The "perfect contraceptive" population.
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Major complications attributable to oral contraceptives (OCs) may occur in the circulatory system. The inherent risk factors, such as race and family history, are unchangeable. Others may be altered by patient counseling and subsequent adjustment of certain behaviors. Hypercoagulability is estrogen dose related. Older, high-dose-estrogen OC users were at 40% increased risk of mortality from thromboembolic phenomena. Reduction in estrogen content has unmasked the androgenic effects of some synthetic progestogens. These effects may include progression of atherogenesis, effected through changes in cholesterol and lipoproteins; reduction in sex hormone binding globulin (SHBG), which enhances the androgenic effect; and changes in carbohydrate metabolism. This review of clinical findings is based on four studies; three had prospective cohort designs, and one was a prospective randomized comparison of a norgestimate-containing OC with a norgestrel-containing one. Numbers of subjects ranged from 20 to 59,701; the largest evaluated 343,348 cycles of treatment. Study intervals were from 4 to 24 months. The findings reported here are from the individual studies. 1. The normal value for cholesterol is less than 200 mg/dL. Of 2,197 women who met this cut-off point, 95% remained below it after 6 months of treatment. Of 756 who initially exceeded this value, 25% were below after 6 months and 75% remained above it. All studies to date have demonstrated that norgestimate produces consistent and significant elevations in high-density lipoprotein levels and variable change in low-density lipoproteins. A similar effect was noted on serum triglyceride values.(ABSTRACT TRUNCATED AT 250 WORDS)
A tampon applicator is described in which a spermicidal solution is stored in the plunger and released into a disposable tampon just prior to insertion of the tampon. The experiences of 26 volunteers who used the device at the time of coitus suggest that the method is both acceptable and feasible, although four of the ten subjects attempting tampon removal by themselves experienced some difficulty. Postcoital studies of the cervical mucus near the time of ovulation were conducted on 16 subjects and no motile spermatozoa were found. This suggests a high degree of theoretical effectiveness.
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The postpartum period is an ideal time to begin contraception, as women are more highly motivated to adopt contraception at this time and it is convenient for both patients and service providers. For intrauterine device (IUD) contraception, this period offers other advantages, such as ease of insertion and minimal adverse impacts on breastfeeding. Among early studies, most postpartum insertions were performed anywhere from a few hours to seven days or more after delivery, and retention of the IUD in the uterus was poor. Since the 1970s, immediate postplacental insertion (IPPI), i.e., IUD insertion performed within 10 minutes after placental delivery, has been advocated, and fairly, low expulsion rates have been reported. Up to now, IPPI has not been widely accepted in clinics because its expulsion rate still appears to be higher than that of interval insertion. In order to further study IPPI and perfect this contraceptive technique, it is essential to comprehensively review IPPI results and compare the Chinese experience with that of the rest of the world.
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This report provides an update of the authors' previous estimates of first-year probabilities of contraceptive failure for all methods of contraception. Estimates are provided of failure during typical use (which includes both incorrect and inconsistent use) and during perfect use (correct use at every act of intercourse). The difference between these two probabilities provides a measure of how forgiving of imperfect use each method is. These revisions are prompted by recent studies that provide the first estimates of failure during perfect use for periodic abstinence and the cervical cap, by more complete evaluations of implants, and by the appearance of the Copper T 380A and disappearance of other IUDs from the US market. Also provided is a more complete explanation of how the previous estimate of the probability of becoming pregnant while relying solely on chance should be interpreted, and this estimate is revised slightly downward.
Reanalysis of data on the ovulation method of natural family planning collected by the World Health Organization yields the following conclusions. The method is effective during perfect (correct and consistent) use, with a first-year probability of failure of 3.4%. However, it is extremely unforgiving of imperfect use, with a first-year probability of failure of 84.2% if the method is not used correctly. During the initial year, 87% of the cycles were characterized by perfect use. Nevertheless, the 13% of cycles characterized by imperfect use had a tremendous impact on the overall failure rate. During the first year of typical use 22.5% of the women in the clinical trial became accidentally pregnant.
The concept of transdermal delivery (TD) for steroid application has nowadays been largely accepted for hormone replacement therapy in the menopause. It is only recently that the same concept has been envisaged for contraception. The skin can be penetrated by both estrogens and progestins, provided they are delivered in an appropriate solvent. About 10% of the total dose applied topically is actually absorbed. The transdermal delivery systems (TDS) presently available are either of the reservoir type (membrane-moderated system) or of the matrix dispersion type where the drug is dispersed into a polymer matrix. Estradiol (E2) is the most appropriate steroid for TD and can be combined with progestins to ensure a contraceptive effect. Only potent progestins should be used to achieve effective plasma levels with low doses in order to maintain an acceptable small surface of TDS. TDS changed weekly and delivering both E2 and levonorgestrel (L-NG) at daily dosages of 38.4 (+/- 7.5) and 28.8 (+/- 7.2) micrograms/10 cm2 per day respectively, showed ovulation suppression. Another progestin derived from norprogesterone (ST 1435) has been shown to penetrate the skin when suspended in acetylated lanolin or dissolved in a hydroalcoholic gel and to ensure ovulation suppression at a dose of 2 mg per day in a small number of cycles. These preliminary data demonstrate the feasibility of suppressing ovulation in women by transdermal absorption of steroids. Using TDS for contraception implies that such systems should be perfectly adhesive, well tolerated locally and achieve nearly 100% efficacy. These targets are very challenging, however, the potential advantages are so high that the concept deserves further development.
