children s health issues
Meconium Aspiration Syndrome
Introduction
Meconium aspiration syndrome is trouble breathing (respiratory distress) in a newborn who has breathed (aspirated) a dark green, sterile fecal material called meconium into the lungs before or around the time of birth. Even though fetuses do not eat, their intestines contain a sterile substance called meconium. Fetuses sometimes pass meconium into the amniotic fluid before birth, either normally or in response to stress, such as a lack of oxygen. Stress may cause fetuses to gasp reflexively, thus inhaling amniotic fluid containing meconium into their lungs. Affected newborns have bluish or gray skin and/or lips, rapid and labored breathing, and can make a grunting sound when breathing out. The diagnosis is based on seeing meconium in the amniotic fluid at birth, along with trouble breathing and abnormal chest x-ray results. Affected newborns require supplemental oxygen and may require assistance with a ventilator. Most affected newborns survive, but the syndrome can be fatal if severe. (See also Overview of General Problems in Newborns .) is the dark green, sterile fecal material that is produced in the intestine before birth. Meconium is usually passed after birth when newborns start to feed, but sometimes it is passed into the amniotic fluid before or around the time of birth. Passage of meconium may be normal before birth, particularly just before or after the due date. But sometimes meconium passage occurs in response to stress, such as by an infection or by an inadequate level of oxygen in the blood. Although meconium passage may be normal in a term or Postterm Newborns , it is never normal for there to be meconium noted at the delivery of a occurs when stress (such as infection or low oxygen levels) causes the fetus to take forceful gasps, so that the amniotic fluid containing meconium is breathed in (aspirated) and deposited into the lungs. After delivery, the aspirated meconium may block the newborn's airways and cause regions of the lungs to collapse. Sometimes airways are only partially blocked, allowing air to reach the parts of the lung beyond the blockage but preventing it from being breathed out. Thus, the involved lung may become over-expanded. When a portion of the lung continues to over-expand, it can rupture and then collapse the lung. Air may then accumulate within the chest cavity around the lung ( Pneumothorax in the Newborn ). Meconium aspirated into the lungs also causes inflammation of the lungs (pneumonitis) and increases the risk of lung infection. Newborns with meconium aspiration syndrome are also at increased risk of Persistent Pulmonary Hypertension of the Newborn . 