Relief of low back pain in labor by using intracutaneous nerve stimulation (INS) with sterile water papules.

Eighty-three women experiencing low back pain in the 1st stage of labor were given intracutaneous nociceptive stimulation (INS) by means of sterile water papules injected intracutaneously over sacrum. There was instant and complete relief of the low back pain in all but 6 women, this effect lasting in many cases as long as 3 h, after which INS could be repeated. A reduction in total pain-score from 6.05 to 2.92 was seen after 1 hour with no further analgesia given, and half the women required no further analgesia during the 1st stage. The method was well tolerated and 67 of the 83 women said they would like to have INS analgesia for their next delivery. Possible mechanisms behind the analgesic effect of INS are discussed.