Meconium aspiration syndrome (also referred to as meconium aspiration) occurs when a newborn inhales a mixture of meconium and amniotic fluid during labor and delivery.
Meconium is the material that fills the fetal intestinal tract during pregnancy and is formed from ingested amniotic fluid and dead intestinal cells. Although it is sterile, inhaled meconium is highly irritating to the lung when the infant takes its first breaths. It can cause a partial or complete blockage of the baby's airways when exhaling, making it difficult to breathe.
Meconium alters the amniotic fluid, reducing antibacterial activity and subsequently increasing the risk of perinatal bacterial infection. Meconium-stained amniotic fluid occurs in 7 to 22% of term deliveries. In anywhere from 2% to more than a third of these deliveries, MAS can occur.
Aspiration induces 3 major pulmonary effects, which are airway obstruction, surfactant dysfunction, and chemical pneumonitis.
One of the techniques used in preventing this syndrome in children is amnioinfusion. This technique involves infusing saline, though a small synthetic tube into the amniotic cavity of women in labour who show heavy meconium.
Amnioinfusion is intended to reduce the risk of MAS by diluting the meconium.
A recent study has revealed that amnioinfusion, the infusion of saline into the uterus, does not reduce the risk of meconium aspiration syndrome (MAS), as previously believed.
The rigorous study methods and international scope of this trial provides very strong evidence against the use of amnioinfusion, and the results are likely to have a major impact on childbirth practices around the world.