A medical device and a method for providing a change of shape in a part of the body of an organism. The device is insertable into the body of the organism and comprises a member having a preferred state of shape and having a tendency to transfer its shape towards said preferred state of shape when being in a non-preferred state of shape. The device further comprises a resorbable means which is arranged to hold the member in the non-preferred state of shape and to delay the transfer when the device is inserted into the body of the organism by counteracting said transfer during resorption of the resorbable means by the surrounding body of the organism.