During child birth

1. Meconium Aspiration

2. INCIDENCE
oMeconium-stained amniotic fluid is found in 10-15% of births
oUsually occurs in term or post-term infants
oMeconium aspiration syndrome (MAS) develops in 5% of such infants;
30% require mechanical ventilation, and 3-5% die
oUsually, but not invariably, fetal distress and hypoxia occur before the
passage of meconium into amniotic fluid
oThe infants are meconium stained and may be depressed and require
resuscitation at birth

3. pathophysiology
oAcute or chronic hypoxia or vagal stimulation may result in the
passage of meconium in-utero.
oSubsequent gasping in-utero or at birth can result in aspiration of
amniotic fluid contaminated by meconium.
oMeconium aspiration before, during or after birth may have a
profound effect on the neonatal respiratory system, causing:
• 1. Mechanical obstruction
• 2. Chemical inflammation
• 3. Diminished production of surfactant as well as inactivation

4. Risk factors
1. Post term delivery
2. Small for gestational age neonates
3. Intrauterine growth restriction
4. Ante/intrapartum distress and hypoxia
5. Maternal complications causing impaired uteroplacental blood flow
a. Pregnancy Induced Hypertension (PIH)
b. Chronic hypertension
c. Maternal tobacco use
d. Chronic maternal respiratory or cardiovascular disease
6. Intrapartum conditions causing impaired uteroplacental blood flow (cord
compression, oligiohydramnios)

5. Clinical Manifestations
oEither in utero or with the 1st breath, thick, particulate meconium is
aspirated into the lungs.
oSmall airway obstruction may produce respiratory distress within the
1st hours, with tachypnea, retractions, grunting, and cyanosis in
severely affected infants
oPartial obstruction of some airways may lead to
pneumomediastinum, pneumothorax
o Overdistention of the chest may be prominent
oUsually improves within 72 hr, but when its course requires assisted
ventilation, it may be severe with a high risk for mortality.

6. Clinical Manifestations
oTachypnea may persist for many days or even several weeks
oTypical chest roentgenogram is characterized by patchy infiltrates,
coarse streaking of both lung fields, increased anteroposterior
diameter, and flattening of the diaphragm
oA normal chest roentgenogram in an infant with severe hypoxemia
and no cardiac malformation suggests the diagnosis of pulmonary
hypertension

7. Prevention
oRisk of meconium aspiration may be decreased by rapid identification
of fetal distress and initiation of prompt delivery
oRoutine intrapartum nasopharyngeal suctioning in infants with
meconium-stained amniotic fluid does not reduce the risk for MAS

8. Treatment
oRoutine intubation to aspirate the lungs of vigorous infants born
through meconium-stained fluid is not effective in reducing MAS
oDepressed infants (those with hypotonia, bradycardia, or decreased
respiratory effort) may benefit from endotracheal intubation and
suction to remove meconium from the airway before the 1st breath in
the delivery room
oTreatment of MAS includes supportive care and standard
management for respiratory distress

9. Prognosis
oThe mortality rate of meconium-stained infants is higher than that of
non-stained infants
oResidual lung problems are rare but include symptomatic cough,
wheezing, and persistent hyperinflation for up to 5-10 yr.
oUltimate prognosis depends on the extent of CNS injury from
asphyxia and the presence of associated problems such as pulmonary
hypertension

10. Thank you