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PubMed2002

Genetic polymorphisms modify the response of factor VII to oral contraceptive use: an example of gene-environment interaction.

Elevated plasma levels of factor VII and fibrinogen are risk factors for cardiovascular disease, especially arterial thrombosis. Oral contraceptive use increases factor VII and fibrinogen plasma levels. It has been described that DNA polymorphisms are associated with the plasma levels of hemostatic variables and their regulation. The R/Q353 polymorphism in the factor VII gene and the -455G/A polymorphism in the fibrinogen beta-gene are associated with plasma levels of factor VII and fibrinogen, respectively. We analysed data of a randomised study (n = 95) in which two types of oral contraceptives were compared with regard to their effect on factor VII and fibrinogen, in which we also determined R/Q353 and -455G/A polymorphisms. Women were allocated randomly to either receiving a monophasic oral contraceptive containing 75 micrograms of gestodene and 20 micrograms of ethinyl estradiol, or 150 micrograms of desogestrel and 20 micrograms of ethinyl estradiol. Blood was taken before treatment and after 3 and 6 months of oral contraceptive use. Factor VII and fibrinogen increased significantly after 3 and 6 months of oral contraceptive use; the increase in factor VII was higher in the desogestrel group than in the gestodene group at 3 and 6 months. For fibrinogen, there were no intergroup differences at 3 and 6 months. At baseline, an association between genotype and plasma factor VII and fibrinogen levels was observed. In multivariate analysis, the R/Q353 polymorphism and the type of oral contraceptive were determinants of the effect on the change in factor VII, with the highest increase in women carrying the Q allele and using the desogestrel-containing oral contraceptive, and the lowest increase in women with the RR genotype who use the gestodene-containing oral contraceptive. For fibrinogen, no interaction among type of oral contraceptive, -455G/A polymorphism, and change in plasma levels was observed. We conclude that an individual's genetic variation may contribute to the response of plasma factor VII to oral contraceptive use.

Adult↗
PubMed2002

Canadian physicians' role in contraception from the 19th century to now.

Birth control techniques were widely available in 19th-century Canada, despite the fact that they were illegal. Most physicians remained silent about contraception, with a small minority vocally opposed to the practice of birth control. Canadian physicians were influenced by the social, economic, legal, and political values of their time, and their support of birth control initially lagged far behind public interest and need. At later points in Canadian medical history, physicians actively supported increased access to contraceptive services, and played a significant role in the legalization of contraception in this country. The Canadian birth control movement made tremendous strides in the 1930s with the dissemination of contraceptive information to the public and the opening of the first public birth control clinic. The Canadian Medical Association supported contraceptive practice as part of preventive medicine in the 1930s, and the legalization of contraception in the early and mid 1960s. Contraception was formally legalized in Canada in 1969 and has become a significant aspect of medical practice. In Canada, current medical controversies in contraception include issues of public education, advertising, contraceptive research, and the integration of contraception with other aspects of reproductive and sexual health in medical practice.

Canada↗
PubMed2003

Renal hemodynamic and tubular responses to salt in women using oral contraceptives.

BACKGROUND: The use of oral contraceptives is associated with an increased risk of developing hypertension but the mechanisms of this hypertensive effect are not completely defined. The purpose of the present study was to assess prospectively the systemic and renal hemodynamic and tubular responses to salt in women taking oral contraceptives. METHODS: Twenty seven young healthy normotensive women taking oral contraceptives containing monophasic combination of 30 microg ethynilestradiol and 150 microg desogestrel for>6 months were enrolled. All women were assigned at random to receive a low (40 mmol/day) or a high (250 mmol/day) sodium diet for 1 week on two consecutive menstrual cycles during the active oral contraceptive phase. At the end of each diet period, 24-hour ambulatory blood pressure, renal hemodynamics, sodium handling, and hormonal profile were measured. RESULTS: The blood pressure response to salt on oral contraceptives was characterized by a salt-resistant pattern with a normal circadian rhythm. Salt loading results in an increase in glomerular filtration rate (GFR) (P < 0.05 vs. low salt), with no change in the renal plasma flow, thus leading to an increase in the filtration fraction (P < 0.05). At the tubular level, women on oral contraceptives responded to a low salt intake with a marked increased in proximal sodium conservation (P < 0.01 vs. high salt) and with an almost complete reabsorption of sodium reaching the distal tubule. After sodium loading, both the proximal and the distal reabsorption of sodium decreased significantly (P < 0.01). CONCLUSION: The use of oral contraceptives is not associated with an increased blood pressure response to salt in young normotensive women. However, oral contraceptives affect the renal hemodynamic response to salt, a high salt intake leading to an increase in GFR and filtration fraction. This effect is possibly mediated by the estrogen-induced activation of the renin-angiotensin system. Oral contraceptives also appear to increase the tubular responsiveness to changes in sodium intake. Taken together, these data point out evidence that synthetic sex steroids have a significant impact on renal function in women. The renal effects of oral contraceptives should be taken into account when managing young women with renal diseases.

