The performance of levonorgestrel rod and Norplant contraceptive implants: a 5 year randomized study

Abstract

A new contraceptive (LNG rod implants, Jadelle, Leiras Oy's registered trademark for rod implants) was prospectively evaluated in randomized 5 year comparison with Norplant (Population Council's registered trademark for contraceptive implants releasing levonorgestrel) capsule implants. The study involved 1198 women at seven centres. No pregnancies occurred in the first 4 years. At 5 years, the cumulative pregnancy rate was 1 per 100 users or less for each regimen. Annual discontinuation rates averaged 11-12 per 100 users (P > 0.05), corresponding to 5 year continuation rates of 55.1 for rods and 53.0 per 100 for capsules. Mean annual discontinuation rates for menstrual disturbances were 3.5 and 4.2 per 100 for rod and capsule implants respectively (P > 0.05), and mean annual removal rates for medical problems were 3.5 and 3.0 per 100 (P > 0.05) respectively. Apart from menstrual problems, headache, weight gain and acne were the principal medical reasons for removal. In proportional hazard analyses, family formation variables, age, parity and desire/non desire for another child, recorded at admission, significantly affected discontinuation rates for major decrement categories and for all reasons combined. Mean rod removal time was half that of Norplant (P < 0.01); complications of rod removal were at a lower rate. With these contraceptives indistinguishable in performance except for ease and speed of removal, LNG rod implants appear to be preferable to Norplant for use through 5 years by virtue of relative ease of removal.

PIP: This paper presents the 5-year randomized study on the performance of levonorgestrel rod (LNG) and Norplant contraceptive implants in 1198 women in 7 centers. In the first 4 years, no pregnancies occurred. At 5 years, the cumulative pregnancy rate was 1/100 users or less for each regimen. Annual discontinuation rates averaged 11-12/100 users, corresponding to a 5-year continuation rate of 55.1/100 for rods and 53.0/100 for capsules. Mean annual discontinuation rates for menstrual disturbances were 3.5/100 for rod and 4.2/100 for capsule implants. Reasons for discontinuation of use were vaginal spotting or bleeding, irregular bleeding, headache, weight gain and acne. Proportional hazard regression models established that family formation variables, age, parity, and desire for another child, recorded at admission, significantly affected discontinuation rates for major decrement categories and for all reasons combined. Mean rod removal time was half that of Norplant. Complications of rod removal were at a lower rate. This study concludes that there is an extremely high contraceptive effectiveness for LNG rod and Norplant implants; however, LNG rod implants were more preferable than Norplant for its relative ease in removal.