Meconium aspiration syndrome

[Sarah]

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 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.)
Meconium 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 postmature fetus, it is never normal for there to be meconium noted at the delivery of a premature baby. Meconium passage in a premature baby most often means the baby developed an infection while in the womb.
Meconium aspiration syndrome 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 (aspirated) in and deposited into the lungs. After delivery, the aspirated meconium may block the newborn

[Monty]

Intrapartum meconium aspiration can cause inflammatory pneumonitis and mechanical bronchial obstruction, causing a syndrome of respiratory distress. Findings include tachypnea, rales and rhonchi, and cyanosis or desaturation. Diagnosis is suspected when there is respiratory distress after delivery through meconium-containing amniotic fluid and is confirmed by chest x-ray. Infants with respiratory distress are often intubated and placed on mechanical ventilation. Treatment of severely affected infants with surfactant decreases the need for extracorporeal membrane oxygenation but does not affect mortality (1, 2). Prognosis depends on the underlying physiologic stressors.
(See also Overview of Perinatal Respiratory Disorders.)
Extensive physiologic changes accompany the birth process, sometimes unmasking conditions that posed no problem during intrauterine life. For that reason, a person with neonatal resuscitation skills must attend each birth. Gestational age and growth parameters help identify the risk of neonatal pathology.