Adult↗
PubMed2000

No sex-related differences but significant inhibition by oral contraceptives of CYP2C19 activity as measured by the probe drugs mephenytoin and omeprazole in healthy Swedish white subjects.

BACKGROUND: Although it is known that the use of oral contraceptives inhibits oxidative drug metabolism, there is little information regarding their effect on CYP2C19 activity. Moreover, earlier reports suggest that there may be differences in CYP2C19 activity between men and women. OBJECTIVE: We sought to assess the effect of sex and intake of oral contraceptives on CYP2C19 activity as measured by the probe drugs mephenytoin and omeprazole. METHODS: To determine CYP2C19 activity in white Swedish subjects, 644 subjects previously phenotyped with mephenytoin and 175 subjects phenotyped with omeprazole were investigated. The 8-hour urinary mephenytoin S/R ratio after ingestion of 100 mg mephenytoin and the plasma concentration ratio of omeprazole/hydroxyomeprazole at 3 hours after ingestion of 20 mg omeprazole were used as measures of CYP2C19 activity. Differences in these ratios and in their frequency distributions were then examined among women with and without oral contraceptives and men. In addition, nearly all subjects in the omeprazole group had been genotyped with regard to the CYP2C19*2 (ml) allele. Subjects homozygous for the CYP2C19*2 allele were excluded from the study. RESULTS: The median mephenytoin S/R ratio was 2.5-fold higher in the subgroup of women taking oral contraceptives compared with either women not taking oral contraceptives (P < .001) or men (P < .001). Similarly, the mean omeprazole/hydroxyomeprazole ratio was twice as high in the oral contraceptive group compared with women not taking oral contraceptives (P < .001) or men (P < .001). However, no differences were evident between women not taking oral contraceptives and men in either the mephenytoin group (P = .48) or the omeprazole group (P = .77). The oral contraceptive-induced inhibitory effect on CYP2C19 activity was similar between the CYP2C19*1/*1 and *1/*2 genotypes, and they were independent of age. CONCLUSIONS: Intake of oral contraceptives significantly inhibits CYP2C19 activity, but there is no true sex-related difference in CYP2C19 activity in healthy, white, Swedish subjects.

Adolescent↗
PubMed2002

Oral contraceptives and the risk of breast cancer in BRCA1 and BRCA2 mutation carriers.

BACKGROUND: Oral contraceptive use has been associated with an increase in the risk of breast cancer in young women. We examined whether this association is seen in women at high risk of breast cancer because they carry a mutation in one of two breast cancer susceptibility genes, BRCA1 and BRCA2. METHODS: We performed a matched case-control study on 1311 pairs of women with known deleterious BRCA1 and/or BRCA2 mutations recruited from 52 centers in 11 countries. Women who had been diagnosed with breast cancer were matched to control subjects by year of birth, country of residence, mutation (BRCA1 or BRCA2), and history of ovarian cancer. All study subjects completed a questionnaire about oral contraceptive use. Odds ratios (ORs) and 95% confidence intervals (CIs) were derived by conditional logistic regression. All statistical tests were two-sided. RESULTS: Among BRCA2 mutation carriers, ever use of oral contraceptives was not associated with an increased risk of breast cancer (OR = 0.94, 95% CI = 0.72 to 1.24). For BRCA1 mutation carriers, ever use of oral contraceptives was associated with a modestly increased risk of breast cancer (OR = 1.20, 95% CI = 1.02 to 1.40). However, compared with BRCA1 mutation carriers who never used oral contraceptives, those who used oral contraceptives for at least 5 years had an increased risk of breast cancer (OR = 1.33, 95% CI = 1.11 to 1.60), as did those who used oral contraceptives before age 30 (OR = 1.29, 95% CI = 1.09 to 1.52), those who were diagnosed with breast cancer before age 40 (OR = 1.38, 95% CI = 1.11 to 1.72), and those who first used oral contraceptives before 1975 (OR = 1.42, 95% CI = 1.17 to 1.75). CONCLUSIONS: Among BRCA1 mutation carriers, women who first used oral contraceptives before 1975, who used them before age 30, or who used them for 5 or more years may have an increased risk of early-onset breast cancer. Oral contraceptives do not appear to be associated with risk of breast cancer in BRCA2 carriers, but data for BRCA2 carriers are limited.

