What is meconium aspiration

Meconium aspiration occurs when a baby breathes in amniotic fluid containing meconium (the baby’s first stools). Meconium is passed into the amniotic fluid in about 10 percent of births. It usually occurs in babies born at term (37 to 41 weeks) or post-term (after 42 weeks).

Meconium particles in the amniotic fluid can block small airways and prevent the exchange of oxygen and carbon dioxide after birth. Some babies have immediate respiratory distress and have to be resuscitated at birth. Others develop respiratory distress within a few hours.

Some babies with meconium aspiration need a mechanical ventilator (breathing machine) because of the difficulty breathing. The plugged airways may cause air to be trapped and leak into the tissues in and around the lungs. Infection can also occur causing pneumonia. Although the condition often improves within a few days, severe meconium aspiration, and the respiratory problems it causes, may lead to death in a small number of babies.

What causes meconium aspiration?

Before or during labor, the fetus sometimes passes the meconium stool into the amniotic fluid. It is not clearly understood why this happens. It may be a natural event, but it is also thought to be related to fetal distress in some babies. When the thick meconium mixes into the amniotic fluid, it is swallowed and breathed into the airway of the fetus. As the baby takes the first breaths at delivery, meconium particles enter the airway and can be aspirated (inhaled) deep into the lungs.

Meconium aspiration prevention

To prevent problems that lead to meconium being present, stay healthy during pregnancy and follow your health care provider’s advice.

Your doctor will want to be prepared for meconium being present at birth if:

• Your water broke at home and the fluid was clear or stained with a greenish or brown substance.
• Any testing done during your pregnancy indicates there may be problems present.
• Fetal monitoring shows any signs of fetal distress.

Early identification of meconium aspiration is essential to preventing severe aspiration problems. A technique called amnioinfusion is sometimes used during labor with meconium-stained amniotic fluid. This procedure uses a small tube inserted into the uterus through the vagina. Sterile fluid is then infused through the tube to help dilute the thick meconium.

Meconium aspiration symptoms

Meconium in the amniotic fluid gives the fluid a greenish color. This is called meconium staining. Babies who have been exposed to meconium in the amniotic fluid for a long time may have yellowed skin and nails.

The following are the most common symptoms of meconium aspiration. However, each baby may experience symptoms differently. Symptoms may include:

• Rapid breathing
• Retractions (pulling in of the chest wall)
• Grunting sounds with breathing
• Cyanosis (blue coloring)
• Overdistended chest because of trapped air

The symptoms of meconium aspiration may resemble other conditions or medical problems. Always consult your baby’s doctor for a diagnosis.

Meconium aspiration diagnosis

The presence of meconium in the amniotic fluid is key to the diagnosis. A chest X-ray also helps diagnose meconium aspiration. X-rays are a diagnostic test that uses invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs onto film.

Meconium aspiration treatment

Early detection is key. A fetal monitor can detect if your baby is experiencing stress. If your doctor thinks your baby may have inhaled meconium, a special care team should be present during delivery. If after the baby is born, he’s active and crying, no treatment is necessary.

However, if the baby has trouble breathing, the doctor will quickly need to clear away as much meconium as possible to decrease the amount of meconium the baby inhales. He’ll suction the mouth, nose, and throat. Then he’ll insert a tube called a laryngoscope down the baby’s throat and into the trachea to remove any meconium there.

Specific treatment for meconium aspiration will be determined by your child’s doctor based on the following:

• The amount and thickness of the meconium
• The length of time the baby was exposed
• The degree of respiratory distress

At delivery, treatment may include:

• Suctioning of the upper airways (nose, mouth, and throat)
• Suctioning of the lower airways through an endotracheal tube (ET) placed in the windpipe, although this is not recommended routinely unless it is necessary
• Supplemental oxygen given by face mask or mechanical ventilator

If your baby is not breathing or has a low heart rate, a facemask with oxygen can help inflate the baby’s lungs and help him or her breathe. Your baby may need to be monitored closely in a newborn intensive care unit (NICU). In the NICU, he or she may get:

• Oxygen therapy.
• Antibiotics to treat infection.
• Surfactant (a substance that helps the lungs expand properly).
• A radiant warmer to control his temperature.
• Frequent blood tests to see if he’s getting enough oxygen.

Meconium aspiration long term effects

In most cases of meconium-stained fluid, the outlook is excellent and there are no long-term health effects. While rapid breathing may continue for several days, it’s rare for a baby with meconium aspiration syndrome to experiences any long-term damage. However, babies who experienced meconium aspiration syndrome may be at higher risk for an asthma-like disease called “reactive airway disease.” This can cause wheezing, coughing, and shortness of breath.

