Gao J, Shen H, Zheng S, Fan H M, Wu M H, Han L H, Yao G Z
Contraception. 1986 May;33(5):443-54. doi: 10.1016/s0010-7824(86)80003-8.
A randomized comparative clinical study of the Steel Ring, VCu200 and TCu220c IUDs was carried out in Beijing. Six-hundred subjects were recruited and each group of 200 was inserted with one of the three devices. The TCu220c and the VCu200 had statistically significantly lower pregnancy and expulsion rates at one and two years of use than the Steel Ring. However, the Steel Ring consistently had the lowest rate of removal for pain and/or bleeding. At two years, the early differences of use-related discontinuation and continuation between the higher rates of the Steel Ring and the lower rates of the VCu200 and TCu220c were significantly reduced. There were no statistically significant differences of net event rates between VCu200 and TCu220c.
在北京进行了一项关于钢环、VCu200 和 TCu220c 宫内节育器（IUD）的随机对照临床研究。招募了 600 名受试者，每组 200 人，分别植入这三种器械中的一种。在使用 1 年和 2 年时，TCu220c 和 VCu200 的妊娠率和脱落率在统计学上显著低于钢环。然而，钢环因疼痛和/或出血而取出的比率始终最低。在 2 年时，钢环较高的使用相关停用率与 VCu200 和 TCu220c 较低的停用率之间在使用相关停药和继续使用方面的早期差异显著减小。VCu200 和 TCu220c 之间的净事件率在统计学上无显著差异。