Adolescent↗
PubMed1989

Oral contraceptives and vascular disease.

This update on the cardiovascular risks of oral contraceptives unfortunately adds little to our original 1982 review for the following reasons: 1) There are many different formulations on the market, and they keep changing; 2) Women often use different formulations, stopping and starting as well as switching; 3) The statistical power of the studies often does not permit analyses by specific formulations; 4) The required information (brand name) is sometimes not collected or not collected reliably; 5) Apparently few case-control studies are being conducted to address these issues. Data that are available, interpreted cautiously, suggest either a continuance of the previously observed risk or a small to modest diminution with the use of the newer oral contraceptive formulations. The earlier advice to physicians still seems prudent and is briefly stated: 1) Try to avoid prescribing oral contraceptives for women over 35 years of age; 2) Women who smoke cigarettes should avoid using oral contraceptives, and users should not smoke; 3) Prescribe the formulation with the lowest dose and/or potency of estrogen that is effective and that does not cause unacceptable "breakthrough" bleeding; 4) Women with hypertension should be carefully monitored, and women who develop hypertension while on oral contraceptives should be switched to another form of contraception, if possible. Although oral contraceptives are the most effective form of contraception currently widely available, all risks of a contraceptive method must be compared with corresponding measures of effectiveness and with the risks of unwanted pregnancy. In particular, oral contraceptive users can reduce their risk of myocardial infarction by a reduction or elimination of cigarette smoking.

Adult↗
PubMed2004

The effect of hormonal contraception on genital tract shedding of HIV-1.

OBJECTIVE: A previous cross-sectional study reported that hormonal contraception may be associated with increased infectivity in HIV-1 infected women. We conducted a prospective study to determine if cervical shedding of HIV-1 increased after initiating hormonal contraception. DESIGN: Shedding of HIV-1 DNA (a marker of HIV-1 infected cells) and HIV-1 RNA were measured before and after initiating hormonal contraception. METHODS: HIV-1 seropositive women were recruited from a Kenyan family planning clinic. At baseline, cervical secretions were collected for HIV-1 DNA and RNA assays in women initiating hormonal contraception; follow-up samples were collected a median of 64 days later. RESULTS: One-hundred and one women chose depot medroxyprogesterone (Depo), 53 chose low-dose oral contraceptives (OC), seven high-dose OC, and 52 progesterone-only OC. At follow-up, there was a significant increase in the prevalence of cervical HIV-1 DNA detection [from 42% to 52%, odds ratio (OR), 1.62; 95% confidence interval (CI), 1.03-2.63) for all hormonal contraception combined, and a trend for an increase for each individual type. Although the prevalence of cervical HIV-1 RNA increased slightly (from 82% to 86%; OR, 1.56; 95% CI, 0.83-3.03), the concentration of cervical HIV-1 RNA did not change significantly overall (from 2.81 to 2.84 log10 copies/swab; P = 0.77) or for individual contraception types. CONCLUSIONS: A modest but significant increase in shedding of HIV-1 DNA but not of HIV-1 RNA was detected after starting hormonal contraception. Our results may have important implications regarding the infectivity of women using hormonal contraception, and highlight the need for epidemiologic studies of transmission rates from women using and not using hormonal contraception.

Adolescent↗
PubMed2003

Married women's satisfaction with their choice of contraception.

