The biochemistry of human endometrium after two regimens of postcoital contraception: a dl-norgestrel/ethinylestradiol combination or danazol

Emergency contraception

Despite significant declines over the past 2 decades, the United States continues to have teen birth rates that are significantly higher than other industrialized nations. Use of emergency contraception can reduce the risk of pregnancy if used up to 120 hours after unprotected intercourse or contraceptive failure and is most effective if used in the first 24 hours. Indications for the use of emergency contraception include sexual assault, unprotected intercourse, condom breakage or slippage, and missed or late doses of hormonal contraceptives, including the oral contraceptive pill, contraceptive patch, contraceptive ring (ie, improper placement or loss/expulsion), and injectable contraception. Adolescents younger than 17 years must obtain a prescription from a physician to access emergency contraception in most states. In all states, both males and females 17 years or older can obtain emergency contraception without a prescription. Adolescents are more likely to use emergency contraception if it has been prescribed in advance of need. The aim of this updated policy statement is to (1) educate pediatricians and other physicians on available emergency contraceptive methods; (2) provide current data on safety, efficacy, and use of emergency contraception in teenagers; and (3) encourage routine counseling and advance emergency-contraception prescription as 1 part of a public health strategy to reduce teen pregnancy. This policy focuses on pharmacologic methods of emergency contraception used within 120 hours of unprotected or underprotected coitus for the prevention of unintended pregnancy. Emergency contraceptive medications include products labeled and dedicated for use as emergency contraception by the US Food and Drug Administration (levonorgestrel and ulipristal) and the "off-label" use of combination oral contraceptives.

Updates in hormonal emergency contraception

In recent years, there have been many updates in hormonal emergency contraception. Levonorgestrel emergency contraception has been available for several years to prevent pregnancy when used within 72 hours after unprotected intercourse or contraceptive failure, and it was recently approved for nonprescription status for patients aged 17 years or older. Current research suggests that the primary mechanism of action is delaying ovulation. Ulipristal is the newest emergency contraception, available by prescription only, approved for use up to 120 hours after unprotected intercourse or contraceptive failure. The primary mechanism of action is delaying ovulation. When compared with levonorgestrel emergency contraception, ulipristal was proven noninferior in preventing pregnancy. Evidence suggests that ulipristal does not lose efficacy from 72-120 hours; however, more studies are warranted to support this claim. Many misconceptions and controversies about hormonal emergency contraception still exist. Research does not support that increased access to emergency contraception increases sexual risk-taking behavior. Several studies suggest that health care providers, including pharmacists, could benefit from increased education about emergency contraception. It is important for pharmacists to remain up-to-date on the most recent hormonal emergency contraception products and information, as pharmacists remain a major point of access to emergency contraception.

Postcoital contraception

As early as 1500 BC, history records women using a variety of drugs, devices and manoeuvres in an attempt to prevent pregnancy after intercourse has taken place. It was not until the 1960s however that scientific efforts were made to develop effective postcoital contraception (PCC). Whilst it had been known for over thirty years that a variety of compounds would inhibit implantation and embryonic development and interrupt pregnancy in the rabbit and the rat, experiments with primates had been less successful. In 1966 however, Morris and Van Wagenen reported the prevention of pregnancy in 28 macaque monkeys treated with oestradiol, diethylstilboestrol or a synthetic compound (ORF 3858), administered after mating. In the same paper – and confessing that they embarked upon human experimentation ‘with some trepidation’ – the authors reported that 50 mg diethylstilboestrol (DES) given for four to six days appeared to be effective in preventing pregnancy after intercourse had taken place in an undisclosed number of women who were the victims of rape.

Attitudes and beliefs about emergency contraception among patients at academic family medicine clinics

PURPOSE

The possible mechanisms of action of emergency contraception (EC) include preventing ovulation, fertilization, or implantation of an embryo. Differences in the use of terminology between medical personnel and the general public could be misleading to patients who would use EC. This cross-sectional survey evaluated women's beliefs regarding pregnancy and EC's possible mechanisms of actions.

METHODS

An anonymous questionnaire was developed and pilot tested for an appropriate reading level and ease of analysis. It collected information on demographics and beliefs about pregnancy and EC. During an 8-week period, the questionnaire was given to a convenience sample of female patients aged 18 to 50 years visiting 2 academic family medicine clinics in the southeastern United States. Descriptive statistics and logistic regression models were used for analysis.

RESULTS

A total of 178 women completed questionnaires. Nearly one-half (47%) of respondents believed that pregnancy begins with fertilization; however, less than one-third (30%) believed that life begins with fertilization. Thirty-eight percent of respondents stated that they would use EC only if they believed it worked before fertilization or implantation. Generally similar proportions thought that EC works before fertilization (24%) and before implantation (36%), or were unsure about when it works (34%). Younger age was associated with higher odds of believing that EC works before fertilization; none of the other demographic factors studied conferred either higher or lower odds.

CONCLUSIONS

Many women are uninformed about the possible mechanisms of action of EC, and we found no reliable predictors for those who were better informed. This study raises questions regarding women's understanding of EC and demonstrates the need to better educate them about its possible mechanisms of action.

