OVERVIEW

What is neonatal meconium aspiration syndrome?

Neonatal meconium aspiration syndrome refers to a series of diseases primarily caused by lung damage when meconium enters a baby's lungs in the womb or during birth, including meconium pneumonia, respiratory failure, and pulmonary hypertension.

Normally, meconium is expelled after birth and does not affect the baby's breathing. However, in cases of illness, fetal hypoxia before birth can cause premature meconium discharge into the amniotic fluid, contaminating it. When the baby starts breathing, the mixture of dirty meconium and amniotic fluid is inhaled into the lungs, leading to subsequent symptoms.

Comprehensive treatments such as respiratory support, heart function protection, and infection control are required. The mortality rate is around 5%, and mild to moderate cases generally respond well to treatment.

Is neonatal meconium aspiration syndrome common?

The incidence of meconium-stained amniotic fluid is 4%–22%, and among these cases, the likelihood of developing meconium aspiration syndrome is 3%–12%. Post-term infants (gestational age >42 weeks) have a higher risk of meconium aspiration, and their condition tends to be more severe.

SYMPTOMS

What are the symptoms of a baby with meconium aspiration syndrome?

• The amniotic fluid is contaminated with stool, and green or yellow meconium mixtures can be seen on the baby's skin and hair.
• Prominent symptoms include: difficulty breathing, gasping, weak and faint crying (like a kitten's meow), inability to cry loudly (more like whimpering), and a purplish or dark complexion with foamy saliva resembling crab bubbles. These symptoms gradually worsen over time.
• In severe cases, the baby may turn completely purple, stop crying, and become unresponsive. Without prompt treatment, this condition can be life-threatening.

What other diseases can meconium aspiration syndrome cause?

Meconium aspiration syndrome may be associated with: neonatal pneumothorax, persistent pulmonary hypertension, respiratory failure, neonatal brain injury, sepsis, acidosis, pneumonia, heart failure, and other conditions. The more complications present, the more severe the baby's condition becomes.

CAUSES

What are the common causes of neonatal meconium aspiration syndrome?

Before birth, abnormal conditions in the uterine environment are the primary causes, such as inflammatory stimulation of the placenta, fetal hypoxia, and other situations that lead to the premature passage of meconium into the amniotic fluid.

Meconium-stained amniotic fluid is a prerequisite for meconium aspiration. If the amniotic fluid is clear, meconium aspiration will not occur. After contamination of the amniotic fluid, whether meconium aspiration syndrome develops depends on how much meconium the baby inhales during breathing. The more meconium inhaled, the higher the chance of developing meconium aspiration syndrome, and the more severe the symptoms.

What types of damage can occur after meconium enters a baby's lungs?

After meconium enters the lungs, it can cause three types of damage:

• Physical damage: Thick meconium blocks the trachea and bronchi, leading to uneven lung ventilation and resulting in hypoxia.

• Chemical damage: Meconium contains chemical substances such as bile acids, which can harm the alveoli, causing them to collapse and severely impairing gas exchange in the lungs.

• Biological damage: Meconium contains biological components like shed cells, which can promote bacterial growth and lead to severe bacterial infections.

These three types of damage collectively affect lung function. If not treated promptly or in severe cases, the baby may develop life-threatening respiratory failure.

Which babies are more prone to neonatal meconium aspiration syndrome?

• Post-term newborns are more likely to develop meconium aspiration syndrome, especially those with a gestational age greater than 42 weeks.

• Babies who experience hypoxia or asphyxia are more prone to meconium aspiration syndrome. Hypoxia or asphyxia can cause the amniotic fluid to become contaminated with meconium, and inhaling this contaminated fluid into the lungs can lead to the syndrome.

When is neonatal meconium aspiration syndrome most likely to occur?

Neonatal meconium aspiration syndrome occurs at birth, with mild symptoms initially.

Around 48 hours after birth, the condition gradually progresses, reaching its peak severity after 48 hours.

DIAGNOSIS

What tests are needed to diagnose neonatal meconium aspiration syndrome?

Chest X-ray, blood tests including complete blood count, blood gas analysis, blood culture, cardiac ultrasound, head CT or head MRI are required.

Why are these tests necessary for diagnosing neonatal meconium aspiration syndrome? What are their purposes?

