Electric massage chairs reduce labor pain in nulliparous patients: a randomized crossover trial

Abstract

BACKGROUND: Labor pain varies significantly among pregnant women, ranging from mild to extremely distressing. Non-pharmacologic pain relief methods during vaginal birth are increasingly popular, either as a complement to pharmacologic agents or at times as the primary method of pain relief. Multiple trials have reported that manual or by-hand massage reduces labor pain. The effectiveness of full-body mechanical massage using electric massage chairs on labor pain remains unexplored.OBJECTIVE: To evaluate mechanical massage using electric massage chair on labor pain in nulliparous women.STUDY DESIGN: A randomized counterbalanced crossover trial was conducted in a university hospital in Malaysia from August 2022 to February 2023. Eligible nulliparas in labor with a minimum labor pain score of 5 (0-10 numerical rating scale) were enrolled. Participants were randomized to 30 minutes on the massage chair with mechanical massage followed by 30 minutes on the massage chair without mechanical massage, or the other way around in massage sequence. The primary outcome was change in pain score comparing pain with and without mechanical massage as a paired comparison for the entire trial participants. Secondary outcomes were across arms analyses of maternal and neonatal outcomes. The paired t-test, t test, Mann- Whitney U test, Chi square test and Fisher exact test were used as appropriate for the data.RESULTS: 208 women were randomized; 104 to each intervention. Data was available from 204 participants (103 randomized to massage first and 101 to no massage first). The primary outcome of change in labor pain score (0-10 Numerical Rating Scale, NRS) after massage and no massage (all participants included after crossover, paired t-test analysis) was mean±standard deviation 4.51±2.3 vs 5.38±2.1 mean difference - 0.87 (95% CI -1.14 to -0.59), p<0.001, a significant reduction in pain score after electric chair mechanical massage compared to no massage. On the across randomized arms secondary analyses, labor pain score after their first massage chair session was 4.35±2.52 (randomized to massage first, received massage as initial intervention) vs 5.66±1.73 p<0.001 (randomized to no massage first, received no massage as initial intervention) mean difference -1.31 (95% CI -1.91 to -0.748), a significant reduction after mechanical massage. Other distal maternal outcomes (mode of delivery, labor analgesia, duration of labor and maternal agreement that mechanical massage is effective for labor pain) and neonatal outcomes (Apgar score at 1 and 5 minutes, cord artery blood pH and base excess, and neonatal admission) were not different across randomized arms.CONCLUSION: Mechanical massage using an electric massage chair significantly reduces labor pain, offering a potential non-pharmacologic pain management option during labor.