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Updated: Sep 10, 2026
Comprehensive Evaluation of the Effectiveness and Safety of Placenta-Targeted Drug Delivery Using Three Complementary Methods
Published on: September 10, 2018
A 5-year evaluation of NORPLANT contraceptive implants in China
Objective:
To assess the efficacy, safety, and acceptability of NORPLANT implants when used by Chinese women.
Methods:
In a prospective, multicenter clinical trial, 10,718 women selecting NORPLANT implants were monitored semiannually for the first 2 study years and then annually through 5 years. Life table rates of pregnancy and other terminations were calculated, as were incidence rates of serious conditions leading to termination.
Results:
The 5-year average annual pregnancy rate was 0.3 per 100 and the ectopic pregnancy rate was minimal, 0.09 per 1000 woman-years. Pregnancy rates correlated significantly with weight, but regardless of weight group, annual average pregnancy rates were less than one per 100. Younger women experienced higher pregnancy rates than did older users. Headache, myoma, dizziness, and weight gain led more frequently to termination than did other adverse events apart from menstrual disturbances. Mortality during use was 2.0 per 10,000 years, based on 44,954 years of experience. There were no cardiovascular or cerebrovascular deaths, and no deaths were attributable to NORPLANT use. Seventy-two per 100 initial acceptors used the implants continuously for 5 years.
Conclusion:
NORPLANT implants proved highly effective, safe, and acceptable among Chinese women regardless of province, age, or weight at admission.
