Final answer:
If the baby is crowning and the amniotic sac has not yet ruptured, you should wait for the amniotic sac to rupture naturally.
Step-by-step explanation:
During childbirth, if the baby is crowning and the amniotic sac has not yet ruptured, you should wait for the amniotic sac to rupture naturally. This typically happens at the end of the dilation stage in response to the pressure from the baby's head entering the birth canal. It is important to allow the amniotic sac to rupture on its own because it helps protect the baby and acts as a cushion during the birth process.