Incidence of chronic postsurgical pain after caesarean delivery: a systematic review and meta-analysis.

Introduction: Chronic postsurgical pain is recognised increasingly as a complication of caesarean delivery, with implications for a large cohort of patients. As interest in this area has grown, there has been more primary research into both the incidence and severity of pain. We aimed to synthesise all available evidence to evaluate the rate, features and severity of chronic postsurgical pain following caesarean delivery and whether it has changed over time.

Methods: We performed a systematic review and meta-analysis of the incidence of chronic postsurgical pain at 3, 6 and 12 months after caesarean delivery and its characteristics, such as intensity and neuropathic pain. We also performed subgroup analyses based on study design quality, year of publication, country income and use of intrathecal morphine.

Results: A total of 48 studies were included in the meta-analysis. The pooled incidence of chronic postsurgical pain was 15.2% (95%CI 12.2-18.6%, I = 94%) at 3 months, 9.5% (95%CI 7.0-12.8%, I = 93%) at 6 months and 5.0% (95%CI 2.7-9.1%, I = 96%) at 12 months after caesarean delivery. Subgroup analyses showed a lower incidence of chronic pain in low- and middle-income countries than in high-income countries at 6 (6.8% vs. 12.3%, p = 0.028) and 12 months (1.3% vs. 7.6%, p < 0.001), but the incidence did not differ significantly in other subgroups. Most women with chronic pain had mild or moderate pain, and some had a neuropathic pain component.

Discussion: The incidence of chronic postsurgical pain after caesarean delivery falls between 3 and 12 months, appears to be stable over time and appears to be lower in low- and middle-income countries than in high-income countries. Future studies should consider using a consensus definition of chronic pain and assessment methods to reduce heterogeneity between studies.