Meconium Aspiration
What is it?
Meconium is the dark green material that is found in the intestines of the unborn fetus. It is normally released as a thick, dark green bowel movement at or right near the time of birth. However, an infant who is stressed may pass some meconium into the amniotic fluid before birth and breathe it into the lungs (called aspiration).
Who gets it?
Five to ten percent of all births have meconium staining of the amniotic fluid. Infants who are post term, experience a difficult delivery, or experience fetal distress and lack of oxygen during delivery are at a higher risk for meconium aspiration.
What causes it?
Infants who experience a stressful labor may experience a lack of oxygen. This, in turn, can cause the intestines to move and the muscles surrounding the anus to relax, releasing the meconium into the amniotic fluid. The fetus may gasp and breathe the thick meconium into the lungs during labor, or the meconium enters when the baby takes its first breath at birth.
What are the symptoms?
Infants who have inhaled meconium may appear limp at birth, have a bluish skin color, breath rapidly or with difficulty, or not breathe at all. When meconium is inhaled, it can block the infants airways either partially or completely. This can cause the air sacs, called alveoli, that are supplied by the airways to collapse, making breathing difficult. Meconium can also irritate the lungs and lead to inflammation and pneumonia. In severe cases, air is trapped in areas that are supplied by the blocked airways and the lungs become
overinflated. Overinflated lungs can, in turn, cause lung rupture and collapse, called
pneumothorax. However, infants with meconium aspiration rarely have permanent lung damage.
How is it diagnosed?
When a mother’s water breaks before delivery, the doctors and/or nurse always check the amniotic fluid for signs of the green meconium stain. When amniotic fluid contains
meconium, the fetus is monitored for signs of distress during delivery. Upon birth, the doctor can see meconium staining on the infant’s vocal cords using an instrument called a laryngoscope, and may hear crackling sounds in the lungs by listening to the infant's chest with a stethoscope. Other diagnostic tests include tests of blood oxygen levels and chest x-ray.
What is the treatment?
The newborn’s mouth, nose, and throat are suctioned immediately to remove any meconium fluid. If there were signs of fetal distress, meconium that has entered the baby’s windpipe (trachea) is removed through a tracheal tube, which suctions the lungs until there is no meconium in the suctioned fluid. If the infant is showing signs of respiratory distress, he or she is treated with oxygen. In cases of severe aspiration, infants may need the help of a ventilator, which is a mechanical device that forces air in and out of the lungs through a tube passed through the nose or mouth and into the trachea. Any infant with meconium aspiration is observed carefully for signs of complications.
Self-care tips
There is no way to prevent meconium staining. However, a thorough visual check of the amniotic fluid after the membranes have ruptured (water breaks) can reveal meconium staining and your doctor can take steps to remove the any inhaled meconium from the baby’s mouth and, if necessary, lungs.
This information has been designed as a comprehensive and quick reference
guide written by our health care reviewers. The health information written
by our authors is intended to be a supplement to the care provided by your
physician. It is not intended nor implied to be a substitute for
professional medical advice.
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