Intrauterine device with retrieval thread

1. An intrauterine contraceptive system, comprising:

an inserter; and

an intrauterine device, configured to change from a delivery configuration to an expanded configuration when released from constraint within a uterus, the intrauterine device comprising:

a wire frame, comprising:

a distal end;

two arms extending laterally; and

a twist portion between the distal end and the two arms;

one or more substance delivery members coupled with the wire frame;

a retrieval thread permanently attached to the distal end of the wire frame for removing the intrauterine device from the uterus, wherein the retrieval thread has a length such that the retrieval thread does not require cutting after the intrauterine device is delivered into the uterus; and

a release thread releasably attached to the distal end of the wire frame, for coupling the intrauterine device with the insertion device, so that when the release thread is no longer needed for securing the intrauterine device to the insertion device, the release thread may be pulled off the intrauterine device.

2. A system as in claim 1 , wherein the length of the retrieval thread is between 5 centimeters and 9 centimeters.

3. A system as in claim 1 , wherein the retrieval thread is at least partially housed within the insertion device during insertion of the intrauterine device into the uterus.

4. A system as in claim 1 , wherein the one or more substance delivery members are selected from the group consisting of copper sleeves, copper wires, hormone delivery sleeves, drug delivery depots, drug coatings, and drug eluting carriers.

5. A system as in claim 1 , wherein the one or more delivery members are coupled with the wire frame near two ends of the two arms and near the distal end, below the twist portion.

6. A system as in claim 1 , wherein at least one of the retrieval thread or the release thread comprises:

a first portion having a first color; and

a second portion having a second color, wherein the first and second colors contrast with one another sufficiently to be visible during a physical examination of a patient in which the intrauterine device has been placed.

7. A system as in claim 6 , wherein the first portion extends from a point of attachment of the retrieval thread or the release thread with the intrauterine device to a location along the retrieval thread or the release thread between 2 centimeters and 3 centimeters from the point of attachment.

8. A system as in claim 6 , wherein at least one of the retrieval thread or the release thread further comprises a third portion having the first color, wherein the second portion comprises a band of the second color, with the first and third portions on either side of the band.

9. The system of claim 1 , wherein a substance carried and delivered by the one or more substance delivery members is selected from the group consisting of copper, Levonorgestrel, other hormones, and other spermicidal agents.

10. An intrauterine contraceptive device, comprising:

a frame configured to change from a delivery configuration to an expanded configuration when released from constraint within a uterus, the frame comprising:

a distal end;

two arms extending laterally; and

a twist portion between the distal end and the two arms;

one or more hormone delivery members coupled with the frame;

a retrieval thread permanently attached to the distal end of the frame for removing the intrauterine device from the uterus, wherein the retrieval thread has a length such that the retrieval thread does not require cutting after the intrauterine device is delivered into the uterus; and

a release thread releasably attached to the distal end of the frame, for coupling the intrauterine device with the insertion device, so that when the release thread is no longer needed for securing the intrauterine device to an insertion device, the release thread may be pulled off the intrauterine device.

11. A device as in claim 10 , wherein the length of the retrieval thread is between 5 centimeters and 9 centimeters.

12. A device as in claim 10 , wherein the one or more hormone delivery members deliver Levonorgestrel.

13. A device as in claim 10 , wherein the one or more hormone delivery members are selected from the group consisting of drug delivery depots, drug coatings, and drug eluting carriers.

14. A device as in claim 13 , wherein the one or more hormone delivery members comprise a drug eluting carrier containing, coated or impregnated with Levonorgestrel.

15. A device as in claim 14 , wherein the drug eluting carrier is disposed over the twist portion between the distal end and the two arms.

16. A device as in claim 10 , further comprising at least one copper member coupled with the frame, wherein the at least one copper member is selected from the group consisting of copper wires and copper sleeves.

17. A device as in claim 10 , wherein the frame comprises an elongate shape memory wire made of a material selected from the group consisting of Nitinol, spring stainless steel, other shape memory metal alloys, and shape memory polymers.

18. A device as in claim 17 , wherein a first end of a first arm of the two arms of the frame comprises a first loop, and wherein a second end of a second arm of the two arms comprises a second loop.

19. The device of claim 18 , further comprising:

a first sleeve fixedly attached to the first end of the elongate shape memory wire to form the first loop; and

a second sleeve fixedly attached to the second end of the elongate shape memory wire to form the second loop.