Meconium Aspiration Syndrome Symptoms

Fact-Checked and Medically Reviewed by:
Katie Lavender, RN Registered Nurse
Quick Answer

Meconium aspiration syndrome (MAS) happens when a baby inhales a mixture of amniotic fluid and meconium, their first feces. When treated promptly, MAS is often harmless. However, if it goes unnoticed, MAS can cause respiratory distress, severe illness, and even death. Learn about common meconium aspiration syndrome signs and symptoms.

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What is Meconium Aspiration Syndrome?

A doctor uses a stethoscope on a newborn to listen for breathing troubles that could be meconium aspiration syndrome symptoms.

Meconium aspiration syndrome (MAS) happens when a baby breathes in their first feces (meconium) while still in the womb or at delivery when taking their first breaths. This can be due to the baby experiencing stress.

Meconium aspiration syndrome, when treated promptly, often resolves without complications. However, delayed treatment can lead to severe lung issues.

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What Are Common Meconium Aspiration Symptoms?

There are several common meconium aspiration syndrome symptoms that delivery teams are trained to watch for. These include rapid breathing, chest retractions (pulling in of the chest), grunting sounds when breathing, bluish skin tone, and limpness shortly after birth.

Did you know

The Apgar test is a tool used to check the health of a newborn at delivery based on various signs. It can help identify symptoms of meconium aspiration syndrome. Learn more about the Apgar test.

Here is more information on meconium aspiration syndrome signs and symptoms.

1. Breathing Troubles

lungs, block the airway and block surfactant (the substance that helps open the newborn’s lungs at birth). This can cause difficult, rapid, and labored breathing. Babies may also make grunting sounds.

A baby with MAS may require the assistance of a mechanical breathing machine.

2. Skin Color Changes

Babies with MAS may experience skin color changes due to breathing difficulties. Light-skinned babies may develop blue lips or skin (cyanosis), and babies with darker skin may develop white or gray skin. This skin color means that the baby is not getting enough oxygen.

Breathing troubles can be serious, and health care providers should intervene right away if a baby is showing skin color changes. It is one of the more concerning meconium aspiration syndrome symptoms.

3. Dark Stains or Streaks in the Amniotic Fluid

Amniotic fluid is normally clear or slightly yellow. If the fluid is brown or dark green, the baby has probably passed meconium while in the womb. This may be a sign of fetal distress.

4. Limpness in the Baby After Birth

Limpness in a baby after birth indicates reduced muscle tone and can be a symptom of MAS.

Meconium Aspiration Syndrome Risk Factors

MAS risk factors should alert health care providers to watch for meconium aspiration syndrome symptoms.

Risk factors of meconium aspiration syndrome include:
  • Decreased oxygen to the baby during pregnancy
  • Difficult or prolonged labor
  • Maternal diabetes or high blood pressure
  • Post-term pregnancy (when a baby is past their due date)
  • Presence of meconium in the amniotic fluid
  • Problems with the umbilical cord or placenta
  • Smaller-than-average babies

How Do You Detect Meconium Aspiration Syndrome Symptoms?

When a baby shows meconium aspiration symptoms, delivery teams are trained to respond. If it is treated properly, MAS usually resolves without any problems.

Here are some ways doctors detect meconium aspiration syndrome symptoms:
  • Listen with a stethoscope to identify abnormal breath sounds, especially crackly, coarse sounds.
  • Order a chest X-ray of your baby’s lungs. X-rays of infants with MAS feature streaky or patchy areas on the lungs.
  • Perform a blood gas analysis. A blood gas analysis of a baby with MAS shows decreased oxygen, low blood acidity, and increased carbon dioxide.
  • Use a laryngoscope to check your baby’s vocal cords (larynx) for meconium stains with a specialized camera tube. The tool may be able to remove meconium particles and other tissues from your child’s larynx.

Recognizing meconium aspiration symptoms is crucial. When detected promptly, treatment is highly effective to avoid long-term damage.

Treatment for Meconium Aspiration Syndrome Symptoms

When babies show meconium aspiration syndrome signs and symptoms, doctors have several treatment options to help them recover. MAS treatments address the symptoms and ensure the baby can breathe and function properly.

Treatments depend on whether your child has mild or severe MAS, and may include:
  • Inhaled nitric oxide to open blood vessels and restore oxygen to the brain and other affected tissues.
  • Mechanical ventilation, such as extracorporeal membrane oxygenation (ECMO), pumps oxygenated blood throughout your baby’s body to relieve respiratory distress.
  • Suctioning meconium-stained amniotic fluid from the baby’s upper airways, including the throat, mouth, and nose. Doctors only recommend this for vigorous full-term newborns who had no signs of fetal distress during pregnancy.
  • Using saline to dilute meconium in the amniotic fluid. This is called amnioinfusion and is done before the infant is delivered but after the mother’s water breaks.

