Acupressure seems to reduce pain during the active phase of labour in women having their first baby and it may be most effective during the initial phase of labour.
For further details:
Hjelmstedt, A., Shenoy, S. T., Stener-Victorin, E., Lekander, M., Bhat, M., Balakumaran, L., & Waldenström, U. (2010). Acupressure to reduce labor pain: a randomized controlled trial. Acta obstetricia et gynecologica Scandinavica, 89(11), 1453-1459.