The effect of labour and epidural analgesia on pain threshold

Summary Pain thresholds were measured using forehead pressure in 30 women before amniotomy and then during labour up to the point of their requesting analgesia. Measurements continued subsequently only in those having epidural analgesia alone. No significant change in pain threshold was seen in any patient up to the administration of analgesia, nor thereafter in the ten patients having epidurals. This study fails to confirm previous reports in animals of significant rises in pain threshold during parturition. It calls into question the view that previously reported changes in plasma endorphin levels may be associated with altered pain thresholds.