"Bleeding pattern, outcome of accidental pregnancies and levonorgestrel plasma levels associated with method failure in Norplant implants users"

A cohort study of Norplant implant: Side-effects and acceptance

“…Nevertheless, the pregnancy rate of these two groups was also calculated by log-rank test and there is no statistical significant difference (p = 0.167). Previous researchers also found the pregnancy rate to be less than 1.0% by the fifth year of use [5,38,39].…”

“…This occurs in 0.0-0.5% of women in the first three months after insertion [36]. In the first five years of use, the chances of pregnancy are less than one per 100 women per year, and no pregnancies in year 1 [5,[37][38][39][40][41][42][43]. Amenorrhea is less common than prolonged bleeding or spotting.…”

Contraceptive Implantsa

“…The outcome of pregnancies occurring during Norplant use is similar to that of conceptions occurring in untreated women. 6 The rate of ectopic pregnancies was 0.28 per lo00 woman-years in 21,569 woman-years observed in ICCR studies, which is lower than the 1.5 rate observed in the United States in women aged 15-44 years5…”

Implant Contraception

“…In two studies, women with pregnancies were more likely to have regular bleeding patterns immediately prior to conception (P <0.05). 94,111 All implant users with amenorrhea after periods of regular bleeding should be evaluated for pregnancy.…”