Final answer:
An epidural shot is the most common form of pain relief during childbirth, administered to reduce the pain caused by myometrial hypoxia during uterine contractions.
Step-by-step explanation:
An epidural (upon the dura mater) shot is the most popular form of pain relief during childbirth. The epidural is administered into the epidural space surrounding the dura mater of the spine to provide anesthesia during labor. Labor progresses through several stages starting with cervical dilation, the expulsion of the newborn, and concluding with the afterbirth stage. The pain experienced during labor is often due to myometrial hypoxia during uterine contractions, which occur as the myometrium and cervix stretch. An epidural can help manage this pain, allowing for a more comfortable birthing experience.