• Chest X-ray: This is the most direct examination to assess lung inflammation. Meconium aspiration syndrome shows characteristic changes on chest X-rays, which can help diagnose the condition, evaluate its severity, and monitor treatment effectiveness.

• Blood gas analysis: A blood test that helps assess the child's cardiopulmonary function. It is essential for detecting respiratory failure.

• Complete blood count: Helps determine whether there is a bacterial infection and assess its severity.

• Blood culture: Identifies the specific type of infectious bacteria.

• Cardiac ultrasound: Evaluates complications such as pulmonary hypertension and assesses heart function.

• Head CT or MRI: Assesses the child's brain condition and checks for any brain damage.

What should be noted when performing these tests for diagnosing neonatal meconium aspiration syndrome?

• Meconium aspiration syndrome requires hospitalization, and the attending physician will arrange the necessary tests. Parents should accompany the child for examinations as instructed by the doctor.

• Cardiac ultrasound and head MRI may require the child to be asleep. If the child cannot fall asleep naturally, sedation may be used under medical supervision. Short-acting sedatives, when properly selected, are safe and will not harm the child. Avoid refusing necessary tests due to concerns about sedation.

TREATMENT

Can meconium aspiration syndrome in newborns be cured?

Meconium aspiration syndrome can be cured.

• Mild to moderate cases respond well to treatment.
• Severe cases complicated by heart or brain conditions are more challenging to treat and may be life-threatening, with a mortality rate of around 5%.

Which department should be consulted for neonatal meconium aspiration syndrome?

Neonatology Department or Neonatal Intensive Care Unit (NICU).

How is neonatal meconium aspiration syndrome treated?

Comprehensive treatment in the neonatal ward is required, including:

• Respiratory support (e.g., oxygen therapy, mechanical ventilation) to ensure adequate oxygenation.
• Cardiac function protection and pulmonary hypertension treatment to prevent heart failure.
• Infection control. Severe cases may require pulmonary surfactant administration to aid lung recovery and alleviate respiratory failure.
• Extracorporeal membrane oxygenation (ECMO) may be considered for combined cardiopulmonary failure.

What should be noted during hospitalization for neonatal meconium aspiration syndrome?

In non-accompanying wards, mothers should maintain breast milk production by regular pumping and freezing milk in storage bags. This ensures the baby receives breast milk after discharge, promoting health and neurological development while strengthening the mother-child bond. In accompanying wards, mothers can continue breastfeeding while cooperating with medical treatment.

Is follow-up required after discharge for neonatal meconium aspiration syndrome?

Yes, follow-ups (typically monthly) are needed to assess brain damage recovery, including physical exams and chest X-rays.

Can neonatal meconium aspiration syndrome recur?

No, because meconium aspiration only occurs during birth.

Does neonatal meconium aspiration syndrome cause sequelae?

The syndrome itself leaves no long-term sequelae after recovery. However, concurrent brain damage due to fetal hypoxia may lead to complications.

DIET & LIFESTYLE

What should be noted in the diet for neonatal meconium aspiration syndrome?

Breastfeeding is preferred. Formula should only be used as a last resort if breastfeeding is unavailable.

What should be noted in daily life for neonatal meconium aspiration syndrome?

• After returning home, parents should have more skin-to-skin contact with the baby, such as gentle massages, as physical closeness promotes the child's development.
• Engage in eye contact and talk to the baby frequently, as these interactions benefit brain development.
• Avoid allowing visitors to see or kiss the baby, as close contact may expose the child to infections, especially since they are recovering from a serious illness.
• Minimize outings and social visits to reduce the risk of infection.

PREVENTION

Can Neonatal Meconium Aspiration Syndrome Be Prevented?

Yes.

Prevention of meconium aspiration primarily involves regular prenatal checkups.

If abnormalities such as reduced fetal movement or premature rupture of membranes are detected in late pregnancy, seek medical attention promptly. Doctors can identify fetal hypoxia early through methods like fetal heart rate monitoring and ultrasound. Taking timely measures, such as cesarean delivery or assisted delivery, can help the baby be born sooner. After birth, active resuscitation and clearing the infant's airway can reduce the chances of meconium aspiration.

If meconium aspiration does occur, parents should not panic. With active treatment, the prognosis is generally good. Cooperating fully with medical care can better support the baby's recovery.