Emergency contraception

Teen birth rates in the United States have declined during the last decade but remain much higher than rates in other developed countries. Reduction of unintended pregnancy during adolescence and the associated negative consequences of early pregnancy and early childbearing remain public health concerns. Emergency contraception has the potential to significantly reduce teen-pregnancy rates. This policy statement provides pediatricians with a review of emergency contraception, including a definition of emergency contraception, formulations and potential adverse effects, efficacy and mechanisms of action, typical use, and safety issues, including contraindications. This review includes teens' and young adults' reported knowledge and attitudes about hormonal emergency contraception and issues of access and availability. The American Academy of Pediatrics, as well as other professional organizations, supports over-the-counter availability of emergency contraception. In previous publications, the American Academy of Pediatrics has addressed the issues of adolescent pregnancy and other methods of contraception.

The role of emergency contraception

Emergency contraception is an underused therapeutic option for women in the event of unprotected sexual intercourse. Available postcoital contraceptives include emergency contraceptive pills (ECPs) both with and without estrogen, and copper-bearing intrauterine devices. Each method has its individual efficacy, safety, and side effect profile. Most patients will experience prevention of pregnancy, providing they follow the treatment regimen carefully. There are concerns that women who use ECPs may become lax with their regular birth control methods; however, reported evidence indicates that making ECPs more readily available would ultimately reduce the incidence of unintended pregnancies. In addition, it is typically conscientious contraceptive users who are most likely to seek emergency treatment. Patient education is paramount in the reduction of unintended pregnancies and there are numerous medical resources available to women to assist them in this endeavor. Finally, ECPs are associated with financial and psychologic advantages that benefit both the individual patient and society at large.

Emergency contraception and morality: reflections of health care workers and clients

In this study, we explore the retrospective reports of 21 US Planned Parenthood clients about their use of emergency contraception pills (ECPs) and the views of ten Planned Parenthood health care workers at two clinics about providing ECPs. We elucidate the sociological phenomena that frame emergency contraception usage: cultural ideology about contraception, sexuality, unintended pregnancy, and abortion. We focus on the ways in which interactions between health care workers and clients both mediate and reinforce such cultural ideology. Our research indicates that the distinctions between fertilization and pregnancy, between contraception and abortion, between responsible and irresponsible procreative behavior, are not hard and fast boundaries upon which everyone agrees. We illuminate the dividing lines and continuities our participants invoked, affirmed, and questioned when contemplating the continuum from potential fertility to realized (and unwanted) pregnancy.

Emergency contraception--clinical and ethical aspects

Emergency contraception (EC) consists of either 1.5 mg of levonorgestrel (LNG) in one or two doses, or a combination of LNG with ethinylestradiol, administered for up to 5 days after unprotected intercourse. Clinical studies indicate that LNG alone is more effective and has less side effects. Its effectiveness decreases the longer after coitus it is taken. EC is indicated when there is non-compliance or accidents with the use of regular methods of contraception, or when women have had voluntary or imposed unprotected intercourse. The ethics of providing EC has been questioned by some, arguing that it acts by preventing implantation. Scientific evidence does not support this concept, but shows that EC acts mostly before fertilization. Placing obstacles to the access of EC is unethical as it transgresses the ethical principles of autonomy, non-maleficence beneficence and justice. Far from inducing abortions, EC reduces unwanted pregnancies and prevents abortion.

Effectiveness of the Yuzpe regimen of emergency contraception by cycle day of intercourse: implications for mechanism of action

OBJECTIVE

The purpose of this study was to provide evidence about the mechanism of action of the Yuzpe method of emergency contraception by examining effectiveness by cycle day of intercourse relative to ovulation.

METHODS

Through a literature search, we identified eight studies that present the number of women treated and outcome of treatment by cycle day of unprotected intercourse relative to expected day of ovulation. Using five sets of external estimates of conception probabilities by cycle day of intercourse among women not using contraception, we assessed and compared the effectiveness of the Yuzpe regimen by whether intercourse occurred on or before the second day before ovulation or afterward, and whether intercourse occurred on or before the first day before ovulation or afterward.

RESULTS

In 36 of the 45 pairs of estimates of effectiveness, based on eight separate studies and the eight studies combined and five different sets of conception probabilities by cycle day, effectiveness was higher-and in most cases substantially higher-when intercourse occurred on or before the second day before ovulation (day -2) than when it occurred later. When data were stratified by whether intercourse occurred on or before the day before ovulation (day -1), effectiveness was greater when intercourse occurred early in 43 of 45 pairs.

CONCLUSIONS

These results suggest that one hypothesized mechanism of action of the Yuzpe method, inhibiting implantation of a fertilized egg, is unlikely to be the primary mechanism of action.

Emergency contraception

The last decade has seen a huge interest in emergency contraception (EC) because of the potential it has to reduce abortion rates. A variety of hormonal methods is available although mifepristone-arguably the best method-is only licensed in China. The intrauterine device is highly effective but its use is limited because of the technical skill required for successful insertion. The mechanism of action of both the Yuzpe regimen of EC and of levonorgestrel is poorly understood and for all methods there are serious methodological difficulties involved with calculating efficacy. Nevertheless the risks and side-effects of EC are negligible and the practicalities of prescribing it are extremely simple. Research and programmatic efforts should concentrate on improving availability if EC is to fulfil its promise as a public health intervention to reduce unwanted pregnancy.

