A spinal block can be given using a much thinner needle than an epidural block in the same place on the back where an epidural block is placed. The spinal block uses a much smaller dose of the drug, and it is injected into the sac of spinal fluid below the level of the spinal cord. Once this drug is injected, pain relief occurs right away.
A spinal block usually is given only once during labor, so it is best suited for pain relief during delivery. A spinal block with a much stronger medication (anesthetic, not analgesic) is often used for a cesarean delivery. It also can be used in a vaginal birth if the baby needs to be helped out of the birth canal with forceps or by vacuum extraction.