A device for occluding a cervix has an elongated conduit sized and shaped to extend from a proximal end outside the vagina to a distal end near the cervix. A loop sized to fit around an exocervix is provided at the distal end. The loop is sufficiently flexible to be tightened and loosened around the exocervix. The device can include a rod inside the conduit. The rod has a distal end and a proximal end, and the loop is joined to the distal end of the rod. Moving the rod longitudinally relative to the conduit tightens or loosens the loop. The ends of the loop can also extend out through the proximal end of the conduit. Pulling on the ends through the conduit tightens the loop.