Which statement best describes the third stage of labor?

The third stage of labor is defined as the period after the baby is born and concludes with the delivery of the placenta. The correct statement accurately reflects that the placenta is expelled from the uterus during this stage. This process typically occurs within a few minutes to up to half an hour after the delivery of the infant. It is crucial as it helps to prevent complications such as postpartum hemorrhage.

The other options describe either earlier stages or events in the labor process. For instance, the complete delivery of the infant pertains to the second stage of labor, while the rupture of the amniotic sac usually happens in the first stage, often referred to as the "water breaking." The appearance of the infant's head is also a hallmark of the second stage of labor, signifying the crowning phase just before the baby is fully delivered. Hence, while these events are integral to the overall labor process, they do not describe the third stage accurately.