The authors present a continuation of the thesis suggesting that the most rational procedure for regulating fertility is a perfectly safe, even though not completely effective, contraceptive method combined with safe methods for terminating pregnancy when the contraceptive fails. This analysis demonstrates that, compared with the risk of death from pregnancy and childbirth, major reversible methods of fertility control--the pill, IUDs, condoms, and diaphragms--and abortion are associated with very low levels of mortality. The exception to this statement is pill use after age 40 by women who smoke. This analysis also confirms the very low mortality associated with using the condom and diaphragm with early induced abortion as a backup to terminate pregnancies resulting from contraceptive failures.
Oral contraceptives are almost optimally effective but not yet perfectly safe. They can cause favourable or adverse unintended effects which cannot always be attributed to either the estrogen or the progestagen; however, in many instances a fair differentiation is possible. Type, intensity and frequency of side effects depend on dosage, duration of administration and on the structure of the substance. Some favourable side effects of estrogens are used for therapeutic purposes. Adverse side effects of estrogens are either subjectively disturbing only, or medically important, but few are life threatening. Dose dependence has been established, a structure relationship is unlikely.
Because the research design for the clinical trial establishing the contraceptive efficacy of the female condom--a six-month life-table probability of failure of 15% (12% in the United States vs. 22% in Latin America)--did not include randomization with another method of contraception, no definite conclusion about its comparative efficacy is possible. Comparisons using other female barrier methods as historical controls, however, provide evidence that, among women in the United States, the contraceptive efficacy of the female condom during typical use is not significantly different from that of the diaphragm, the sponge or the cervical cap. The six-month probability of failure during perfect use of the female condom is 2.6% among U.S. women, similar to rates for the diaphragm and the cervical cap but significantly lower than that for the sponge. Meaningful comparisons with the male condom are not possible because of the lack of data from carefully controlled prospective clinical trials. Extrapolations from the results on contraceptive efficacy suggest that perfect use of the female condom may reduce the annual risk of acquiring the human immunodeficiency virus by more than 90% among women who have intercourse twice weekly with an infected male.
Eight-seven cases of secondary amenorrhoea of more than 6 months' duration developing after treatment with oral contraceptives (group I) were compared with 227 cases of secondary amenorrhoea not preceded by treatment with combined tablets (group II). The two groups were collected during the same period. The average age of the patients was 4 years higher in group I than in group II. Oligomenorrhoea and previously occurred in 30% of group I and in 46% of group II. Pronounced predisposing factors., such as psychogenic trauma and stress with or without considerable change in body weight, were encountered in 26% in group I and 56% in group II. The incidence of increased urinary output of 17-keto steroids, 17-ketogenic steroids and of hirsutism was slightly higher in group II. The percentage of eosinophilic cells in vaginal scrapings was low in 20% in group I as compared with 46% in group II. Spontaneous return of pituitary-ovarian function occurred in 40% in both groups. Patients recovering spontaneously in group I presented a maximum during the first few months, followed by a steady and fairly uniform decline. Spontaneous recovery in group II was more or less independent of time. It seems reasonable to believe that oral contraceptives did promote or contribute to the development of secondary amenorrhoea in about 50%, representing cases with various predisposing factors. A causal relation between oral contraceptives and secondary amenorrhoea was indicated in the remaining 50% because of perfectly normal ovarian function before treatment and absence of predisposing factors.
During the past decade, family-planning programmes have been conducted on the assumption that developments in the field of contraception (e.g., hormonal contraceptives and intra-uterine devices) had reached a stage of considerable technical perfection. Enough information has now been accumulated, however, to indicate that this assumption was not fully justified; the high drop-out rates from these programmes observed under different conditions indicate that there is an urgent need for further improvements of the existing methods and for the development of new methods based on different approaches. A prerequisite for the development of such methods is a greatly improved knowledge of the physiological factors influencing the various steps of the reproductive processes in the human species.In an attempt to focus attention on the various steps which are susceptible to controlled interference, a brief review is given of some of the present concepts of the regulation of spermiogenesis, ovulation and the menstrual cycle, sperm capacitation, fertilization, tubal passage, zygote and blastocyst formation, implantation and early embryonic development. It is concluded that the reproductive processes are indeed subject to intricate biochemical and hormonal regulatory mechanisms and that the different phases of these processes do offer a variety of possibilities for hormonal, pharmacological and perhaps also immunological interference.
The cervical cap is a convenient, inexpensive, nonhormonal and non-invasive contraceptive method. This method has potential for better effectiveness if custom-fit caps are manufactured. As more health care providers become knowledgeable in the use of the cap, more women will become aware of this contraceptive method as an alternative to oral contraceptives and intrauterine devices. Research is needed to document the most accurate method of cervical cap fitting and the effectiveness rate of the cervical cap. Nurse practitioners who counsel patients and fit them for caps are in the perfect position to start doing this research.