The invention relates to a system for performing in vivo pressure measurements, comprising one or more pressure sensors (14), a connector module (20) provided with one or more electrical coupling elements for the one or more pressure sensors and one or more coupling means (10) for a catheter. The one or more coupling means for a catheter are each provided with at least three ports and a tap for coupling two of the three ports as desired. According to the invention each of the one or more coupling means is embodied as a coupling module which is releasably connectable to the connector module, and the pressure sensors (14) are arranged on the coupling modules (10).The invention also relates to a coupling module (10) for a catheter as described as component of the system (1) according to the invention.