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Efficacy and safety of nalbuphine vs. pethidine in oocyte retrieval: a non-inferiority, double-blinded, randomized controlled trial

Em-Eam P, Thepsoparn M, Suebthawinkul C

Frontiers in reproductive health, 2026

94 participants

Abstract

Objective: The purpose of this study was to evaluate the efficacy and safety of Nalbuphine compared to Pethidine for pain relief during oocyte retrieval.

Methods: In a double-blinded, non-inferiority randomized controlled trial (n = 94), participants were randomized equally into two groups. The intervention group received 10 mg intravenous Nalbuphine combined with 5 mg of Midazolam, while the control group received 50 mg intravenous Pethidine with 5 mg of Midazolam. The primary outcome was pain score measured immediately postoperatively using a visual analogue scale. Secondary outcomes included pain score at 2 and 6 h postoperatively, operator score for patient cooperation, vital signs, number of total oocytes and metaphase II (MII) oocytes retrieved, operative time, recovery time, side effects, and need for rescue analgesia.

Results: Nalbuphine demonstrated non-inferiority to Pethidine for pain control at 0 h postoperatively, with a mean difference of 0.52 (95% CI: -0.40 to 1.44). Similar findings were observed at 2 h (mean difference -0.46; 95% CI: -1.30 to 0.38), while at 6 h Nalbuphine showed significantly lower pain scores (mean difference -1.28; 95% CI: -2.15 to -0.41). No significant differences were observed between groups in operator score, recovery time, or rescue analgesia requirements. The number and quality of oocytes retrieved were not affected by the analgesic regimen. Side effects such as nausea, vomiting, dizziness, and tachycardia were compared and showed…

How strong is the evidence?

Evidence Hub reads this as a randomized trial, done in people. Its evidence level is 2 of 5 (High · randomized trial). Randomized trials of a reasonable size are the strongest single-study design. Reported size: 94 participants or records.

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