Can Medical Malpractice Lead to Meconium Aspiration Syndrome?

Yes, medical malpractice can lead to MAS. If health care professionals fail to promptly detect and manage meconium aspiration syndrome symptoms, birth injury medical malpractice could be involved.

Situations that could be considered medical malpractice include:

  • Delayed response to fetal distress
  • Failure to provide enough oxygen to the baby after delivery
  • Inadequate monitoring
  • Not performing a timely cesarean section (C-section)

Midwives, doctors, nurses, and other health care professionals are responsible for consistently monitoring your baby’s health throughout your pregnancy.

If they don’t do this, they may miss meconium aspiration syndrome symptoms, such as dark stains in the amniotic fluid and signs of fetal distress.

If you believe medical malpractice caused your child’s MAS, you may have legal options.

Find out with a free case review right now.

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Legal Help for Meconium Aspiration Syndrome

If your delivery team failed to detect and treat your baby’s meconium aspiration syndrome symptoms, you may be able to take legal action with the help of a birth injury lawyer.

The Birth Injury Justice Center is committed to helping families get justice and compensation for the harm that was done to their child.

We partner with some of the best birth injury law firms in the country. See if we can connect you with a top birth injury lawyer near you.

Call (800) 914-1562 day or night to talk directly with one of our Patient Advocates. You can also fill out our case review form to find out how we may be able to help.

Meconium Aspiration Syndrome Symptoms FAQs

What are the causes of meconium aspiration syndrome?

MAS can happen for various reasons, including stress resulting from low oxygen levels or an infection. Stress makes the baby take deep gasps, causing them to inhale amniotic fluid. The baby may develop MAS if the amniotic fluid contains meconium.

What are the signs and symptoms of meconium aspiration syndrome?

Some common meconium aspiration syndrome symptoms are:

  • Bluish skin tone
  • Grunting when breathing
  • Rapid heartbeat
  • Struggling to cry

Babies with MAS may need special care in the hospital. Thankfully, with proper care, most babies with meconium aspiration syndrome recover well.

Do babies recover from meconium aspiration syndrome?

Yes, most babies recover from meconium aspiration syndrome (MAS) within several days. If you suspect your baby has MAS, talk to your doctor as soon as possible.

Is meconium aspiration syndrome dangerous?

In most babies, MAS is usually treated and managed within several days. However, babies with MAS are at a slightly higher risk for asthma, pneumonia, collapsed lung (pneumothorax), and persistent pulmonary hypertension of the newborn (PPHN).

Severe cases of MAS may cause hypoxia (lack of oxygen in tissues) and brain damage.

What are the long-term effects of swallowing meconium?

Long-term effects of swallowing meconium include asthma-like symptoms, pneumonia, poor growth, and lack of oxygen. In some cases, lack of oxygen can lead to brain damage and conditions such as cerebral palsy.

How do you recognize meconium aspiration symptoms and diagnose the syndrome?

Doctors identify meconium aspiration symptoms and diagnose the syndrome by performing the following tests:

  • Blood gas analysis
  • Chest X-ray
  • Laryngoscope to check the larynx (voice box) for meconium stains

How do I know if my baby passed meconium in the womb?

If your baby passed meconium in the womb, doctors may see the following signs:

  • Dark streaks or stains in the amniotic fluid
  • Difficulty breathing
  • Limp body
  • Skin color has changed to a bluish tone
Birth Injury Support Team
Reviewed by:Katie Lavender, RN

Registered Nurse

  • Fact-Checked
  • Editor

Katie Lavender has over 8 years of experience as a Registered Nurse in postpartum mother/baby care. With hands-on experience in Labor and Delivery and a role as a Community Educator for newborn care, Katie is a staunch advocate for patient rights and education. As a Medical Reviewer, she is committed to ensuring accurate and trustworthy patient information.

The Birth Injury Justice Center was founded in 2003 by a team of legal professionals to educate and empower victims and families affected by birth injuries. Our team is devoted to providing you with the best resources and legal information for all types of birth injuries.

View Sources
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  5. National Library of Medicine: MedlinePlus. (n.d.) Meconium aspiration syndrome. Retrieved June 30, 2024, from
  6. Nemours KidsHealth. Meconium aspiration syndrome (MAS). (2020, January.) Retrieved June 30, 2024, from