Meconium Aspiration Syndrome

Quick Answer

If a newborn passes his or her first feces in the womb, it can cause meconium aspiration syndrome. This is because any type of fetal distress in the womb can make a baby gasp and breathe in whatever is in the amniotic fluid, including meconium (feces). Though it is usually very treatable, meconium aspiration syndrome is a top cause of severe illness and death in newborns.

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What Is Meconium Aspiration Syndrome?

Meconium is the first feces of a newborn. It is usually passed in the first few hours to days after a baby is born, however, some pass it while they are still in the womb. Meconium aspiration syndrome occurs when meconium that was passed in the womb is breathed into the lungs of the baby.

If it is treated properly, meconium aspiration syndrome usually resolves without any problems. However, if the condition is not treated, or if treatment is delayed, it may cause the baby’s lungs to collapse because of overexpansion or blockage. It may also cause lung infection and persistent pulmonary hypertension.

Quick Facts About Meconium Aspiration Syndrome

  • Meconium aspiration syndrome usually affects full-term, but small, babies at 37-41 weeks of pregnancy.
  • The International Journal of Pediatrics estimates that about 0.18% of full-term newborns could experience meconium aspiration syndrome.
  • Meconium aspiration syndrome increases the chances of serious infections, such as pneumonia.
  • Most babies with meconium aspiration syndrome have a complete recovery, but if the condition is severe, it can be fatal.

Causes of Meconium Aspiration Syndrome

Causes of meconium aspiration syndrome can occur when a fetus experiences stress due to infection or decreased oxygen levels while still in the womb. This stress may cause the baby to take forceful gasps — and if the amniotic fluid has meconium in it, it can travel into their lungs as they inhale.

Meconium Aspiration Syndrome Risk Factors

Babies are more likely to pass meconium while still in the womb if:

  • Delivery is difficult or long
  • They are born past their due date
  • The mother has medical conditions, such as diabetes or high blood pressure
  • The mother used drugs or smoked during pregnancy

If an expectant mother is past her due date, doctors may recommend inducing labor to prevent meconium aspiration syndrome.

Symptoms of Meconium Aspiration Syndrome

If a pregnant woman’s water breaks and has a yellow or green tint, it could mean that there is meconium in the amniotic fluid. In these cases, health care professionals should be notified immediately to prevent complications.

Other symptoms that may be present in the baby include:

  • Bluish skin color
  • Breathing problems or a slow heart rate
  • Limpness at birth
  • Meconium stains on the baby

Diagnosing Meconium Aspiration Syndrome

Meconium aspiration syndrome is suspected if a newborn who was born through meconium-stained fluid also has breathing problems. In these cases, a chest X-ray may be administered to confirm the diagnosis.

Other tests may be performed to not only diagnose meconium aspiration syndrome but also to rule out other conditions, such as heart problems or pneumonia.

These tests include:

  • Using a fetal monitor before birth to check heart rate
  • Using a laryngoscope to look for meconium-stained vocal cords
  • Checking for abnormal breathing with a stethoscope
  • Performing a blood gas analysis to check blood acidity, increased carbon dioxide, and decreased oxygen
  • Taking a chest X-ray to look for streaky areas in the lungs

Blood cultures may also be done to look for certain kinds of bacteria that could be signs of meconium aspiration syndrome.

Meconium Aspiration Syndrome Long Term Effects

Most newborns recover from complications related to meconium aspiration syndrome. That said, breathing problems can occur in some cases, with rapid breathing persisting for days. In severe cases — about 30-50% — a breathing support such as a ventilator may be needed.

Meconium can cause difficulty breathing due to:

  • Clogging of the airways
  • Irritation to the airways
  • Injury to lung tissue

In rare cases, meconium aspiration syndrome can cause permanent damage to the lungs. If a lack of oxygen in the uterus is prolonged, brain damage can occur. Additionally, babies with meconium aspiration syndrome may be at greater risk of asthma later in life.

About 75% of babies with meconium aspiration syndrome develop one or more complications. In rare cases, these complications can turn fatal.

Meconium Aspiration Syndrome Treatment Options

Usually, babies with meconium aspiration syndrome require special care in the neonatal intensive care unit (NICU). Oxygen is given for breathing difficulties if needed. This may include a breathing tube or CPAP machine.

If meconium aspiration syndrome is detected, the newborn’s mouth should be suctioned as soon as possible in delivery. If there is thick meconium staining accompanied by fetal distress, further treatment is needed.

Treatments to help improve breathing may include:

  • Antibiotics for infection
  • Extracorporeal membrane oxygenation to pump blood through an artificial lung
  • Inhaled nitric oxide to open blood vessels
  • Surfactant to help open the lungs
  • Tapping on the chest to loosen secretions
  • Use of a warmer to keep the body temperature normal

Depending on how much meconium was inhaled, most babies with meconium aspiration syndrome get better within a few days to a few weeks.

Compensation for Meconium Aspiration Syndrome Related to Medical Negligence

Failing to properly diagnose or respond to meconium aspiration syndrome can result in oxygen deprivation that causes brain damage or even death. If your baby was hurt because of meconium aspiration syndrome, it could be considered medical negligence — and legal compensation may be available to you.

Contact the Birth Injury Justice Center to consult with our experienced team of Patient Advocates and get a free legal case review.

Birth Injury Support Team

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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  2. Johns Hopkins Medicine. (n.d.) Meconium Aspiration Syndrome. Retrieved February 26, 2021 from,is%20past%20its%20due%20date
  3. Kandola, A. (2020). Causes and symptoms of meconium aspiration syndrome. Retrieved February 26, 2021 from
  4. Merck Manual Consumer Version. (n.d.) Meconium Aspiration Syndrome. Retrieved February 26, 2021 from,a%20sterile%20substance%20called%20meconium