Impact of different sufentanil concentrations in epidural labor analgesia on maternal and neonatal outcomes: a propensity score-matched cohort study.

PURPOSE: The optimal sufentanil concentration for patient-controlled epidural analgesia (PCEA) during labor remains uncertain. This study evaluated the association between sufentanil concentration strategies and maternal-neonatal outcomes.

METHODS

This single-center retrospective cohort study included parturients receiving sufentanil-containing epidural labor analgesia. Patients were stratified by fixed sufentanil concentration in the PCEA formulation. The observed concentration range was 0.25-0.50 µg/mL, and the median value of 0.30 µg/mL defined the Low-concentration group (≤ 0.30 µg/mL) and High-concentration group (> 0.30 µg/mL). One-to-one propensity score matching (PSM) was used to balance baseline confounders. The single primary endpoint was a composite safety outcome defined as any analgesia-related adverse event, including nausea and vomiting, pruritus, or lower limb motor blockade. Secondary outcomes included Visual Analog Scale (VAS) pain scores, breakthrough pain, PCEA bolus use, maternal satisfaction, labor outcomes, and neonatal metrics.

RESULTS

A total of 314 matched patients were analyzed. Both groups showed similar end-stage VAS scores and maternal satisfaction (P = 0.412), although the Low-concentration group required more PCEA boluses (median: 5 vs. 3; P = 0.004). The High-concentration group had more opioid-related maternal adverse events, including pruritus (31.8% vs. 14.6%; P < 0.001), nausea and vomiting, and minor motor blockade. High-concentration sufentanil was associated with higher odds of prolonged second stage of labor (adjusted odds ratio = 1.85; 95% confidence interval: 1.08-3.16).

CONCLUSIONS

Low-concentration sufentanil was associated with broadly comparable analgesic effectiveness and fewer opioid-related maternal adverse events. The second-stage difference was statistically significant but clinically modest and did not translate into significant differences in delivery mode, postpartum hemorrhage, or neonatal outcomes. These findings should be interpreted as hypothesis-generating real-world evidence.