Prevalence and risk factors for chronic pain following cesarean section: a prospective study

BACKGROUND Chronic post-surgical pain (CPSP) remains a major clinical problem which may be associated with impaired activities of daily life and decreased health-related quality of life. Although cesarean section is one of the most commonly performed operations, chronic pain after cesarean delivery has not been well-studied. The purpose of this prospective study was to assess the incidence and risk factors of chronic pain at 3, 6 and 12 months after cesarean delivery. METHODS We prospectively investigated preoperative demographic and psychological factors, intraoperative clinical factors, and acute postoperative pain in a cohort of 527 women undergoing cesarean section. The women were interviewed and completed pain questionnaires after 3, 6 and 12 months. Questions were about pain intensity, frequency, and location, as well as medical treatment and impact on daily living. RESULTS The incidence of CPSP at 3, 6 and 12 months after cesarean section was 18.3 %, 11.3 % and 6.8 %, respectively. Most of the women with CPSP experienced mild pain at rest. The incidence of moderate and severe pain on movement was high at 3 month, and then has a significant decrease at 6 and 12 months. CPSP had a negative influence on the activities of daily living. Independent predictors of CPSP at 3 months included higher average pain intensity on movement within 24 h postoperatively, preoperative depression, and longer duration of surgery. At 6 months, more severe pain during movement within 24 h of surgery and preoperative depression were predictive of pain persistence. And 12 months after surgery, only higher average pain score on movement within 24 h following cesarean section was found to be significant associated with CPSP. The three models all showed moderate discrimination and good calibration for the prediction of CPSP at 3, 6 and 12 months postoperatively. CONCLUSIONS CPSP was not rare in women undergoing cesarean section. Patients with more intense of acute postoperative pain on movement, preoperative depression, and longer surgical time had greater risk for CPSP following surgery.