Explain the physiological causes and consequences of labor pain during childbirth.

This slide explains why labor pain happens and how it affects the mother and baby. Labor pain is very intense. It's a mix of two types of pain: visceral pain (from organs like the uterus contracting and cervix opening) and somatic pain* (sharp pain from stretching tissues like the vagina and perineum). In early labor, the pain from uterine contractions and cervical changes travels through C fibres to the spinal cord* at levels T10 to L1. In late labor, the sharp pain from stretching and lack of oxygen to tissues (ischemic pain) travels through Aδ fibres to the spinal cord* at levels S2 to S4. This pain is not just unpleasant; it can be harmful. Severe pain can make the mother breathe too fast (hyperventilation), which can lead to too much carbon dioxide in her blood (hypercapnia). This can reduce oxygen to the baby (fetal hypoxaemia) and cause the baby's blood to become too acidic (metabolic acidosis*). 3 done, 2 left today. You're making progress.