RCT Challenges Role of Thermotherapy in Early Perineal Pain Management
Can a warm compress or cold pack really make a difference for new mothers experiencing perineal pain after vaginal birth? While non-pharmaceutical pain relief is attractive for both patients and clinicians, new evidence challenges the effectiveness of these widely used therapies.
Study Design: The First Factorial RCT on Thermotherapy
A French multicenter, open-label, 2×2 factorial randomized controlled trial enrolled 105 women (out of 115 screened) to evaluate the effect of heat therapy (warm compresses) during pushing and cooling therapy (cold packs) immediately postpartum. The primary endpoint was mean self-reported perineal pain on a 0–10 scale during the first 24 hours after delivery. Secondary outcomes included perineal healing, perineal injuries, need for additional analgesia, and maternal birth experience.
Results: No Significant Impact on Perineal Pain
Pain Scores: Neither warm compresses nor cold packs provided a statistically significant reduction in mean perineal pain at 24 hours compared to standard care (HT vs. SC: 4.0 ± 2.5 vs. 3.6 ± 2.2; CT vs. SC: 4.3 ± 2.5 vs. 3.4 ± 2.2).
Additional Outcomes: There were no significant differences in the rates of perineal tears, episiotomy, perineal healing, or use of additional pain medication between intervention and control groups.
Maternal Experience: Nearly half of the women perceived a moderate reduction in pain and most would opt to use these interventions again. Midwives reported high feasibility and satisfaction with protocol adherence.
Why These Findings Matter for Clinical Practice
While thermotherapy was safe, easy to implement, and well accepted, it did not deliver a clinically meaningful reduction in early postpartum perineal pain.
Maximal pain at day 1 was actually higher in the cold pack group, though this may be due to baseline imbalances and caution is warranted in interpretation.
The study highlights the need for better targeting—future research may need to focus on women at higher risk of severe pain or those with significant perineal trauma.
Limitations and Future Directions
The trial stopped at 50% of its planned sample size due to slow recruitment, potentially underpowering detection of smaller or subgroup-specific effects.
Interventions were tested at moderate temperatures to ensure safety, which may differ from prior studies using higher heat.
The open-label design may introduce some performance bias, but the pain measures remained consistent across groups.
Conclusion
Despite their popularity and patient acceptance, warm compresses and cold packs did not prevent or reduce perineal pain in the first 24 hours after vaginal birth in this pilot RCT. Non-pharmaceutical pain relief remains a priority, but future studies should refine target populations and intervention protocols to maximize benefit.
Key Points
Thermotherapy (warm compresses or cold packs) did not reduce early postpartum perineal pain compared to standard care.
No significant differences in perineal healing, injury rates, or need for additional analgesia were found.
Interventions were highly accepted and feasible for both women and midwives.
Study was underpowered due to early termination.
Future research should target high-risk groups and explore optimal timing and temperature settings.
Citation:
Blanc-Petitjean P, Rollet C, Meunier G, Mandelbrot L, Le Ray C, Chantry AA. Thermotherapy for prevention of perineal pain after vaginal birth: Evaluation of warm compresses and cold packs using a factorial randomized controlled trial. Int J Gynecol Obstet. 2026;00:1-10. doi:10.1002/ijgo.71243
