Persistent Pain After Cesarean Delivery - A Danish Multicenter Cohort Study

In Denmark, around 12,700 patients undergo Cesarean delivery (CD) annually, constituting approximately 20% of all childbirths in the country. Worldwide, the number is increasing each year, with more than 20 million CD performed annually.

Postoperative pain after CD is typically moderate to severe in intensity and still constitutes a significant challenge, balancing effective pain relief and potential side effects. Correlations between moderate to severe acute pain and the development of persistent pain after CD is still unclear.

Postsurgical persistent pain is a significant, often unrecognized clinical problem that causes distress and diminishes the quality of life for patients. Despite advances in understanding the factors contributing to persistent postsurgical pain and an increased focus on identifying patients at risk, the management and prevention of postsurgical persistent pain are still inadequate.

It is important to gain further insights into this population, and we have a unique opportunity to do so by following the national cohort from the ongoing Danish multicenter cohort study on pain after cesarean section (ClinicalTrials.gov Identifier: NCT06012747) over an extended follow-up period.

This involves continued prospective registration of Patient-Reported Outcome Measures (PROM) collected by SMS-based questionnaires in the months and years after the CD, thereby investigating the occurrence of both acute and persistent pain after CD.

The outcomes are focused on pain levels, the impact of pain on physical function and neuropathic pain characteristics in the months and years following the CD. The study also aims to explore the relationship between persistent and acute pain.

Study Overview

• Status: Completed
• Conditions: Chronic Pain; Cesarean Section Complications; Cesarean Section; SMS; Cesarean Delivery; Questionnaire; Persistent Pain

Detailed Description

The Study Protocol is attached in full-text (Study Documents).

• Study Type: Observational
• Enrollment (Actual): 477

Contacts and Locations

Study Locations

• Denmark
  • Hillerød, Denmark, 3400
    • Department of Anesthesiology, Copenhagen University Hospital, North Zealand Hillerød

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: N/A

• Sampling Method: Non-Probability Sample

Study Population

Patients, aged > 18 years, who undergo planned cesarean delivery under spinal anesthesia.

Description

Inclusion Criteria:

• Patients who, after participating in the Danish multicenter cohort study on pain after cesarean delivery (ClinicalTrials.gov Identifier: NCT06012747), consent to continue to receive questionnaires about persistent pain.
• Planned cesarean delivery in spinal anesthesia
• Patients who speak and read Danish
• Patients with a smartphone that can receive an SMS with a link to a questionnaire that can be opened online.

Exclusion Criteria:

