Final answer:
An epidural block is usually administered to a birthing individual when the cervix is dilated to about 4 cm. This facilitates pain management during the subsequent stages of labor and delivery.
Step-by-step explanation:
An epidural block is often administered during the first stage of labor, when the cervix is sufficiently dilated to allow for the progression of labor and eventual delivery of the baby. Generally, the minimum dilation required for an epidural block can vary, but it is commonly recommended when the cervix is dilated to about 4 cm.
The cervix must fully dilate to 10 cm for the baby to pass through during the second stage of labor, which involves the expulsion of the baby from the uterus. The third stage is characterized by the passage of the placenta after the baby's birth.