Pulmonary aspiration is the entry of material (such as pharyngeal secretions, food or drink, or stomach contents) from the oropharynx or gastrointestinal tract into the larynx (voice box) and lower respiratory tract (the portions of the respiratory system from the trachea—i.e., windpipe—to the lungs). A person may either inhale the material, or it may be delivered into the tracheobronchial tree during positive pressure ventilation. When pulmonary aspiration occurs during eating and drinking, the aspirated material is often colloquially referred to as “going down the wrong pipe.”

One type of aspiration that may occur during birth is meconium aspiration, also referred to as meconium aspiration syndrome, or MAS.  Although it can be serious, most cases of MAS are not.

Meconium aspiration can occur before, during, or after labor and delivery when a newborn inhales (aspirates) a mixture of meconium and amniotic fluid. Meconium is the baby’s first feces, 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 danger is that the inhaled meconium can 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.

Meconium aspiration syndrome can affect the baby’s breathing in a number of ways, including chemical irritation to the lung tissue, airway obstruction by a meconium plug, infection, and the inactivation of surfactant by the meconium (surfactant is a natural substance that helps the lungs expand properly).

The severity of the condition depends on the amount of meconium the baby has inhaled and other conditions, like the presence of infections in the uterus of if the baby is past due.

Generally, the more meconium a baby inhales, the more serious the condition.

Image by BruceBlaus Creative Commons License

Image by BruceBlaus Creative Commons License

Pulmonary aspiration. (2016, July 30). In Wikipedia, The Free Encyclopedia. Retrieved 17:47, July 30, 2016, from https://en.wikipedia.org/w/index.php?title=Pulmonary_aspiration&oldid=732255969

Meconium aspiration syndrome. (2016, September 16). In Wikipedia, The Free Encyclopedia. Retrieved 17:44, September 16, 2016, fromhttps://en.wikipedia.org/w/index.php?title=Meconium_aspiration_syndrome&oldid=739742019