• <18 years of age

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Persistent pain	The percentage of patients reporting pain equivalent to an NRS score > 3 after 6 months	after 6 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Severe pain during the last 24 hours.	NRS 0-10	Assessments are conducted at 5 weeks, 2, 3, 6, and 12 months, and after that every 6 months until 3 years after surgery.
Severe pain at rest during the last 24 hours.	NRS 0-10	Assessments are conducted at 5 weeks, 2, 3, 6, and 12 months, and after that every 6 months until 3 years after surgery.
Use of analgesic medication in the past week due to pain (Paracetamol, Non-Steroidal Anti-Inflammatory Drug, opioid).	Yes/No	Assessments are conducted at 5 weeks, 2, 3, 6, and 12 months, and after that every 6 months until 3 years after surgery.
Pain's affect on daily activities	1-5: Not at all, a little, to some extent, to a great extent, cannot do due to pain.	Assessments are conducted at 5 weeks, 2, 3, 6, and 12 months, and after that every 6 months until 3 years after surgery.
Pain's affect on engaging in strenuous physical activity.	1-6: Not at all, a little, to some extent, to a great extent, cannot do due to pain, I don't know - I haven't tried.	Assessments are conducted at 5 weeks, 2, 3, 6, and 12 months, and after that every 6 months until 3 years after surgery.
Pain's affect on meeting the infant's needs.	1-5: Not at all, a little, to some extent, to a great extent, cannot do due to pain.	Assessments are conducted at 5 weeks, 2, 3, 6, and 12 months, and after that every 6 months until 3 years after surgery.
Pain's affect on sleep.	1-4: Not at all, a little, to some extent, to a great extent.	Assessments are conducted at 5 weeks, 2, 3, 6, and 12 months, and after that every 6 months until 3 years after surgery.
Pain's affect on mood.	1-4: Not at all, a little, to some extent, to a great extent.	Assessments are conducted at 5 weeks, 2, 3, 6, and 12 months, and after that every 6 months until 3 years after surgery.
Pain/discomfort when sitting down or standing up from a chair.	1-5: Not at all, a little, to some extent, to a great extent, cannot do due to pain.	Assessments are conducted at 5 weeks, 2, 3, 6, and 12 months, and after that every 6 months until 3 years after surgery.
Pain/discomfort when walking on stairs.	1-5: Not at all, a little, to some extent, to a great extent, cannot do due to pain.	Assessments are conducted at 5 weeks, 2, 3, 6, and 12 months, and after that every 6 months until 3 years after surgery.
Pain/discomfort when getting in or out of bed.	1-5: Not at all, a little, to some extent, to a great extent, cannot do due to pain.	Assessments are conducted at 5 weeks, 2, 3, 6, and 12 months, and after that every 6 months until 3 years after surgery.
Pain/discomfort when carrying the infant.	1-5: Not at all, a little, to some extent, to a great extent, cannot do due to pain.	Assessments are conducted at 5 weeks, 2, 3, 6, and 12 months, and after that every 6 months until 3 years after surgery.
Pain/discomfort when sitting up for less than 30 minutes.	1-5: Not at all, a little, to some extent, to a great extent, cannot do due to pain.	Assessments are conducted at 5 weeks, 2, 3, 6, and 12 months, and after that every 6 months until 3 years after surgery.
Pain/discomfort if sitting up for more than 30 minutes.	1-6: Not at all, a little, to some extent, to a great extent, cannot do due to pain, I don't know - I haven't tried.	Assessments are conducted at 5 weeks, 2, 3, 6, and 12 months, and after that every 6 months until 3 years after surgery.
Pain/discomfort when moving around at home.	1-5: Not at all, a little, to some extent, to a great extent, cannot do due to pain.	Assessments are conducted at 5 weeks, 2, 3, 6, and 12 months, and after that every 6 months until 3 years after surgery.
Pain/discomfort if walking for more than 30 minutes.	1-6: Not at all, a little, to some extent, to a great extent, cannot do due to pain, I don't know - I haven't tried.	Assessments are conducted at 5 weeks, 2, 3, 6, and 12 months, and after that every 6 months until 3 years after surgery.
Pain/discomfort when bending down.	1-5: Not at all, a little, to some extent, to a great extent, cannot do due to pain.	Assessments are conducted at 5 weeks, 2, 3, 6, and 12 months, and after that every 6 months until 3 years after surgery.
Pain/discomfort during or after sexual intercourse.	1-7: Not at all, a little, to some extent, to a great extent, cannot do due to pain, I don't know - I haven't tried, I prefer not to answer.	Assessments are conducted at 5 weeks, 2, 3, 6, and 12 months, and after that every 6 months until 3 years after surgery.
Pins and needles, tingling or stabbing sensations in or around the area of the surgery?	Yes/No	Assessments are conducted at 5 weeks, 2, 3, 6, and 12 months, and after that every 6 months until 3 years after surgery.
Electric shock like sensation or jabbing feelings in the skin area in or around the area of the surgery?	Yes/No	Assessments are conducted at 5 weeks, 2, 3, 6, and 12 months, and after that every 6 months until 3 years after surgery.
Heat or burning sensations in or around the area of the surgery?	Yes/No	Assessments are conducted at 5 weeks, 2, 3, 6, and 12 months, and after that every 6 months until 3 years after surgery.
Pain caused by the lightest of touches in or around the area of the surgery?	Yes/No	Assessments are conducted at 5 weeks, 2, 3, 6, and 12 months, and after that every 6 months until 3 years after surgery.
Pain caused by cold temperatures in or around the area of surgery?	Yes/No	Assessments are conducted at 5 weeks, 2, 3, 6, and 12 months, and after that every 6 months until 3 years after surgery.

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Recall of acute pain at 12 and 24 hours after CD	Exploratory	Asked 12 months after CD.
Percentage of patients experiencing pain with an NRS > 3	Exploratory	1, 2, 3, and 12 months, as well as 1,5; 2; 2,5 and 3 years after cesarean delivery.
Association between severe acute pain (NRS > 6) during the first 24 hours and the occurrence of persistent pain at 6 and 12 months after CD.	Exploratory	12 months
Prevalence of chronic pain before pregnancy.	Exploratory	6 months
Prevalence of chronic pain before pregnancy and its association with the development of persistent pain	Exploratory	1, 2, 3, and 12 months, as well as 1,5; 2; 2,5 and 3 years after cesarean delivery.
6. Association between uterine exteriorization versus in situ repair in CD and the occurrence of persistent pain	Exploratory	1, 2, 3, and 12 months, as well as 1,5; 2; 2,5 and 3 years after cesarean delivery.

Collaborators and Investigators

• Sponsor: Nordsjaellands Hospital
• Investigators: Principal Investigator: Patricia Duch, MD, University Hospital of Copenhagen, Hillerød, Denmark; Study Director: Helene Nedergaard, MD, Ph.D, University Hospital of Southern Denmark, Kolding; Study Director: Christoffer Jørgensen, Dr. Med., University Hospital of Copenhagen, Hillerød, Denmark; Study Chair: Kim Wildgaard, MD, Ph.d., University Hospital of Copenhagen, Herlev, Denmark

Study record dates

Study Major Dates

• Study Start (Actual): September 1, 2023
• Primary Completion (Actual): June 10, 2025
• Study Completion (Actual): September 1, 2025

Study Registration Dates

• First Submitted: January 8, 2024
• First Submitted That Met QC Criteria: January 30, 2024
• First Posted (Actual): February 8, 2024

Study Record Updates

• Last Update Posted (Estimated): September 3, 2025
• Last Update Submitted That Met QC Criteria: September 2, 2025
• Last Verified: September 1, 2025

More Information

Terms related to this study

• Keywords: chronic pain; cesarean section; post operative pain; acute on chronic pain; cesarean delivery; persistent pain; Danish cohort; SMS questionnaire
• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Postoperative Complications; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Pain, Postoperative; Chronic Pain
• Other Study ID Numbers: 101 (Other Identifier: Hamilton Integrated Research Ethics Board)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No