Before revision: Recognizing that labour pain, unlike that caused by injury or illness, is a purposeful process associated with uterine contractions underscores the effectiveness of natural pain relief techniques .
After revision: Labour pain may also be caused by vasoconstriction in the uterus, release of chemicals caused by muscle exertion, inflammation and ischemiaRecognizing that labour pain, unlike that caused by injury or illness, is a purposeful process associated with uterine contractions underscores the effectiveness of natural pain relief techniques .