Planned interim analysis-no statistical significance for the primary outcome.

Pain following Cesarean delivery remains the most common post-operative complaint, and the provision of effective and safe analgesia is very important. Pain can impede the mother's ability to mobilise, and to care for and breastfeed her newborn baby.

Pulsed electromagnetic field (PEMF) devices have been used in various clinical settings, especially after plastic surgeries, to reduce postoperative swelling and pain, as well as to accelerate wound repair. PEMF therapy is simple to use, cost-effective and has no known side effects.

Despite advances in post-operative analgesia, pain relief and maternal satisfaction remain inadequate in some patients. Improving the quality of post-Cesarean analgesia while limiting undesirable side effects will enhance maternal satisfaction and reduce the risk of post-operative complications.

The investigators hypothesize that the continuous use of a PEMF device for 48 hours after Cesarean delivery will result in decreased post-operative pain scores on movement at 48 hours.

Currently, at our institution, analgesic regimens are multimodal, in that they combine analgesic drugs with differing mechanisms of action, with the aim of producing effective analgesia while minimising adverse effects. They include opioid drugs, administered both neuro-axially and systemically, as well as paracetamol and non-steroidal anti-inflammatory drugs (NSAIDs). Opioids, while effective, have significant adverse effects, including sedation, nausea, vomiting and constipation. Non-steroidal anti-inflammatory drugs (NSAIDs) can reduce opioid consumption, but also have side effects, and are contra-indicated in a significant number of patients. Therefore there remains considerable scope to improve post-Cesarean analgesia.

Pulsed electromagnetic field (PEMF) technology relieves edema, inflammation and pain by stabilizing leaking cell membranes. The short bursts of electrical current do not produce heat or interfere with nerve or muscle function. The pulsed energy drives out edematous fluid along with by-products of the damaged tissue, which reduces swelling and helps re-establish cell-cell communication. The device is easily applied over the wound dressing, and has no known side effects for either the mother or the infant.

As the rate of Cesarean delivery continues to increase, and there remain significant problems with current analgesic regimens, the use of pulsed electromagnetic field therapy has the potential to considerably improve acute and chronic post-Cesarean pain management, and lead to a widespread change in clinical practice.

Inclusion Criteria:

• 18 years or older
• full term singleton pregnancy
• undergoing elective cesarean delivery

Exclusion Criteria:

• Patients who have refused, are unable to give or have withdrawn consent
• Patients unable to communicate fluently in English
• Patients with American Society of Anesthesiologists (ASA) classification of 3 or greater
• Patients with chronic pain, or neuropathic analgesic drugs
• Patients in use of antidepressant and psychotropic drugs
• Patients with a history of opioid or intravenous drug abuse
• Patients with known allergy or contra-indication to any other drugs used in this trial
• Patients who have refused spinal anesthesia, or those in whom it is contra-indicated
• Patients with a history of previous cesarean delivery and persistent pain