Which scenario contributes to meconium aspiration?

• A. The baby becomes hypoxic with meconium in amniotic fluid
• B. The baby cries immediately after birth
• C. The infant is delivered via cesarean without labor
• D. The mother uses caffeine in pregnancy

Answer: (A)

Meconium aspiration risk rises when fetal distress causes the fetus to pass meconium into the amniotic fluid and then inhale it during birth. When the baby becomes hypoxic, vagal stimulation can lead to relaxation of the anal sphincter and passage of meconium into the amniotic fluid. If the newborn then inhales or aspirates this meconium-stained fluid, it can obstruct the airways and trigger inflammatory lung injury (meconium aspiration syndrome), potentially contributing to respiratory distress and—but not always—persistent pulmonary hypertension.

In the scenario described, fetal hypoxia with meconium present in the amniotic fluid indicates this pathophysiology is in play, making meconium aspiration more likely. The other options don’t reflect this risk: crying immediately after birth suggests good airway adaptation; delivery by cesarean without labor reduces exposure to meconium-stained fluid; and maternal caffeine use isn’t a recognized direct driver of MAS.