Postfertilization effect of hormonal emergency contraception

OBJECTIVE

To assess the possibility of a postfertilization effect in regard to the most common types of hormonal emergency contraception (EC) used in the US and to explore the ethical impact of this possibility.

DATA SOURCES AND STUDY SELECTION

A MEDLINE search (1966-November 2001) was done to identify all pertinent English-language journal articles. A review of reference sections of the major review articles was performed to identify additional articles. Search terms included emergency contraception, postcoital contraception, postfertilization effect, Yuzpe regimen, levonorgestrel, mechanism of action, Plan B.

DATA SYNTHESIS

The 2 most common types of hormonal EC used in the US are the Yuzpe regimen (high-dose ethinyl estradiol with high-dose levonorgestrel) and Plan B (high-dose levonorgestrel alone). Although both methods sometimes stop ovulation, they may also act by reducing the probability of implantation, due to their adverse effect on the endometrium (a postfertilization effect). The available evidence for a postfertilization effect is moderately strong, whether hormonal EC is used in the preovulatory, ovulatory, or postovulatory phase of the menstrual cycle.

CONCLUSIONS

Based on the present theoretical and empirical evidence, both the Yuzpe regimen and Plan B likely act at times by causing a postfertilization effect, regardless of when in the menstrual cycle they are used. These findings have potential implications in such areas as informed consent, emergency department protocols, and conscience clauses.

Emergency contraception: the nurse's role in providing postcoital options

Emergency contraception refers to pregnancy prevention methods initiated after unprotected sexual intercourse. Research has shown that 75% of the 3.5 million unintended pregnancies that occur in the United States every year could be prevented through use of emergency contraception. Hormonal methods and postcoital insertion of intrauterine devices have been shown to be safe and effective. Nurses play an essential role in the distribution of emergency contraception as patient educators, advocates, and support persons.

The emergency contraceptive pill: a survey of knowledge and attitudes among students at Princeton University

OBJECTIVE

Our purpose was to measure and analyze knowledge and attitudes about emergency contraceptive pills. The hypothesis we tested was that more accurate knowledge about the regimen would be associated with favorable attitudes towards its use.

STUDY DESIGN

We conducted a random sample telephone survey and a series of focus group discussions at Princeton University (results for 11 focus groups are presented elsewhere) A total of 550 undergraduate and graduate students were selected randomly for participation in the survey, and the response rate was 82%. The study's primary outcome measure was attitudes toward the emergency contraceptive pill as a method of fertility control. We used multivariate regression analysis with ordered logit models to test the hypothesized association between knowledge and attitudes.

RESULTS

Basic awareness and approval of the emergency contraceptive pill were widespread, yet students lacked detailed knowledge, which did contribute to health and ethical misgivings about the regimen. Students with accurate information, especially those students who knew that the therapy is a large dose of regular oral contraceptives and that side effects are generally minor, were significantly more likely than others to report favorable attitudes. Many students confused the pills dispensed by the university health services (Oral, Wyeth-Ayerst, Philadelphia) with the abortifacient RU 486. Students noted discussion of the method is rare, and many wanted to know more about it. Statistical results are reported with a 95% confidence level.

CONCLUSIONS

Educational efforts should offer specific information about the composition of emergency contraceptive pills, the side effects, and how the regimen works.

The morning-after pill--how long after?

Postcoital contraception has been prescribed for more than two decades. The current regimen is given within 72 hours of unprotected intercourse. After this period, not many choices remain; either the woman may wait until her next menses hoping she is not pregnant or she may have a postcoital intrauterine contraceptive device inserted. Since these alternatives are not always acceptable, we reviewed the literature looking for evidence supporting the current maximum time limit for treatment. Our conclusion is that the limit could theoretically be extended; therefore we think it is time to challenge the time period of current treatment by conducting clinical trials.

Hormonal postcoital contraception with an ethinylestradiol-norgestrel combination and two danazol regimens

The ethinylestradiol-norgestrel combination (EE-NG) for postcoital contraception, as described by Yuzpe, has been shown to be an effective method but with frequent side effects. To overcome the problem of adverse effects a new approach using danazol was proposed, but the efficacy and acceptability of this treatment have not yet been tested in large studies. In a 5-year period at the AIECS Family Planning Centre in Milan we treated 2448 women requesting postcoital contraception using Yuzpe's regimen and two danazol regimens (800 mg/1200 mg). The patients' acceptability for danazol treatment was higher than for Yuzpe's regimen due to fewer, milder and shorter side effects. Nine pregnancies occurred in the EE-NG group (2.21%), 17 in the 800 mg group (1.71%) and 6 in the 1200 mg group (0.82%). Our study shows a statistically significant efficacy against expected pregnancy rates both with Yuzpe's regimen and with danazol. The 1200 mg danazol treatment seems to be more effective and can be considered a valid alternative to the EE-NG combination for hormonal postcoital contraception.