Final answer:
The greatest risk to a newborn with meconium-stained amniotic fluid is meconium aspiration syndrome, which can cause serious respiratory difficulties and infections. It necessitates prompt medical attention and aspiration of the newborn's airways to prevent the inhalation of meconium.
Step-by-step explanation:
The greatest risk to a newborn with meconium-stained amniotic fluid is meconium aspiration syndrome (MAS), where meconium is inhaled into the lungs, potentially causing serious complications such as obstruction of the airways, alveolar collapse, interference with surfactant function, pulmonary inflammation, pulmonary hypertension, and increased vulnerability to pulmonary infections, including pneumonia. The condition often follows fetal distress, which can be signaled by the passage of meconium in the womb and may be due to factors such as maternal drug abuse, hypertension, or complications with the placenta. It is crucial for the obstetrician to aspirate the newborn's airways before the infant takes its first breath to minimize the risk of MAS.
During childbirth, when the amniotic sac ruptures, the presence of meconium can be observed if the fluid is greenish or yellowish instead of clear. In cases where meconium is present, obstetricians may perform blood gas tests and chest X-rays to confirm aspiration and listen to the lungs with a stethoscope for signs like coarse rattling sounds.