A five-year study of NORPLANT II rod implants was undertaken in four large cities and metropolitan areas in eastern China. Designed to test the safety, efficacy and acceptability of these implants, the study involved 1,208 women and was conducted concurrently with a similar study of NORPLANT capsule implants. At the end of five years, the gross pregnancy rate was 0.65 per 100, and the continuation rate was 65.3 per 100. Both these values were similar to and not statistically different from the rates of the capsule implant users. In 4,828 woman-years of use, there were few severe adverse events reported. Users and providers found the method to be an acceptable long-term contraceptive method of great reliability.
PIP: Norplant implants gradually release levonorgestrel, thus conferring protection against pregnancy. The first generation implants are in capsule form and require the implantation of six separate units. The second generation of the implant system, Norplant II, has release rates similar to those of the six-capsule Norplant system, but requires the subdermal implantation of only two rods in the inner aspect of the upper arm. It may be easier to insert and remove two rods instead of six capsules. A five-year study of the safety, efficacy, and acceptability of Norplant II rod implants was therefore conducted in Beijing, Shanghai, Shenyang, and Tianjin. 1208 women were recruited to use the rods at four centers in the cities beginning December 1, 1984, to have their experiences compared against those of 2842 users of Norplant capsules at the same sites. Manufactured by Leiras Pharmaceutical of Turku, Finland, the implants used in the study measured 4.4 cm long and 2.4 mm in diameter and contained physical mixtures of levonorgestrel and a polydimethylsiloxane elastomer cured into rods covered with thin-walled silicone rubber tubing. A gross pregnancy rate of 0.65/100 resulted at the end of five years, with a continuation rate of 65.3/100. These rates are similar to and not statistically different from the rates among capsule implant users. Few severe adverse events were reported over the 4828 woman-years of use. Users and providers thus found the method to be an acceptable long-term contraceptive method of great reliability.