Fertility reduction has been promoted in Taiwan for almost 40 years. However, little research has been done into women's satisfaction with the methods of contraception they use. The purpose of this study is to explore their level of satisfaction, along with the related factors of demographic data, giving birth and types of contraceptives used. Employing a cross-sectional design, self-administered questionnaires were distributed to women in the northern area of Taiwan. Purposive sampling was used to collect data from 97 women. The results reveal a mean age of 37.21 years. The mean length of marriage was 13.53 years. The majority (43.29 %) of the subjects were graduates of high school or vocational school. Of the subjects, 92.78 % had given birth, while 35.05 % had experienced abortion. IUDs (Intrauterine Devices) were the most commonly used form of contraceptive, while 63.92 % used other types. Satisfaction was divided into four categories: satisfaction with contraceptive services, satisfaction with contraceptive knowledge source, satisfaction with contraceptive experience and satisfaction with spousal support. Overall, subjects were happy with the contraceptive methods they used. There was no statistical difference in satisfaction between demographic variances, fertility or contraceptive methods applied. Though subjects showed satisfaction with contraception, we feel women's subjective experiences should be investigated in order to promote even better satisfaction. Possible future studies could include random sampling and an examination of the related factors of contraceptive satisfaction.

Adult↗
PubMed2000

Contraception in women at high risk or with established cardiovascular disease.

Oral contraceptives are one of the most effective and widely used reversible contraceptive methods. Over 90 million women worldwide, including over 44 million in developing countries, are now using oral contraceptives. Despite their advantages, there is concern about the links between combined oral contraceptives and the risk of cardiovascular disease. The risk attributable to oral contraceptive use in women < 35 years of age is small, even if they smoke, but there are substantially increased risks in older women who both smoke and use oral contraceptives. Differences between oral contraceptive types in the relative risk of venous thromboembolism contribute little to the total cardiovascular mortality associated with oral contraceptive use, even though the total number of cardiovascular events is increased. It is important to consider the user's age and smoking status when determining oral contraceptive-attributable risks. Hormonal oral contraceptives have changed and now contain lower doses of estrogen and progestagen.

Adult↗
PubMed2003

Decreased maximal aerobic capacity with use of a triphasic oral contraceptive in highly active women: a randomised controlled trial.

BACKGROUND: Oral contraceptives are commonly used by women athletes. However, their effect on athletic performance is unclear. OBJECTIVES: To examine the effects of a moderate dose, triphasic oral contraceptive on measures of athletic performance in highly trained women athletes. METHODS: This is a double blind, placebo controlled trial in 14 women with ovulatory menstrual cycles and maximal aerobic capacity (VO(2)MAX) >/==" BORDER="0">50 ml/kg/min. Four measures of athletic performance were tested: VO(2)MAX, anaerobic capacity (anaerobic speed test), aerobic endurance (time to fatigue at 90% of VO(2)MAX), and isokinetic strength (Cybex II dynamometer). Height, weight, and six skinfold measurements were also recorded. All these observational tests were completed during both the follicular and mid-luteal phases of an ovulatory menstrual cycle. Cycle phases were confirmed by assaying plasma oestradiol and progesterone. Participants were subsequently randomly assigned to either a tricyclic oral contraceptive or placebo and retested in identical fashion (oral contraceptive phase). RESULTS: Absolute and relative changes in VO(2)MAX from follicular to oral contraceptive phase decreased in the oral contraceptive group by 4.7%, whereas the placebo group showed a slight increase (+1.5%) over the same time period. Two of the women taking oral contraceptive had decreases of 4 and 9 ml/kg/min. In contrast, most women in the placebo group improved or maintained VO(2)MAX. There was also a significant increase in the sum of skinfolds in women taking oral contraceptive compared with those taking placebo (p<0.01). There were no significant changes in other physiological variables (maximum ventilation, heart rate, respiratory exchange ratio, packed cell volume) or measures of performance (anaerobic speed test, aerobic endurance, isokinetic strength) as a function of oral contraceptive treatment. CONCLUSIONS: The decrease in VO(2)MAX that occurs when oral contraceptive is taken may influence elite sporting performance in some women. Further studies are required to determine the mechanisms of this change.

Adolescent↗
PubMed1992

Chlamydia trachomatis and oral contraceptive use: a quantitative review.

