Effect of Nalbuphine Combined with Ropivacaine on Analgesia and Prolactin after Cesarean Section

Objective. To investigate the impact in women of nalbuphine and ropivacaine transverse abdominis plane block (TAPB) on pain relief and prolactin levels after cesarean section. Methods. Sixty pregnant women who underwent cesarean section and joint spinal-epidural anesthesia were categorized into two groups: Group A received 20ml of 0.5% ropivacaine and 10ml of normal saline injected into each side; Group B received 20ml of 0.5% ropivacaine, 1ml of nalbuphine, and 9ml of normal saline injected into each side. Serum prolactin (PRL) and cortisol levels were recorded before the operation (T0), and 2 (T1) and 24 (T4) hours after anesthesia. The time when colostrum was expressed was also recorded. The visual analogue scale (VAS) and Ramsay sedation scores were recorded at 2 (T1), 6 (T2), 12 (T3), and 24 hours (T4) after surgery. The incidence of postoperative nausea, vomiting, respiratory depression, itching, bradycardia, colostrum, and analgesic pump use were recorded. Results. Relative to group B, the prolactin levels pre-surgery (T0) showed no notable variance ( P > 0.05), although the prolactin levels at 2 (T1) and 24 hours (T4) post-surgery were considerably greater in group B than in group A ( P < 0.05). Colostrum production occurred sooner in group B than in group A ( P < 0.05). Prior to surgery (T0), the cortisol levels in group A and group B showed no notable variance ( P > 0.05); however, the cortisol concentrations in group A at 2 (T1) and 24 hours (T4) post-surgery were considerably greater than those in group B ( P < 0.05). Differences were found in the frequency of negative reactions between the two groups ( P > 0.05). In group B, the VAS pain levels were significantly lower than those in group A at T1–T4 ( P < 0.05). No notable variance was observed in the Ramsay sedation scores between the two groups at T1-T4 ( P > 0.05). Moreover, group B used an analgesic pump less frequently than group A ( P < 0.05). Conclusion. Nalbuphine combined with ropivacaine in transversus abdominis plane block may enhance maternal serum prolactin secretion, facilitating early lactation; It may also reduce serum cortisol levels, alleviating postoperative stress responses in cesarean section patients. Trial registration The trial was registered on November 04, 2025 at http://www.chictr.org.cn.(Clinical trial number：ChiCTR2500111707). Retrospectively registered.