Which of the following is associated with meconium-stained amniotic fluid during labor?

• A. Transition
• B. Prematurity
• C. Fast labor
• D. Fetal distress

Answer: (D)

Meconium-stained amniotic fluid during labor most strongly signals fetal distress. When the fetus experiences hypoxia or stress, increased vagal stimulation stimulates intestinal motility and relaxation of the anal sphincter, leading to passage of meconium into the amniotic fluid. This meconium can then be inhaled or aspirated into the lungs around birth, risking meconium aspiration syndrome and respiratory difficulties in the newborn. While meconium in the fluid can occur in other scenarios, the link to fetal hypoxia makes fetal distress the best explanation. The other options don’t fit as a typical cause or marker during labor: transition happens after birth, prematurity and fast labor are not specifically tied to meconium passage in the fluid.