Meconium Aspiration Syndrome (MAS) – Symptoms, and Treatment.


The Meconium aspiration syndrome is a respiratory disorder occurring in the newborn babies. MAS develops when the meconium is inhaled by the babies when they are in the womb or during the labor. Due to which meconium is trapped in the airways and lungs that causes suffocation during respiration.


Meconium is a sterile fecal material dark green in color that is produced in the intestine of the fetus before the labor. It consists of intestinal epithelial cells, mucus, lanugo, and intestinal secretions such as bile.

Usually, the meconium is expelled out after 1-2 days when the mother starts feeding the baby. In some cases, it comes out from the intestine into the amniotic fluid before the delivery of a baby due to intrauterine stress. In such situation, the meconium-stained amniotic fluid (MSAF) is aspirated by the fetus into the airways of the lungs. This is known as Meconium aspiration syndrome (MAS). MAS makes the baby suffer from difficulty breathing. It affects the surfactants in alveoli and causes collapsed airways finally leads to respiratory distress.


The term Meconium first described by the historical Greeks to the contemporary, meconium and its effect on the newborn infant has remained an enigma.

The term turned into coined by using Aristotle from the Greek phrase “meconium arion” meaning “opium-like” as he believed that the substance-induced fetal sleep


MSAF is located in 7% to 22% of time period deliveries, with better quotes (22% to 44%) in publish-time period deliveries (>42 weeks). A higher occurrence of MSAF is mentioned in black and South Asian pregnancies. It is uncommon (<5%) in deliveries at <34 weeks gestation. The low occurrence of MAS can be defined on the idea of the low frequency of MSAF in preterm toddlers as gut peristalsis isn’t always well evolved. One percent of babies are born through minimum meconium and seven% through maximum meconium.

Although a lower inside the prevalence of MAS within the US was mentioned in the 1990s, later reports display that MAS is still a challenge. Populace research from Australia and France also show that the frequency of MAS and MSAF has step by step decreased over the past many


  • Aging of the placenta if the labor happens far the due date
  • Prolonged labor
  • Umbilical cord compression due to changing position of baby
  • Shortage in oxygen supply to the fetus in the womb due to cord compression
  • Decreased oxygen supply in babies increase the intestinal activity and cause relaxation of the anal sphincter
  • Overdue date or postmaturity
  • Underdeveloped circulatory system or abnormal blood pressure in the fetus
  • Difficult labor
  • Uterine stress
  • Chronic respiratory condition in the pregnant woman

Risk factors of meconium aspiration syndrome

  • Placental insufficiency
  • Maternal hypertension
  • Drug abuse, especially tobacco and cocaine during pregnancy
  • Preeclampsia
  • Oligohydramnios
  • Uterine infections
  • Acidosis
  • Maternal diabetes


Before or at the time of birth doctor will notice the common symptoms and signs of MAS includes:

  • Dark green streaks or stains or meconium appears in the amniotic fluid
  • Baby’s skin colour changes into blue (cyanosis) or green due to the staining of meconium
  • Breathing problems such as fast breathing (tachypnea), labored (difficulty) breathing, or breath apnea
  • Before birth, baby’s heart rate will be low
  • Limpness in the baby
  • Staining of Amniotic fluid as greenish yellow
  • Baby shows low Apgar score. This indicates the severe stress during the birth process

Complications of meconium aspiration syndrome

The possible complications associated with Meconium Aspiration Syndrome include:

  • Chronic lung disease in babies who are severely affected with MAS
  • Some babies who are affected severely with MAS may lose their sense of hearing or they may have developmental abnormalities such as bronchopulmonary dysplasia, cerebral palsy, seizures and hypoxic brain damage.
  • Brain damage may occur if oxygen supply is cut off for too long time
  • Neurological damage
  • Baby’s breath may affect because of irritation to the lung tissue. It is due to the blockage of meconium in the airway or by infection. This leads to the inactivation of lung surfactant ( the natural substance that filled in the lungs to keep the air sacs open)
  • Collapsed lungs

Diagnosis and test

Diagnosis for MAS is conducted through the following tests such as follows:

  • Blood gas analysis test to know the enough supply of oxygen to baby
  • The chest X-ray to see the streaky or patches which show meconium entered in the baby’s lungs
  • Doctor may use a stethoscope on baby’s chest to listen the abnormal breath sounds mainly coarse and crackly sounds
  • The Laryngoscope is inserted into the throat to observe the vocal cords and to see the meconium stain in the vocal cords

Treatment and medications

After birth, if the baby is active and crying, no treatment is needed. There skilled physician should be available to review infants during delivery to check whether the meconium is found in amniotic fluid.

If the baby is not active and not crying, the suction tube is inserted into the trachea and it is suctioned until the meconium content is not seen in suction tube.

If the baby is not breathing properly or heart rate is low, the skilled team will help the baby to breath by placing a face mask that is attached to a bag and an oxygen mixture which will inflate the baby’s lung.

The baby is kept in special care in neonatal intensive care (NICU) for a few days to monitor and to treat. Other treatments may include

  • Antibiotics (ampicillin and gentamycin) are given to get away from infections
  • IV to support nutritional requirements
  • Breathing support using ventilator is to keep the baby’s lungs inflated
  • Radiant warmers to keep control body temperature
  • In case the above machines fails the Extra Corporeal Membrane Oxygen (ECMO) is used as an artificial heart and lung machine to support delivery of oxygen to new born

Intubated infant receiving ventilator assistance

Prevention of meconium aspiration syndrome

Preventive methods are as follows

  • Intrapartum suctioning ( After head delivered, immediately suctioning has to be carried out)
  • Antenatal monitoring of the fetus and placenta in post-maturity births
  • Tracheal intubation and suctioning in severe respiratory distress



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  1. Chukwugozie Alieze

    in other to avoid meconium aspiration syndrome, is it better to induce labour in the mother before 37 weeks of gestation.

  2. what is the pathophysiology behind that as you continue breast feeding the baby the meconium is cleared?

    • We will soon update about pathophysiology. During the first day of birth all meconium will get excreted and when baby continue to breastfeed the meconium will get clear.

  3. Already suffered birth asphyxia….is piracetam Rx useful?

  4. how long it can effect the baby or how long it can last?

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