%0 Journal Article
%T IMAP statement on Norplant subdermal contraceptive implant system.
%A  
%J IPPF Med Bull
%V 27
%N 2
%D Apr 1993
%M 12345306
暂无%X The Norplant implant system consists of 6 silastic capsules which deliver levonorgestrel to protect against pregnancy over 5 years. Clinical trials were conducted in 46 countries.  The 5-year cumulative pregnancy rate is 3.9%.  Norplant's efficacy falls as weight increases. Its failure rate is lower than that of combined oral contraceptives and most IUDs.  Counseling is linked to acceptability.  Medical personnel should be trained in counseling potential Norplant acceptors.  They must undergo formal training in insertion and removal of Norplant.  The first year and fifth year continuation rates are 75-90% and 25-78%, respectively.  Bleeding irregularities are the main reason for discontinuation and the most commonly reported side effects. Levonorgestrel changes the cervical mucus and suppresses ovulation and the endometrium.  Toxicological and teratological data on levonorgestrel and silastic show that Norplant is safe.  It appears that Norplant does not cause any major pathological changes in the endometrium, liver, kidney, and adrenal and thyroid glands.  Levonorgestrel in Norplant is linked to a slight increase in serum glucose levels which are not of significant consequence.  Its effects on lipids and lipoproteins are not clear.  Fertility returns to Norplant users shortly after removal.  The return to fertility pattern basically matches that of other methods. Contraindications of Norplant use are confirmed or suspected pregnancy, previous ectopic pregnancy, breast cancer, cancer of the genital tract, cerebrovascular or coronary artery disease, acute liver disease, and undiagnosed abnormal genital bleeding.  Norplant should be inserted subdermally in the upper arm during the first 7 days after menstruation begins.  The capsules must be removed after 5 years if pregnancy is to be avoided.  Before family planning programs provide Norplant, managers should make sure the staff is adequately prepared.  Health personnel, counselors, potential users, and the public need informational materials on Norplant.