Which of the following is a sign that the second stage of labor has begun?

The second stage of labor is defined by the onset of the urge to push, which occurs after the cervix is fully dilated. This stage involves the descent and birth of the baby. When a laboring person experiences a strong urge to push, it indicates that the baby is beginning to move down the birth canal, signaling the transition from the first stage of labor (which focuses on cervical dilation) to the active phase of the second stage.

The complete dilation of the cervix signifies that the first stage of labor has concluded but does not itself indicate the beginning of the second stage. Fetal heart rate stabilization is a reassuring sign during labor but does not specifically indicate the start of the second stage. A decreased bloody show is not connected to the physiological changes that signal the commencement of the second stage; rather, it may indicate other factors during labor progression. Thus, the urge to push is a definitive sign that the second stage has begun and is a critical physiological response in the labor process.