A system of controlling the discomfort level experienced by a subject in labour, the system comprising: a receiver configured to receive a signal from the subject to initiate comfort relief ; at least one monitor configured to determined vital sign data of the subject ; a determining circuit configured to determine whether the vital sign data fulfils a predetermined criterion ; at least one infusion device configured to infuse a comfort relief drug into the subject; and a control unit configured to control the at least one infusion device to infuse the comfort relief drug into the subject, based on whether the vital sign data fulfils a predetermined criterion , characterized in that the control unit is configured to control the at least one infusion device to infuse the comfort relief drug of a first loading into the subject if the subject sends a first signal to the receiver to initiate the comfort relief, wherein the control unit is adapted to control the at least one infusion device to infuse the comfort relief drug of a second loading into the subject if the subject sends a second signal to the receiver to initiate the comfort relief after having been infused with the first loading within a pre-determined period, wherein the control unit is adapted to control the at least one infusion device to infuse the comfort relief drug of a third loading into the subject if the subject sends a third signal to the receiver to initiate the comfort relief after having been infused with the second loading within a pre-determined period, wherein the third loading comprises a loading higher than the second loading and the second loading comprises a loading higher than the first loading; wherein each of the one or a plurality of infusion devices is controlled to infuse the comfort relief drug of a limit loading at a continuous infusion rate into the subject if (i) the subject sends a further signal to initiate the comfort relief or (ii) if on expiry of the pre-determined period if no further signal is sent. a receiver configured to receive a signal from the subject to initiate comfort relief ; at least one monitor configured to determined vital sign data of the subject ; a determining circuit configured to determine whether the vital sign data fulfils a predetermined criterion ; at least one infusion device configured to infuse a comfort relief drug into the subject; and a control unit configured to control the at least one infusion device to infuse the comfort relief drug into the subject, based on whether the vital sign data fulfils a predetermined criterion , characterized in that the control unit is configured to control the at least one infusion device to infuse the comfort relief drug of a first loading into the subject if the subject sends a first signal to the receiver to initiate the comfort relief, wherein the control unit is adapted to control the at least one infusion device to infuse the comfort relief drug of a second loading into the subject if the subject sends a second signal to the receiver to initiate the comfort relief after having been infused with the first loading within a pre-determined period, wherein the control unit is adapted to control the at least one infusion device to infuse the comfort relief drug of a third loading into the subject if the subject sends a third signal to the receiver to initiate the comfort relief after having been infused with the second loading within a pre-determined period, wherein the third loading comprises a loading higher than the second loading and the second loading comprises a loading higher than the first loading; wherein each of the one or a plurality of infusion devices is controlled to infuse the comfort relief drug of a limit loading at a continuous infusion rate into the subject if (i) the subject sends a further signal to initiate the comfort relief or (ii) if on expiry of the pre-determined period if no further signal is sent. <EOS>