Before birth, the fetal monitor may show a slow heart rate. During delivery or at birth, meconium can be seen in the amniotic fluid and on the infant.
The infant may need help with breathing or heartbeat right after birth, and may have a low Apgar score.
The health care team will listen to the infant's chest with a stethoscope and may hear abnormal breath sounds, especially coarse, crackly sounds.
A blood gas analysis will show low (acidic) blood pH, decreased oxygen, and increased carbon dioxide.
A chest x-ray may show patchy or streaky areas in the infant's lungs.