title: A new experimental three-dimensional, reticular intrauterine device (3-DRIUD) composed of nitinol and silicone rubber.
abstract: BACKGROUND
  The aim of this study was to explore a new three-dimensional, reticular intrauterine device (3-DRIUD) composed of nitinol and silicone rubber and to observe the contraceptive effect of the device in rats.
  
  
  METHODS
  Two contraceptive experiments were performed. In the first, female rats underwent bilateral placement of a 20.0-35.0-mm 3-DRUID (experimental group, n=30) via an abdominal incision or a sham operation with no IUD (control group, n=30). Two weeks after the operation was performed, the rats from either group were caged together with male rats. The contraceptive effects of the 3-DRIUD were observed at 1 to 3 months postoperation, after which the 3-DRIUDs were removed. One month after this second operation, the rats from the two groups were again coupled with fertile male rats. In a second experiment, female rats underwent bilateral placement of a 10.0-mm 3-DRUID (n=5) via an abdominal incision or a two-dimensional IUD (2-DIUD, n=20) and mated 1 month after surgery. The single-pipeline IUD was placed in 10 rats, while the enfolded-pipeline IUD was placed in 10 different rats.
  
  
  RESULTS
  In the first experiment, none of the females in the experimental 3-DRIUD group became pregnant (0/30, 0%) after 3 months, compared to 28/30 (93.3%, p<.0001) rats in the control group. After the 3-DRIUDs were removed from the experimental group after 3 months, 27/30 (90%) became pregnant, compared with 29/30 (97%, p>.05). The litter size (mean±SD) did not differ between groups (10.9±1.5 3-DRUID, 11.2±1.1 control, p>.05). In the second experiment, five rats had a 10.0-mm 3-DRUID (which was one third the length of one uterine horn) inserted into the bilateral uterine horns, and three of the five rats became pregnant. All 20 rats were pregnant 1 month after the insertion of the 2-DIUD. Thus, the contraceptive rate for the 2-DIUD group was 0.
  
  
  CONCLUSIONS
  The primary contraceptive mechanism effect of the new 3-DRIUD in rodents appears to be a result of occupying physical space in the uterus.
authors.affiliation: Key Laboratory for Technique for Improving Birth Outcome, Shandong Provincial Institute of Science and Technology for Family Planning, 69 Yuhan Road Jinan, Shandong province, 250002, China. qiuyi987@sina.com
authors.forename: Yi
authors.initials: Y
authors.lastname: Qiu
authors.forename: Lei-Guang
authors.initials: LG
authors.lastname: Wang
authors.forename: Mei-Hua
authors.initials: MH
authors.lastname: Zhang
authors.forename: Yan-Ping
authors.initials: YP
authors.lastname: Zhang
authors.forename: Ai-Dong
authors.initials: AD
authors.lastname: Zhang
authors.forename: Dan-Tong
authors.initials: DT
authors.lastname: Yang
mesh_terms: D000497:Alloys; D000818:Animals; D055598:Chemical Phenomena; D005260:Female; D007247:Infertility, Female / Q000517:prevention & control; D007433:Intrauterine Device Expulsion; D007434:Intrauterine Devices / Q000009:adverse effects; D008098:Litter Size; D008422:Materials Testing; D009532:Nickel; D011247:Pregnancy; D051381:Rats; D017208:Rats, Wistar; D012826:Silicone Elastomers; D014025:Titanium; D014595:Uterine Perforation / Q000517:prevention & control
chemical_list: D000497:Alloys; D012826:Silicone Elastomers; C013616:nitinol; D009532:Nickel; D014025:Titanium