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[Unpublished] 1986 Jun 5. 3 p.By 1986 Norplant had undergone 10 years of clinical trials and had been used by more than 30,000 women in 25 countries. The contraceptive implant achieved effectiveness and continuation rates which equalled or exceeded all other forms of reversible contraception. The advantages of Norplant include the facts that it contains no estrogen, it is coitus-independent, it provides five years of protection in one simple procedure, and discontinuation is associated with a rapid return of fertility. The disadvantages are that a minor surgical procedure is required for insertion and removal and that menstrual patterns may be altered. The UN Population Fund issued the following guidelines to insure that clinical trials and introduction of Norplant proceed in the best manner possible: 1) such projects should be undertaken only with the full consent of the government involved as indicated in a formal agreement; 2) projects should be carried out in association with an executing agency such as the Population Council, one of the Population Council's Norplant introduction subcontractors, or the World Health Organization; 3) the executing agency will implement all inputs and activities involved in the clinical trials and/or introduction; 4) projects should be accompanied by widespread dissemination of full and accurate information about the method; and 5) projects should be accompanied by user attitude surveys.
In: Issues in reproductive technology I: an anthology, edited by Helen Bequaert Holmes. New York, New York, Garland Publishing, 1992. 11-30. (Garland Reference Library of Social Science Vol. 729)The progestin, levonorgestrel, suppresses ovulation and thickens the cervical mucus. The 1-year pregnancy rate is 0.2/100 users and the 5-year rate is 3.9/100 users. Contraindications of Norplant include abnormal bleeding, cardiovascular conditions, liver tumors, and breast cancer. The most frequent side effect is changes in bleeding patterns. A main concern of women's health advocates is that women are dependent on the medical establishment for insertion and removal of Norplant which affects the provider-client relationship. Family planning programs that do not recognize a woman's right to free choice of existing contraceptives and her right to have Norplant removed at any time may abuse Norplant. Health workers still do not know the long term effects of Norplant and Norplant's effect on the fetus in case of method failure or insertion while pregnant. Most acceptability studies occurred at university-based health clinics or at clinics in urban areas. The clinic environment may affect women's answers. These studies should occur in the community and home of users and nonusers. Another bias of these studies was clinic staff chose women who would tend to continue using Norplant. Thus subjects were not representative of the population. Researchers did not attempt to understand the women's perception of reproduction physiology and mode of action, the women's cost benefit analysis used to determine what method to use, or the consequences of menstruation changes. They also did not report on the information women received about contraceptive choices. The issue of abuse has arisen in Kansas where a state legislator proposed paying any mother on welfare US$500 if she uses Norplant. In California, a judge ordered a woman convicted of child abuse to use Norplant after release from jail and throughout her probation period.
Effective interception with the levonorgestrel-20-IUD contrarily to WHO advocated Lng-2-microdose IUD [letter]
CONTRACEPTION. 1988 Jun; 37(6):643.The World Health Organization's Special Program of Research, Development, and Research Training in Human Reproduction has investigated microdose administration of levonorgestrel to the uterine cavity and concluded that this approach is not safe or effective. In contrast to the excellent results obtained with 20 mcg of levonorgestrel release per 24 hours, the results of application of only 2 mcg release per 24 hours have been disappointing. There was a 6.7 increased relative risk of ectopic pregnancy with the levonorgestrel 2 IUD compared with the copper IUD, making this an unacceptable form of fertility control. On the other hand, the 12-month pregnancy rate for the levonorgestrel 20 IUD is 0.1/100 woman and the 12-month continuation rate is 80%. Removal rates for menstrual problems with this IUD are only 7.5%, and blood hemoglobin concentrations actually increase among users of the levonorgestrel 20 model.
Steroids. 1983 Mar; 41(3):243-53.The great demand for improved longacting injectabe steroid contraceptives, particularly in developing countries, and the relative lack of interest from the pharmaceutical industry to develop such products stimulated the World Health Organization to launch a synthetic and screening program to find improved, safe, and acceptable injectable preparations. More than 210 esters of norethisterone (17alpha-ethynyl-17beta-hydroxyestr-4-en-3-one) and levonorgestrel (D-(-)-13beta-ethyl-17alpha-ethynyl-17beta-hydroxygon-4-en-3-one) have been prepared in university-based research laboratories situated mainly in developing countries, and then screened by NICHHD in animal models. The following 3 compounds levonorgestrel butanoate, cyclopropylcarboxylate, and cyclobutylcarboxylate, proved to be particularly longacting when administered as microcrystalline suspensions. The overall strategy of this research and development program is described. (author's modified)
In: Goldsmith A, Toppozada M, ed. Long-acting contraception. Chicago, Illinois, Northwestern University, Program for Applied Research in Fertility Regulation [PARFR], 1983. 137-46.The characteristics and clinical performance of subcutaneously and vaginally implanted vaginal rings, under development for the past 15 years, are reviewed. This development has been restricted to public sector agencies, including the World Health Organization (WHO) and the Population Council, reflecting the lack of interest of the pharmaceutical industry in this area. Currently, only 1 progestogen-only releasing device is under development. The ring, which releases 20 mcg/day of levonorgestrel, produces plasma concentrations averaging 0.528 pmoles/ml, with a 20% decline in these concentrations 90 days after insertion. Ovulation was not inhibited in 90% of subjects studied in clinical trials, although inhibition of sperm transport in cervical mucus was noted in 85%. A WHO-sponsored Phase I trial of vaginal rings releasing progesterone, norethisterone, and levonorgesterel resulted in abandonment of development of the 1st 2 steroids. No pregnancies were noted in 360 woman-months of use of levonorgestrel-releasing rings. Phase II studies with these rings produced encouraging results, and results of Phase III multicenter clinical evaluations should be available by late 1983. In an attempt to improve bleeding performance, rings capable f releasing both an estrogen and a progestogen have been develeped under the auspices of the Population Council. 2 progestational agents--progesterone and levonorgestrel--coupled with estradiol have been used in these studies. Results with the levonorgestrel-estradiol ring have been most promising. A clinical trial involving 1147 users compared the pregnancy rate obtained with 2 such rings, 1 with a 58 mm outer diameter and 1 with a 50 mm diameter, to that with a low lose oral contraceptive (OC) containing 150 mcg levonorgestrel and 30 mcg ethynilestradiol. The 58 mm diameter ring produced only 5 pregnancies in 1 year of of use, compared with 9 pregnancies with the 50 mm ring and 10 pregnancies with the OC. Tests in both urban and rural areas of 2 Latin American countries found that 3-12.5% of total acceptors accepted the rings, with higher percentages in the rural areas. Acceptability fell after 6 months of use and recovered in the 2nd year. Since both the ovulation inhibiting discontinuous use ring and the low dose continuous use device are at the Phase III level, this new form of contraception may be available within the next few years.