OBJECTIVES: Chlamydia trachomatis is now recognised as a major sexually transmitted disease; oral contraceptive use is rapidly increasing particularly in developing countries. There are thus important public health implications of the many reports that isolation of C trachomatis is more frequent among users of oral contraceptives. The aim of this analysis was to assess the strength and consistency of this association by summarising published studies between 1972 and 1990. DESIGN: Studies identified were grouped according to whether they were prospective or case-control studies. Data were extracted and pooled estimates of the unadjusted odds ratios were made for all studies, as well as for sub-groups defined by an index of study quality, background prevalence of C trachomatis, and the contraceptive comparison being made. LOCATION: Studies in the analysis were mainly conducted in Europe and North America; the meta-analysis was done at the Harvard School of Public Health, Boston, MA, USA. RESULTS: The pooled estimated unadjusted odds ratio for 29 case-control studies examined was 1.93 (95% CI, 1.77-2.11), indicating an almost twofold increased risk of chlamydial infection for oral contraceptive users. Neither study quality nor prevalence of C trachomatis modified this risk. When compared to the use of barrier contraceptives, however, the risk of infection for women using oral contraceptives increased to 2.91 (95% CI, 1.86-4.55). The pooled estimated protective effect of barrier methods in these studies was 0.34 (95% CI, 0.22-0.54). CONCLUSIONS: Cross-study comparisons of the relationship between oral contraceptive use and chlamydial infection are limited by the design and analysis of many component studies which did not control for confounding factors such as sexual behaviour and age. The almost twofold risk of increased chlamydial infection for oral contraceptive users, supported by the findings of two prospective studies, however, points to the importance of considering the risks and benefits of oral contraceptive use in women who are likely to be exposed to C trachomatis and other STDs. The protective effect of barrier methods emphasizes the continued need for promoting barrier methods of contraception.

Case-Control Studies↗
PubMed2006

Contraceptive use and pregnancy risk among U.S. high school students, 1991-2003.

CONTEXT: Trends in teenagers' contraceptive use have received less attention than trends in adolescent sexual intercourse, despite the importance of contraceptive use to preventing teenage pregnancy. METHODS: Sexually active high school students' use of contraceptives and risk of pregnancy from 1991 to 2003 were examined using data from the national Youth Risk Behavior Survey and published contraceptive failure rates. Changes in pregnancy risk were assessed using weighted least-squares regression. RESULTS: Between 1991 and 2003, contraceptive use improved among sexually active U.S. high school students. Improvements among women included an increase in the proportion reporting condom use at last sex (from 38% to 58%) and declines in the proportions using withdrawal (from 19% to 11%) and no method (18% to 12%). Hormonal method use changed little, as a decline in pill use (from 25% to 20%) was offset by use of injectables (5% in 2003). Similar patterns were found among men. Women's risk of pregnancy declined 21% over the 12 years. The largest improvements in contraceptive use and pregnancy risk occurred among ninth graders, and whites and blacks. In 2003, 46% of pregnancy risk resulted from failure to use any method of contraception, and 54% resulted from contraceptive failure. CONCLUSIONS: Improvement in the use of contraceptives by sexually active high school students during the 1990s is encouraging. To sustain this trend, programs need to encourage contraceptive use among teenagers who do not use it and to stress consistent and correct use among those who do.

Adolescent↗
PubMed2002

Revisiting a pilot survey involving contraception and teenage pregnancy in Ayrshire and Arran.

CONTEXT: How to respond to the challenge of reducing unplanned pregnancy rates in Ayrshire and Arran. OBJECTIVES: (1) To improve understanding of the educational needs of 11-15-year-olds regarding contraception which could be used to inform planning of future sex education in schools in Ayrshire and Arran. (2) To put this in context by reviewing contraceptive usage amongst 14-16-year-old pregnant teenagers. DESIGN: (1) A questionnaire given to 11-15-year-olds during a sex education class. (2) A retrospective study of pregnant 14-16-year-olds. PARTICIPANTS: (1) School pupils aged 11-15 from an area of mixed social background (n = 80). (2) Pregnant 14-16-year-olds presenting at Ayrshire Central Maternity Hospital between September 1997 and March 1998 (n = 74). RESULTS: (1) Ninety-nine percent of the teenagers said they would use contraception. Seventy-three percent of girls, but only 52% of boys, were aware of the services available. Ninety percent of girls knew about emergency contraception, but only 59% of boys. Thirty-three percent thought they received too little sex education at school. Thirty-two percent received no sex education from home, and 10% 'too little'. More information about sexually-related diseases, safe sex and having a baby was requested. (2) The study of pregnant teenagers showed that 69% went ahead with their pregnancies, that 71% were not habitually using contraception and only 4% were using contraception at the time of conception. DISCUSSION: Teenagers said they would use contraception. However, boys were not aware of local services giving advice and help to young people, nor about emergency contraception. Teenagers felt they had no or 'too little' sex education at home. They felt too young to become a parent and be 'tied down'. CONCLUSIONS: (1) Teenagers at school want information about a wider range of sexual issues. (2) There is a gap between learning about contraception and its practical use, including emergency contraception. (3) Discussion and reinforcement of sex education at home may not exist for many teenagers. (4) Teenagers at school felt that they were not ready to be parents as this would restrict their social lives and disrupt their education. (5) It is recognised that young men are less well-informed than young women are, and this could impact on safe sex.

