Definition of Meconium aspiration syndrome:

Meconium is the first feces (stool) of the newborn. Meconium aspiration syndrome is when a serious condition in which a newborn breathes a mixture of meconium and amniotic fluid into the lungs around the time of delivery.

Causes, incidence, and risk factors:

Meconium aspiration syndrome is a leading cause of severe illness and death in the newborn. The possibility of inhaling meconium occurs in about 5-10% of births. It typically occurs when the fetus is stressed during labor, especially when the infant is past its due date.

Stress during labor can cause increased movement of the infant's intestines and relaxation of the anal sphincter, causing meconium to pass into the surrounding amniotic fluid. If the infant breathes while still in the uterus or while still covered by this fluid after birth, the mixture can enter the lungs and partially or completely block the infant's airways.

Risk factors include:

• Fetal distress
• Decreased oxygen to the infant while in the uterus
• Diabetes in the pregnant mother
• Difficult delivery
• High blood pressure in the pregnant mother