Intra-uterine contraceptive device
Devices
Generally made of plastic containing Barium Oxide so as to be radiographically visible. The original device after the historical date stone used to prevent pregnancy in camels on trading trips, was the Lippes Loop. This was serpentine and rather large by modern standards, relying for its effect on size, and containing no copper. Because of this it had no real expiry date, and can be difficult enough to remove that owners may prefer to avoid this. “Loop” thus entered the vernacular for an IUCD, and like some of the Lippes Loops, is still with us. Assorted other shapes including the troublesome Dalkon Shield were tried. Later a smaller T shape became the type-object. The upright of this is wound with copper (on a Silver core), or in a later and more protean variant, has a collar which releases medroxyprogesterone.
A design intended to deal with the main limitation of IUCDs by taking up the minimum space in a small cavity consists merely of copper beads on a nylon thread, which is secured by punching the knot on the distal end into the uterine fundal myometrium.
All the copper and hormonal devices have a limited duration of action and, while this can be extended by careful design, they degrade gradually rather than instantly on schedule, and the remaining plastic frame is a respectably effective IUCD in its own right (bar the minimalist device), they require replacement at 5 to 8 years.
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Each device trails a couple of strands of fishing line, which are trimmed on insertion to a compromise between reassuring the lady the device is (still) there, and being obtrusive. Occasionally an end will be short and sharply beveled and cause dyspareunia (pain on sexual intercourse, often talked about in relation to women but can affect men as well).
Efficacy
Very good.
Placement
These devices are more effective in the uterine cavity than in the peritoneal cavity, best place them in the former and if necessary use or arrange ultrasound to exclude their presence in the latter.
Other Complications
Infection is more common with an IUCD in place than without, all other things being equal. There is some logic to regarding the threads as having a potential to encourage this, but their usefulness in removal – avoiding instrumentation of the uterus which might itself introduce infection, and as demonstration of continuing presence currently trumps this.
Ectopic pregnancy If a woman gets pregnant with an IUCD in place the likelihood of it being ectopic is considerably higher than usual. An early ultrasound should follow a high index of suspicion and willingness to refer in the event of pain or bleeding.
Hormonal effects of Mirena (medroxyprogesterone). Anecdotally, PMT-like feelings for a few weeks after insertion are common. In a very small minority sex-drive is reduced. These are presumably due to an initially higher release and absorption of the Progestogen, and should be more common in small women.
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