Adolescent↗
PubMed2006

Contraceptive awareness among men in Bangladesh.

OBJECTIVE: A considerable gap exists between contraceptive awareness and use. Traditional approaches to measuring awareness are inadequate to properly understand the linkages between awareness and use. The objective of this study was to examine the degree of men's modern contraceptive awareness in Bangladesh and the associated determinants and further testing of a hypothesis that current contraceptive use confers a high degree of method awareness. METHODS: This study used the couple data set from the Bangladesh Demographic and Health Survey (1999-2000). A two-level, multinomial logistic regression was used with the degree of contraceptive awareness as the dependent variable. The degree of awareness was measured by the reported number of modern contraceptive methods known among men aged 15-59 years. Men's responses on method awareness were classified according to those reported spontaneously and probed. RESULTS: Nearly 100% of the study participants reported having heard of at least one method and about half reported awareness of at least eight different methods of contraception. Multinomial logistic regression analyses showed that older and educated men were more likely to have reported a high degree of awareness. The findings confirmed our hypothesis that current contraceptive use is likely to confer a high degree of modern method awareness among men (p<0.001), after controlling for other important characteristics. CONCLUSIONS: Men who had a low degree of contraceptive awareness seem not properly informed of the wide range of contraceptive options. It is imperative that family planning intervention strategies in Bangladesh should focus on the degree and functional knowledge of contraceptive methods to improve the uptake of especially male-based modern methods.

Adolescent↗
PubMed1980

Adolescent contraceptive use: comparisons of male and female attitudes and information.

Information and attitudes about contraception and pregnancy were assessed with a self-administered questionnaire in a sample of urban Black teenagers. Data were obtained from 607 male and female students in high school health classes and a demographically similar group of 123 never-pregnant teenage women in a family planning clinic who had not attended these classes. Males were less likely to recognize the risk of pregnancy, had less information about contraceptives, and fewer attitudes that supported contraceptive use than females who participated in the same shool health classes. More males than females indicated that school classes had been the main source of contraceptive information. Teenage women in the family planning clinic did not differ from the high school females in attitudes about contraceptives, but the school group had somewhat more contraceptive information. The female school group was more likely to have discussed contraception with parents, obtained more contraception information from their mothers, and discussed contraception more with male friends than the teenagers who requested contraceptives at the family planning clinic.

Adolescent↗
PubMed2000

Occlusive vascular diseases in oral contraceptive users. Epidemiology, pathology and mechanisms.