• Only about one half of babies with meconium-stained fluid will have breathing problems and only about 5% will have meconium aspiration syndrome.
• Babies may need extra support with breathing and nutrition in some cases. This need will often go away in 2 to 4 days. However, rapid breathing may continue for several days.
• Meconium aspiration syndrome rarely leads to permanent lung damage.

Meconium may be present at birth in the amniotic fluid because there is a serious problem with the blood flow to and from the lungs. This is called persistent pulmonary hypertension of the newborn.

Meconium aspiration syndrome

Meconium aspiration syndrome refers to breathing problems that a newborn baby may have when:

• There are no other causes, and
• The baby has passed meconium (stool) into the amniotic fluid during labor or delivery

Meconium aspiration syndrome may occur if the baby breathes in (aspirates) this fluid into the lungs. Meconium aspiration syndrome can happen before, during, or after labor and delivery.

Meconium aspiration syndrome causes

Meconium is the early feces (stool) passed by a newborn soon after birth, before the baby starts to feed and digest milk or formula.

In some cases, the baby passes meconium while still inside the uterus. This can happen when babies are “under stress” due to a decrease in blood and oxygen supply. This is often due to problems with the placenta or the umbilical cord.

Once the baby passes the meconium into the surrounding amniotic fluid, they may breathe it into the lungs. This may happen:

• While the baby is still in the uterus
• During delivery
• Immediately after birth

The meconium can also block the infant’s airways right after birth. It can cause breathing problems due to swelling (inflammation) in the baby’s lungs after birth.

Risk factors that may cause stress on the baby before birth include:

• “Aging” of the placenta if the pregnancy goes far past the due date (past 40 weeks)
• Decreased oxygen to the infant while in the uterus
• Diabetes in the pregnant mother
• Difficult delivery or long labor
• High blood pressure in the pregnant mother
• Poor intrauterine growth.

Meconium aspiration syndrome symptoms

Most babies who have passed meconium into the amniotic fluid do not breathe it into their lungs during labor and delivery. They are unlikely to have any symptoms or problems.

Babies who do breathe in meconium fluid may have the following:

• Bluish skin color (cyanosis) in the infant
• Working hard to breathe (noisy breathing, grunting, using extra muscles to breathe, breathing rapidly)
• No breathing (lack of respiratory effort, or apnea)
• Limpness at birth

Newborn babies with meconium aspiration syndrome have trouble breathing. They may breathe too quickly, grunt when they breathe, or use extra muscles to catch their breath. Their skin may have a bluish tint due to lack of oxygen, or a greenish tint from meconium staining. Their blood pressure may also be too low.

Meconium aspiration syndrome diagnosis

Before birth, the fetal monitor may show a slow heart rate that is slower than expected. During delivery or at birth, meconium can be seen in the amniotic fluid and on the infant.

The infant may need help with breathing or heartbeat right after birth. They may have a low Apgar score.

The health care team will listen to the infant’s chest with a stethoscope. This may reveal abnormal breath sounds, especially coarse, crackly sounds.

A blood gas analysis will show:

• Low (acidic) blood pH
• Decreased oxygen
• Increased carbon dioxide

A chest x-ray may show patchy or streaky areas in the infant’s lungs.

Meconium aspiration syndrome treatment

A special care team should be present when the baby is born if traces of meconium are found in the amniotic fluid. This happens in more than 10% of normal pregnancies. If the baby is active and crying, no treatment is needed.

If the baby is not active and crying right after delivery, the team will:

• Warm and maintain normal temperature
• Dry and stimulate the baby

This intervention is often all babies need to begin breathing on their own.

If the baby is not breathing or has a low heart rate:

• The team will help the baby breathe using a face mask attached to a bag that delivers an oxygen mixture to inflate the baby’s lungs.
• The infant may be placed in the special care nursery or newborn intensive care unit in order to be watched closely.

Other treatments may include:

• Antibiotics to treat possible infection.
• Breathing machine (ventilator) if baby is unable to breathe on their own or needs a large amount of extra oxygen.
• Oxygen to keep blood levels normal.
• Intravenous (IV) nutrition — nutrition through the veins if breathing problems are keeping baby from being able to feed by mouth.
• Radiant warmer to maintain body temperature.
• Surfactant to help lungs exchange oxygen. This is only used in more severe cases.
• Nitric oxide (also referred to as NO, an inhaled gas) to help blood flow and oxygen exchange in the lungs. This is only used in severe cases.
• ECMO (extracorporeal membrane oxygenation) is a kind of heart/lung bypass. It may be used in very severe cases.