Pain and adverse effects after caesarean delivery: A nationwide prospective cohort study

BACKGROUND: Caesarean delivery can cause severe postoperative pain that can adversely affect recovery. However, balancing effective pain management while minimising the risk of opioid-related adverse effects remains a clinical challenge. OBJECTIVE: In this nationwide study, we aimed to describe the incidence and severity of acute pain and adverse effects of opioid administration following the first hours and days after elective caesarean delivery. DESIGN: Prospective nationwide Danish multicentre cohort study. SETTING: All maternity hospitals in Denmark over a 6-month period during 2023-2024. PATIENTS: Patients having elective caesarean delivery. INTERVENTION: Patient-reported outcomes on pain [Numeric Rating Scale (NRS) 0 to 10] and opioid-related adverse effects were collected using text message-based questionnaires via smartphone contact at 6, 12, 18, 24, and 48 h postcaesarean delivery, and on days 7 and 30. MAIN OUTCOME MEASURES: The two primary outcomes were pain on mobilisation at 24 h, and adverse events of opioid administration (namely, nausea, vomiting, dizziness, pruritus and urinary retention) within 24 h. RESULTS: In total, 738 patients were included from 19 of 22 Danish maternity hospitals. Median [IQR] pain during mobilisation 24 h postcaesarean delivery was NRS 5 [3 to 6], peaking at 12 h postoperatively with NRS 6 [5 to 8]. Median oral morphine equivalents (OME) within the first 24 h were 30 [20 to 50] mg. Adverse effects peaked 6 h postoperatively, with pruritus being the most common. Within the first 24 h 59 [95% confidence interval (CI), 55 to 63]% reported severe pain (NRS ≥ 7) and 55 (95% CI, 51 to 59)% reported opioid-related adverse effects. CONCLUSIONS: In Denmark, severe pain after caesarean delivery affects more than half the patients within the first 24 h, peaking at 12 h. Additionally, most report moderate or severe opioid-related adverse effects. These results underscore the need to optimise pain management, particularly during the first 24 h when pain is highest. The results can inform both patients and healthcare providers about expected pain trajectories and serve as the foundation for future research, and guide interventions. TRIAL REGISTRATION: www.clinicaltrials.gov , NCT06012747.