What is the term for the passage of meconium in utero that contaminates amniotic fluid and is aspirated into the lungs after birth?

Answer: D — Meconium aspiration syndrome

Meconium aspiration syndrome describes what happens when a fetus passes meconium into the amniotic fluid and the newborn inhales it at birth. The inhaled meconium blocks small airways and causes chemical irritation and inflammation in the lungs, leading to respiratory distress and impaired gas exchange. This tends to occur in term or post-term babies or in stressed fetuses, and the newborn often has meconium-stained amniotic fluid and rapid, labored breathing after birth. On imaging, the lungs may show patchy, irregular infiltrates with possible hyperinflation and air leaks. This condition is different from respiratory distress syndrome, which is mainly due to surfactant deficiency in preterm infants; transient tachypnea of the newborn involves delayed clearance of fetal lung fluid, not meconium, and neonatal hepatitis refers to liver-related issues.