Meconium is a completely normal part of your baby’s first days. It is their very first stool, which is usually passed after birth. But, in some cases, babies release meconium while still in the womb. If this mixes with amniotic fluid and your baby breathes it in, it can cause meconium aspiration syndrome (MAS). As a parent, hearing this can feel frightening. But the good news is that with timely treatment, most babies do very well. Understanding what MAS is, why it happens, and how doctors manage it can help you feel reassured.



What is meconium?Meconium is the first poop that the baby passes after being born. It is thicker, darker, and stickier than the usual poop. It has a greenish-black, tar-like appearance and builds up in the baby’s intestine from the amniotic fluid they swallow throughout the pregnancy.



What is meconium aspiration syndrome?Meconium aspiration syndrome (MAS) happens when your baby breathes in meconium (the first poop after birth), either during labour or delivery. If this meconium gets into the baby’s lungs before or during birth, it may block or irritate the airways and cause breathing problems. However, with early treatment and care, most babies recover well.



What Causes Meconium Aspiration Syndrome (MAS)?

Meconium aspiration happens when your baby breathes in amniotic fluid mixed with meconium before, during, or right after birth. The reason behind your baby passing meconium is stress. When babies are under stress, they may take deep and forceful gasps. These deep gasps can pull meconium into their lungs, making it hard for them to breathe.



Your baby is more likely to pass meconium into the amniotic fluid if:

• The delivery is long or difficult
• The pregnancy goes past the due date
• Your baby didn’t grow well before birth
• You smoked or used drugs during pregnancy
• You have health conditions like diabetes or high blood pressure
• There is low oxygen supply or an infection before delivery

What Are the Symptoms of Meconium Aspiration Syndrome (MAS)?Doctors may suspect meconium aspiration before or during birth if the amniotic fluid looks greenish or stained with meconium. After delivery, babies who have inhaled meconium often show certain warning signs.



The common symptoms indicating meconium aspiration include the following:

• Trouble breathing or fast breathing
• Chest retractions (the chest sinking in with each breath)
• Grunting sounds while breathing
• Limp or weak muscle tone at birth
• Bluish skin colour (cyanosis) due to low oxygen
• Slow heart rate

How Is Meconium Aspiration Syndrome Diagnosed?If meconium is seen in the amniotic fluid, your doctor will closely monitor your baby after birth. Not all babies who pass meconium will breathe it in, but doctors observe for any signs of distress.



After birth, doctors usually check the baby for:

• Breathing problems or a low Apgar score
• Abnormal breath sounds (often coarse or crackly) heard through a stethoscope

Tests used to diagnose MAS include:

• Chest X-ray: Shows patchy or streaky areas in the lungs, sometimes with overinflation or collapse of parts of the lungs.
• Blood gas analysis: Shows low blood pH (acidic), low oxygen, and high carbon dioxide levels.
• Pulse oximetry: Checks oxygen levels in the blood.
• Other tests if needed: Echocardiography to check the heart and blood flow, and blood or tracheal cultures to rule out infection.

How Is Meconium Aspiration Syndrome Treated?Treatment for MAS depends on the amount of meconium the baby has inhaled and how well they are breathing.

• No treatment needed: If the baby is active and crying at birth, usually no treatment is required.
• Suction: Doctors may clear meconium from the baby’s mouth, nose, or throat using a bulb syringe or a thin tube.
• Oxygen support: If the baby struggles to breathe, oxygen is given through a mask or small tubes.
• Breathing machine (ventilator): Babies who cannot breathe well on their own may need a ventilator to keep their lungs inflated.
• Surfactant therapy: This medicine helps the lungs open and exchange oxygen more easily.
• Antibiotics: They are given if there is a risk of infection.
• Chest tapping (physiotherapy): It helps loosen secretions in the lungs.
• Radiant warmer: Keeps your baby’s body temperature normal.
• Nitric oxide: A special gas that relaxes blood vessels in the lungs and improves oxygen levels, used in severe cases.
• ECMO (extracorporeal membrane oxygenation): A heart-lung bypass machine used only in very severe cases to give the lungs time to heal.

Most babies with meconium aspiration syndrome are cared for in a special care nursery or NICU (Neonatal Intensive Care Unit). With the right support, many babies recover within a few days to weeks, depending on how much meconium was inhaled.



What are the complications of meconium aspiration syndrome?Meconium aspiration syndrome rarely causes any long-term complications. However, newborn babies who have meconium aspiration syndrome may be at an increased risk for:

• Asthma
• Pneumonia
• Pulmonary hypertension of the newborn (PPHN)
• Hypoxia
• Pneumothorax (collapsed lung)

The thought of your child having meconium aspiration syndrome can be worrying. However, it is important to remember that not every baby passes meconium in the stomach. Additionally, most babies recover fully with timely treatment and care. If meconium is present during delivery, doctors act quickly to support your baby’s breathing and prevent complications. While rare, some babies may face short-term or long-term issues, which is why close monitoring is important. With the right medical support, the outlook for babies with MAS is generally very positive.



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FAQs on When a Baby Breathes in Meconium: What Parents Should Know

What is meconium staining?

Meconium staining happens when a baby passes meconium before birth, turning the amniotic fluid green or brown. Meconium-stained amniotic fluid is more common in pregnancies that go past the due date.

Can Meconium Aspiration Syndrome Be Prevented?

No, you cannot prevent the baby from aspirating meconium. However, you can lower the risk. If a pregnancy goes beyond the due date, doctors may suggest inducing labour to lower the risk of MAS. If the water breaks and the fluid looks dark green or brown, it’s important to inform the doctor immediately, as this indicates meconium in the amniotic fluid.