Although the pathway for fetal defecation exists, this does not usually occur. In most cases the first defecation occurs postnatally; the bile-stained fecal matter is called meconium. In 10 15% of all deliveries, the neonate's amniotic fluid is meconium-stained, indicating some amount of in utero defecation. Even though about one-third of such neonates will have some meconium in their lungs, on...

Meconium aspiration syndrome (MAS) is a common cause of severe respiratory distress in term infants, with an associated highly variable morbidity and mortality. MAS results from aspiration of meconium during intrauterine gasping or during the first few breaths. The pathophysiology of MAS is multifactorial and includes acute airway obstruction, surfactant dysfunction or inactivation, chemical pn...

The first urine passed by a newborn infant who has inhaled meconium or meconium-stained amniotic fluid often contains a dark-coloured water-soluble substance, recognisable spectrophotometrically by an absorption band at about 405 nm. Spectrophotometric analysis of the first urine can in this way be used to diagnose preceding meconium aspiration.

Earlier work form this laboratory showed that exposure of alveolar epithelial cells (AECs) to meconium caused significant cell detachment and that meconium-induced detachment of cells was prevented by a protease inhibitor cocktail. Therefore, it was hypothesized that protease inhibitors might protect AEC monolayers against meconium-induced collapse of epithelial barrier function both in vitro a...

BACKGROUND Surfactant dysfunction due to inhibition is involved in the pathophysiology of meconium aspiration syndrome. Dextran addition has been shown to reverse exogenous surfactant inactivation by meconium, but the precise mechanisms and the morphological correlate of this effect are yet unknown. Morphological surfactant analysis by transmission electron microscopy (TEM) and stereology allow...