhalation of meconium. Meconium is your baby's first stool. MAS occurs if your baby inhales the meconium along with the amniotic fluid before, during, or after the delivery. The condition can be present in pre-term, term, and post-term babies. However, MAS mostly occurs in about 27.5% of post-term newborns. Timely management can help your baby get the required respiratory support.


Your doctor will observe the following signs of MAS before or at birth:

  • Blue-tinted skin
  • Difficulty in breathing
  • Dark green stains or streaks of meconium in the amniotic fluid
  • Limpness in the baby
  • Slowed heart rate


Meconium aspiration syndrome is usually seen in post-term newborns. These babies are not delivered on time, which can cause uterine stress. Other causes of MAS include:

  • Long and challenging delivery
  • Birth after the due date
  • The mother has medical conditions like diabetes or high blood pressure
  • Using drugs or smoking during pregnancy
  • Underdevelopment
  • Uterine stress due to low oxygen or some infection


Babies with no other apparent reason for respiratory distress are suspected of Meconium aspiration syndrome. Once your doctor rules out all other possible reasons for respiratory distress, they will confirm MAS with:

  • Foetal monitor: A foetal monitor will show a reduced heart rate before birth.
  • Visible signs: The amniotic fluid at the birth of your baby will have a green tint due to meconium.
  • Laryngoscope: Your doctor will check your baby's throat for meconium staining with a laryngoscope. Aspiration is confirmed if this test is positive.
  • Physical examination: Your baby will make abnormal and crackling sounds while breathing.
  • Chest x-ray: A chest x-ray will show patches or streaks on the lungs.
  • Blood gas test: Your baby's blood gas analysis will show reduced blood acidity (respiratory acidosis). It will also show low oxygen values (hypoxia), and high carbon dioxide values (hypercapnia).

Timely treatment is critical for babies with MAS. Consult an experienced doctor for your baby's safety.


If your doctor is aware of MAS in your case, they should begin the treatment as soon as your baby is born. Active management will avoid any future complications. Your baby will be under medical care in the newborn intensive care unit (NICU) for a few days.

Treatment for MAS requires:

  • Suctioning of mouth as soon as the head is visible
  • Antibiotics for infections
  • Breathing machine for respiratory support. This will keep the baby's lungs inflated.
  • A warmer to keep the body warm
  • Tapping the chest to loosen the secretions

Your doctors may not suction your baby if there are no distress signs and the baby is vigorous. Suctioning can put your baby at risk of fatal infections like pneumonia.


Some moderate to severe complications of MAS include:

  • Airway obstruction
  • Inactivation of surfactant, a fluid that opens up the lungs when a newborn breathes for the first time.
  • Respiratory distress
  • Air leak syndrome
  • Neurodevelopment impairment


Meconium aspiration syndrome affects 10% of term and post-term newborns. It is the leading cause of respiratory distress in infants. Diagnosis, management, and treatment of the condition are critical to reducing mortality rates. Your baby will quickly recover if treated on time.

Request an appointment at Apollo Cradle, Bengaluru - Jayanagar. Call 1860-500-1066 to book an appointment.

1. Can I prevent MAS in my baby?

You must ask your doctor to induce labour if you are past your due date to prevent MAS. You must also alert your doctor if your water breaks and has green streaks in it.

2. What other conditions have similar symptoms to MAS?

A differential diagnosis to rule out the conditions that show similar symptoms as MAS includes:
1. Respiratory distress syndrome
2. Transient tachypnea
3. Infections like sepsis and pneumonia
4. Congenital heart diseases

3. Why is my baby breathing rapidly after the treatment?

Rapid breathing occurs in severe cases and will disappear in a few days.

4. Will my baby have lung damage due to MAS?

Meconium aspiration syndrome does not always result in permanent lung damage.

5. Will my baby have brain damage due to MAS?

Your baby will be at risk of brain damage due to lack of oxygen or other complications due to MAS. This is why it is important to stay alert and inform your doctor if you notice anything unusual.

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