An inhaled meconium can partially or completely block the baby’s airways

Emobileclinic Trending Topic: Meconium Aspiration

The desire of every couple and especially the expectant woman is to have an uncomplicated birth and a healthy baby. However, some babies do face delivery room complications. One of such complications is meconium aspiration, also known as Meconium Aspiration Syndrome (MAS). Although it can be serious, most cases of MAS are not. It can happen before, during, or after labor and delivery when a newborn inhales a mixture of meconium and amniotic fluid (the fluid in which the baby floats inside the amniotic sac). It is the baby’s first feces, or poop, which is sticky, thick, and dark green and is typically passed in the womb during early pregnancy and again in the first few days after birth.


The inhaled meconium can partially or completely block the baby’s airways. Although air can flow past the meconium as the baby breathes in, the meconium becomes trapped in the airways when the baby breathes out. The meconium irritates the baby’s airways and makes it difficult to breathe.

What it does to the baby?

Chemical irritation to the lung tissue

 Airway obstruction by a meconium plug


Inactivation of surfactant by the meconium 

The severity of MAS depends on the amount of meconium the baby inhales as well as underlying conditions, such as infections within the uterus or postmaturity (when a baby is overdue, or more than 40 weeks gestational age). Generally, the more meconium a baby inhales, the more serious the condition.

Although 6% to 25% of newborns have meconium-stained amniotic fluid, only about 11% of them will have some degree of MAS.


In the course of pregnancy, fluid usually moves in and out of the trachea (the upper part of the airway) only. Meconium can be inhaled into the lungs if the baby gasps while still in the womb or during the initial gasping breaths after delivery. The causes include?

Infection in the womb 

Hypoxia (decreased oxygen) which can make the baby’s intestinal activity increase and cause relaxation of the anal sphincter

Long or difficult delivery

Advanced gestational age

Mother who smokes cigarettes heavily or who has diabetes , high blood pressure (hypertension), or chronic respiratory or cardiovascular disease

Umbilical cord complications

Poor intrauterine growth (poor growth of the baby while in the uterus)

Signs and Symptoms

The medical doctor or the midwife will likely notice one or more symptoms of MAS in the course of delivery or after birth, including:

Dark green streaks or stains in the amniotic fluid

Discoloration of the baby’s skin — either blue (cyanosis) or green (from being stained by the meconium)

Breathing disorder including rapid breathing (tachypnea), labored (difficulty) breathing, or suspension of breathing (apnea)

Low heart rate in the baby before birth

Low Apgar score (given to newborns just after birth to quickly evaluate color, heartbeat, reflexes, muscle tone, and breathing)

Limpness in the baby

Postmaturity (signs that a baby is overdue, such as long nails)


If the baby has trouble breathing, the doctor will insert a laryngoscope into the trachea to remove any meconium. The doctor also will listen to the baby’s lungs to check for sounds that are common with MAS.

The doctor might order tests, such as a blood test (called a blood gas analysis) that helps determine if the baby is getting enough oxygen and a chest X-ray that can show patches or streaks on the lungs that are found in babies with MAS.


Suctioning of both the upper and lower airways.

Oxygen therapy

Antibiotics to treat infection

Use of surfactant

Nitric oxide inhalation

Frequent blood tests to see if the baby is getting enough oxygen

Babies with severe cases of MAS may come home from the hospital on oxygen. They may be more likely to have wheezing and lung infections during their first year, but lungs can regenerate new air sacs, so the long-term outlook for their lungs is excellent.

Possible Long-Term Complications

Severely affected babies are at risk for chronic lung disease and also may have developmental abnormalities and hearing loss. Babies diagnosed with MAS will be screened at the hospital for hearing problems or neurological damage.

Although very rare, severe cases of MAS can be fatal. But deaths from MAS have decreased greatly thanks to treatments such as suctioning and a reduction in the number of post-term births.


Pregnant woman needs to inform her doctor immediately if she sees meconium in the amniotic fluid when her water breaks, or if the fluid has dark green stains or streaks. Doctors also use a fetal monitor during labor to watch the baby’s heart rate for any signs of fetal distress.

In some cases, doctors may recommend amnioinfusion (diluting the amniotic fluid with saline) to wash meconium out of the amniotic sac before the baby has a chance to inhale it at birth.

For most infants who have inhaled meconium, early treatment can prevent further complications and help reassure anxious new parents.


See also  ''Treatment focuses on preventing the effects of the incompatibility''

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