An apparatus for controlling a flow of sperms in a uterine tube formed by a uterinetube wall of a patient's uterine tube comprises an implantable constrictiondevice for gently constricting (ie. without substantially hampering the bloodcirculation in the uterine tube wall) at least one portion of the uterine tubewall to influence the flow in the uterine tube, and a stimulation device for stimulatingthe wall portion of the uterine tube wall. A control device controls the stimulationdevice to stimulate the wall portion, as the constriction device constrictsthe wall portion, to cause contraction of the wall portion constricted by theconstriction device to further influence the flow in the uterine tube. The apparatuscan be used for restricting or stopping the flow in the uterine tube, or for activelymoving the fluid in the uterine tube, with a low risk of injuring the uterine tube.
