Understanding maternal pain and psychological vulnerabilities associated with the development of sub-acute pain after childbirth.

BACKGROUND

Current research primarily concentrates on acute and chronic postpartum pain, while sub-acute pain after childbirth (SAPC) remains a significant but often under-recognized health concern. We determined if pain and psychological vulnerabilities, obstetric factors, and analgesic choices were associated with the development of SAPC.

METHODS

We included women with singleton pregnancy. Pain and psychological vulnerabilities were assessed using validated questionnaires (Angle Labor Pain Questionnaire (A-LPQ), Central Sensitization Inventory (CSI), Edinburgh Postnatal Depression Scale (EDPS), Fear Avoidance Components Scale (FACS), Pain Catastrophizing Scale (PCS), Perceived Stress Scale (PSS), State Trait Anxiety Inventory (STAI)). The primary outcome of SAPC, defined as having postpartum pain lasting for ≥4 weeks, was followed up at 6 to 10 weeks postpartum with online survey.

RESULTS

Of the 881 patients recruited, 816 completed the postpartum follow-up, with 99 (12.1%) patients having developed SAPC. Having higher CSI score (adjusted odds ratio (aOR) 1.03, 95%CI 1.01-1.04), increased number of pain relief administrations (aOR 1.55, 95%CI 1.23-1.95), use of artificial rupture of membrane and oxytocic for labor induction (aOR 2.72, 95%CI 1.51-4.91), greater volume of blood loss during delivery (every 10-mL increase; aOR 1.02, 95%CI 1.01-1.03), having had third-degree tear during delivery (aOR 4.12, 95%CI 1.28-13.27) and greater infant weight (aOR 1.15, 95%CI 1.02-1.30) were independently associated with greater risk of SAPC. The use of prostin for labor induction was protective against the risk of SAPC (aOR 0.56, 95%CI 0.34-0.93) (Area under the curve (AUC) = 0.73).

CONCLUSION

Our center's multivariable model demonstrates moderate predictive performance and may inform the future development and refinement of predictive tools to identify patients at increased risk of SAPC, thereby supporting more timely monitoring and early interventions for postpartum pain management.

TRIAL REGISTRATION: This study was registered on clinicaltrials.gov registry (NCT03167905) on 30/05/2017.