Despite being an unprecedented departure from normal physiology, the combined oral contraceptive is not only highly effective, but it also has a remarkably good safety record. Concerns over safety persist, though, particularly with regard to venous thromboembolism (VTE), stroke and myocardial infarction (MI). Epidemiological studies consistently show an increase in risk of VTE, but the results are more contentious with regard to arterial diseases. Despite 40 years of research, the mechanisms behind these adverse effects are not understood. In this review, we integrate information from published studies of the epidemiology and pathology of the occlusive vascular diseases and their risk factors to identify likely explanations for pathogenesis in oral contraceptive users. Oral contraceptives induce both prothrombotic and fibrinolytic changes in haemostatic factors and an imbalance in haemostasis is likely to be important in oral contraceptive-induced VTE. The complexity of the changes involved and the difficulty of ascribing clinical significance has meant that uncertainty persists. A seriously under-researched area concerns vascular changes in oral contraceptive users. Histologically, endothelial and intimal proliferation have been identified in women exposed to high plasma estrogen concentrations and these lesions are associated with thrombotic occlusion. Other structural changes may result in increased vascular permeability, loss of vascular tone and venous stasis. With regard to arterial disease risk, epidemiological information relating to dose effects and joint effects with other risk factors, and studies of pathology and changes in risk factors, suggests that oral contraceptive use per se does not cause arterial disease. It can, nevertheless, synergise very powerfully with subclinical endothelial damage to promote arterial occlusion. Accordingly, the prothrombotic effects of the oral contraceptive estrogen intervene in a cycle of endothelial damage and repair which would otherwise remain clinically silent or would ultimately progress - in, for example, the presence of cigarette smoking or hypertension - to atherosclerosis. Future work in this area should focus on modification of the effects of established risk factors by oral contraceptive use rather than modification of the supposed risk of oral contraceptive use by established risk factors. Attempts to understand vascular occlusion in oral contraceptive users in terms of the general features of VTE or with reference to atherosclerosis may be limiting, and future work needs to acknowledge that such occlusions may have unique features. Unequivocal identification of the mechanisms involved would contribute considerably to the alleviation of fears over vascular disease and to the development of even safer formulations.

Adult↗
PubMed2000

Economic analysis of long-term reversible contraceptives. Focus on Implanon.

OBJECTIVE: To examine the economic impact of a new implantable contraceptive, Implanon, in comparison with other available contraceptive methods. DESIGN: This was a modelling study using cost data derived from national published sources and effectiveness data from either controlled clinical trials (Implanon) or reports in the literature (other contraceptives). In the baseline analysis, Implanon was compared with 2 long term reversible contraceptives, Norplant and Mirena. Further analyses were then carried out comparing Implanon with Depo-Provera and with combined oral contraceptives. SETTING: The study concentrated on the UK, but also made reference to several other European countries. MAIN OUTCOME MEASURES AND RESULTS: The baseline analysis showed that all 3 long term reversible contraceptives produce very good rates of return, with Implanon providing the best rate of return (both average and internal) of the 3 methods. The payback period for Implanon was calculated as 146 days, compared with 339 and 368 days for Norplant and Mirena, respectively. In terms of cost effectiveness, the cost per protected year for Implanon was 95 Pounds, compared with 146 Pounds and 168 Pounds for Norplant and Mirena, respectively. In comparison with Depo-Provera (an injectable contraceptive), Implanon was both less costly and more effective, the cost per protected year for Depo-Provera being 131 Pounds. The threshold beyond which Implanon delivers cost savings compared with combined oral contraceptives was at a failure rate of 4.9% for the combined pill. CONCLUSIONS: Reversible long term approaches to contraception provide an effective and efficient use of healthcare resources and generate an excellent return on public investment. Implanon produces better rates of return than both Norplant and Mirena, and is also more cost effective in terms of cost per pregnancy avoided and cost per protected year than Norplant, Mirena, Depo-Provera and oral contraceptives.

Adult↗
PubMed2000

Yasmin--a new oral contraceptive, a new progestogen: the reasons why.

There are over 60 million women using oral contraceptives worldwide, yet there are wide differences between different countries in the use of oral contraceptives and, in particular, in discontinuation rates. Large differences in rates of sterilization and of teenage pregnancy also highlight the fact that there are considerable geographical differences in oral contraceptive use. There are probably many reasons for these differences, including lack of information about the non-contraceptive benefits of oral contraceptives, differences in national health-care policies and systems, women's fears about side-effects and possible side-effects, and social, cultural and religious differences. In order to provide better choices of oral contraceptives, there is a need to consider new oral contraceptives, such as Yasmin (Schering AG, Berlin, Germany), which is formulated with ethinylestradiol and drospirenone, a progestogen which is pharmacologically very similar to progesterone. Unlike other progestogens, drospirenone is associated with weight stability or slight weight loss due to less water retention, one of the factors which is known to be of great importance in supporting compliance with oral contraceptives. Drospirenone also shares with some other progestogens the capacity to improve acne and seborrhea in hyperandrogenic women. Taken together, these properties make it likely that the combination of ethinylestradiol with drospirenone will contribute to improving oral contraceptive compliance, thereby maximizing the overall benefits of oral contraception.

Androstenes↗