Final answer:
Crowning occurs during the second stage of labor when the baby’s head becomes visible at the vaginal opening, indicating that the birth of the baby is near.
Step-by-step explanation:
The term crowning in the context of childbirth refers to the moment during labor when the baby’s head or the presenting part starts to become visible at the vaginal opening. This is a part of the second stage of labor, known as the expulsion of the newborn, indicating that delivery is imminent. Crowning occurs after the cervix is fully dilated to 10 centimeters, allowing the baby to move down the birth canal. This stage concludes with the delivery of the baby, after which the third stage, delivery of the placenta and fetal membranes, takes place.