The Norplant System, the only long-acting subdermal contraceptive implant currently available in the United States, is the topic of three papers in this issue of The Journal of Family Practice. These papers are particularly timely and relevant in light of growing concern over unplanned and teenage pregnancy, as well as media attention directed at the Norplant System itself.
In the United States, 56.5% of the 6.3 million pregnancies that occurred during 1987 in women aged 15 to 44 were unplanned.[1] The United States also has the dubious distinction of leading five other developed nations in the number of unintentional pregnancies among its teenagers,[2-4] despite the similarity in rate of teenage sexual activity among industrialized countries.[3] Only 40% of US teenagers are reported to use contraception during the first year of sexual activity.[1,5] Since the late 1970s, one in eight women aged 15 to 19 have become pregnant each year.[6,7]
At the same time, data suggest that it is possible to improve these statistics by introducing new contraceptive methods and continuing to encourage appropriate use of existing methods, supported by intensive patient counseling.[8-10] It follows, therefore, that correct contraception education must be incorporated into an individual's lifestyle as early as possible. If this could be accomplished before adolescence, then perhaps these good contraceptive habits would have a positive impact on the unacceptably high unintentional pregnancy rate in both adults and teenagers.
Teaching couples about the appropriate use of contraceptives does little good without the availability of several contraceptive choices to meet a range of lifestyle needs. The paucity of options in the mid-1980s was capped of when the Cu-7 (G. D. Searle, Chicago, Ill), a copper intrauterine device (IUD), was withdrawn from the market without a new method on the horizon to replace it.[11] The copper IUD, which had been used extensively and successfully by several industrialized nations to reduce unintended pregnancy, did not become an option again until ParaGard, an intrauterine copper contraceptive now approved for 10 years of use, became available for the US market in 1990. As a result of the limited availability of long-term contraceptive options for so many years, however, surgical sterilization increasingly became the primary contraceptive choice of US couples.
The need for reversible, effective contraception for all couples led to the development of several new options in the 1990s. Because 66% of sexually active US couples wish to defer childbearing temporarily, the 5-year levonorgestrel implant (Norplant System), the 3-month injectable (Depo-Provera), two new progestins (norgestimate and desogestrel) in oral contraception, and new condoms (including the polyurethane female condom) have been welcome additions to the array of contraceptive options, allowing the best fit between patient needs and contraceptive efficacy.[1]
When the Norplant System came on the market in 1991, it was the first new contraceptive system approved for use in the United States in 30 years. It is also the most extensively tested contraceptive implant, with nearly 60,000 women participating in clinical trials to date.[12] Today, the Norplant System is used by nearly 1 million US women and 2.5 million women worldwide (1995 data on file at Wyeth-Ayerst Laboratories, Philadelphia, Pa).
Norplant consists of six subdermal Silastic capsules that are placed in the inner aspect of the upper nondominant arm in a minor surgical procedure, requiring a local anesthetic. Removal of the Norplant System, which can take place at any time up to 5 years after insertion, also requires local anesthesia but a slightly longer incision.[13] Its 5 -year efficacy approaches that of surgical sterilization, yet it is completely reversible.14 This high efficacy can be attributed to the long-term release of low blood levels of the progestin levonorgestrel, which inhibits ovulation and thickens cervical mucus, blocking sperm penetration. The method is not coitally dependent, which also contributes to its efficacy rate, as poor user compliance is an important reason why other contraceptive methods may frequently fail.
International Experience
One 5-year study of Norplant use in 10,718 Chinese women is particularly instructive in understanding the risks and benefits of Norplant use.[15] The 5-year average annual pregnancy rate was 0.3 per 100 women, with an ectopic pregnancy rate of 0.09 per 1000 women. Five-year continuation rates were extremely high: 72 per 100 original acceptors. Bleeding disturbances were by far the most common reason leading to discontinuation during the 5 years (20 per 100 women). This bleeding usually took the form of continuous spotting, rather than hemorrhage, as most patients experienced hemoglobin increases with time. These bleeding episodes result from the acyclic endometrial shedding typical of all progestin-only methods. Approximately 10% of US users request removal of the capsules because of irregular bleeding.[13,16] Medical reasons for terminations (excluding pregnancy) in the Chinese study, which occurred at a rate of 5.7 per 100 users, included headache, dizziness, and weight gain, all of which are common side effects of all hormonal methods.
US Experience
Although the international experience of Norplant System users has been extensively looked at[17] and is similar to that of the Chinese investigators, it is possible that the efficacy findings may not be directly applicable to US women, as constitutional factors, such as weight, may differ.[18-24] In addition, findings of high continuation rates despite high reported rates of prolonged nuisance bleeding do not necessarily reflect acceptance by the patient. Some patients, for example, may find it difficult to have their implant removed, often because of limited access to those with the skill to remove it.[25]
One of the first US studies to examine acceptability rates was published by Darney et al[25]in 1990. Their findings characterized the 5-year experience of 205 Norplant users attending an urban family planning clinic in San Francisco. The majority (70%) of these women were using the two-rod system (Norplant-2), which is not yet commercially available. In general, they were multiparous and married, with a wide range of ethnicity, education, and family income. Many women chose to enroll in this clinical trial because of dissatisfaction with other available methods of contraception (89% were using contraception) and because they planned to have children in the future.
Of the women participating in the trial, 95% experienced at least one side effect. Over 80% experienced menstrual changes, 32% weight changes, 24% headaches, 16% mood changes, and 15% acne. Nevertheless, because of dissatisfaction with previous methods, the majority of women were willing to tolerate these side effects, as evidenced by a 53% 5-year continuation rate. Interestingly, 61% of women who discontinued Norplant said they would use this method again. The authors concluded that Norplant appeared to be a highly acceptable method of contraception, despite the frequent occurrence of bothersome side effects in a group of fairly diversified women in an urban setting. Despite frequent side effects, experiences of high acceptability are similar among many different groups of women, including adolescents,[26,27] inhabitants of scattered inner city areas within Dallas,[28] Houston,[29] and Baltimore,,311 and finally, within a predominantly middle-class private practice setting.[31] All programs can attribute their apparent success to the tendency of Norplant users to be a highly self-selected, intensely counseled group of women who desire long-term, reversible contraception.
Current Issues
Although most Norplant users appear highly satisfied with their method, recent media coverage of the method has been less than flattering because of class-action lawsuits filed in Texas, Illinois, and Florida against the manufacturer, Wyeth-Ayerst Laboratories in Philadelphia.[32-35] The number of newspaper solicitations by lawyers willing to file claims on behalf of plaintiffs also is rising.[36] Because the majority of suits are based on claims of postinsertional pain, prolonged or difficult removals, and inadequate warning of potential side effects, an examination seems in order. Moreover, clinicians should be aware that publicity surrounding this litigation may increase apprehension among current users and lead some women who are considering using Norplant to select other, perhaps less effective or less appropriate methods of contraception.
