Meconium Aspiration – Related Conditions

Meconium aspiration itself can cause complications and respiratory difficulties that are usually resolved within a few days after delivery. However, there are some conditions that are related to or arise out of the syndrome, depending on the amount and thickness of meconium that was aspirated, including but not limited to the following.

Infection

When infants are diagnosed and treated, they may be at a higher risk of infection. This is both because their immune systems may be compromised due to the presence of meconium in their systems (meconium can be a fertile environment for non-native organisms to grow), the weakness introduced by respiratory difficulties triggered by the meconium, but also because they may be subject to various invasive procedures as treatment.

Pneumothorax and Pneumomediastinum

Pneumothorax is the term for when air enters the chest cavity other than the lungs. Infants that have aspirated meconium may have, as one of their respiratory difficulty components, difficulty exhaling air that they have inhaled. This may lead to an overstretching of their alveoli and lungs, and if the alveoli rupture, this may cause air leakage from the lungs into the thorax (the area between the chest wall and the lung).

Relatedly, the same overstretching of an infant’s alveoli when they have trouble exhaling (as a result of meconium aspiration and blockage) can lead to air leakage into the mediastinum. The mediastinum is, generally, the central chest cavity that includes the heart, thorax, thymus, trachea, lymph nodes, and various other tissues.

Pneumothorax and pneumomediastinum can further compromise an infant’s respiratory functioning and, potentially, also an infant’s cardiovascular functioning. Importantly, if pneumothorax is not addressed and treated immediately, it can exacerbate the hypoxia (lack of oxygen) that an infant already suffers due to respiratory distress and lead to persistent pulmonary hypertension of the newborn (PPHN).

Persistent Pulmonary Hypertension of the Newborn (PPHN)

PPHN is the term used to describe a condition found in newborns that fail to transition from their fetal circulatory system to normal circulation. The biggest difference between the two systems is that a fetus did not use its lungs to help circulate oxygen and other important nutrients through the body and to other vital organs. However, when a baby takes its first breath, this inhalation of oxygen normally triggers normal circulation by which the blood and oxygen exchange happens through the lungs, which allows oxygen to be delivered by the blood to the rest of the body. Pneumothorax (as described above) and hypoxia (the lack of oxygen in the blood and organs), both of which are some typical effects of more severe meconium exposure, can both trigger PPHN.

Chronic Lung Disease

Chronic lung disease is one of the potential long-term effects of meconium aspiration, and it can occur due to the use of ventilators (intubation) and oxygen treatment that can be necessary to address the respiratory difficulties caused by it.

Cerebral Palsy, Seizure, and Other Neurological Disorders

Depending on the level of fetal distress, if the fetus aspirated meconium in the womb, and the severity of oxygen deprivation after birth, the fetus or infant may have had difficulties delivering oxygen to the brain. This, in turn, may have caused neurological damage, including cerebral palsy and seizures, which would usually require additional, ongoing care.

Ongoing Respiratory Difficulties

Infants that aspirated meconium may also be at a higher risk for reactive airway disease, an asthma-like respiratory complication. Symptoms are similar to asthma. Namely, shortness of breath, coughing and wheezing. In most infants, such reactive airway disease subsides after six months, though in rare cases, reactive airway disease can affect children born with this syndrome until they are eight years old. These further complications due to brain or neurological damage and lung damage that may lead to shortened life expectancies that are related to those particular complications.

However, studies of babies that have severe meconium aspiration syndrome show a wide range of infant mortality rates – anywhere between 5-40%.