Abstract: A device and method for intravaginal, barrier-type prevention of conception and infection by sexually-transmitted diseases based upon a barrier-type device including a flexible cervical dome having a continuous fornical rim defining an opening into the dome and a continuous, annular, vaginal brim which circumscribes and is attached to the cervical dome at the fornical rim. The vaginal brim is reverse-folded from the fornical rim, and has a dimension which continuously increases with circumferential symmetry from an anterior vaginal extension of the brim to a posterior vaginal extension of the brim which is diametrically opposite the anterior vaginal extension. The fornical rim is characterized in having a lip which extends inwardly from the opening toward the centerline of the dome. The brim has a curvature in a direction away from the dome.