Intra-uterine contraception with a new antigon model, and investigation of the mechanism of action of intra-uterine devices
Lebech, P.E.; Andersen, E.S.; Berggreen, K.; Neumann, E.
Danish Medical Bulletin 18(6): 146-151
1971
ISSN/ISBN: 0907-8916 PMID: 5136193 Document Number: 37641
Based on a review of the literature, it was hypothesized that an IUD's effect is local and increases with the size of the area covered by the IUD. This hypothesis was tested by comparing clinical material on the plain Antigon IUD with the newly designed Antigon winged model; the newer design increases the contact area by 50%. Data for 1151 patients over 18,599 woman-months of observation were collected from 2 hospitals in Denmark and 1 in Sweden. Average age ranged from 27.1-29.2 years, with average parity ranging from 2.2-2.9. There were 6.8% pregnancies and expulsions, 10.1% removals, and an 80.3% acceptability rate. Because the pregnancy rate has been halved with the Antigon winged model, it is thought that an IUD effects the local obstruction of blastocyst nidation.