Cutting the bottom of the baby is what we usually call an episiotomy, and it is not a routine obstetric operation. If there are no special circumstances during labor, an episiotomy will not be done easily, and it will only be done when there are special circumstances. For example, if the perineum is overly tense during labor, a severe perineal tear can easily occur, or if the fetus is relatively large, an episiotomy is needed to avoid a severe perineal laceration. In other cases, when the mother or the fetus is in an emergency situation and the labor has to end as soon as possible, an episiotomy may be performed to prepare for the following assisted delivery.