The incidence of chronic post-surgical pain (CPSP) after caesarean section (CS) is reported
to be as high as 18%, reflecting it to be a significant clinical problem. Studies related to
prevention of progression of acute post-CS pain to its chronicity are sparse. Current
guidelines on post-CS analgesia recommend the use of intrathecal (IT) opioids to spinal
anaesthesia for improved post-CS pain relief. Despite its frequent use, studies related to
the IT morphine use and its association with post-CS chronic pain are lacking.

A recent prospective observation study revealed a significant reduction in persistent pain
after CS when IT morphine was used as an adjuvant to spinal anaesthesia. However, there is no
any randomized controlled trial (RCT) that has explored this association to date. We
hypothesized that spinal morphine would reduce the incidence of persistent pain after CS.