Mode of action of dl-norgestrel and ethinylestradiol combination in postcoital contraception. III. Effect of preovulatory administration following the luteinizing hormone surge on ovarian steroidogenesis

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.

Emergency contraception - knowledge and attitudes in a group of Australian university students

OBJECTIVE

To explore first year Australian university students' knowledge and attitudes about emergency contraception and their understanding of the risk for pregnancy.

METHOD

A self-report questionnaire was completed by a convenience sample of 627 first year on-campus students from both health and non-health disciplines.

RESULTS

Knowledge about emergency contraception (EC) was generally poor including misunderstanding that it can only be used the 'morning after', as well as where it may be accessed. Its potential use was, however, more highly accepted as a preventative measure after unprotected sexual intercourse than abortion in the event of unplanned pregnancy. Women had better knowledge than men, and on a number of measures there were significant differences between these groups.

CONCLUSIONS

Poor knowledge about the timing, accessibility, action and side effects of EC may act as a barrier to its use in the event of unprotected sexual intercourse. Although EC has been available in Australia as a Schedule 3 medication since 2004, its availability from pharmacies is not well known, nor is access from other primary health care providers.

IMPLICATIONS

The lack of knowledge about EC may lead to its underutilisation and underlines the need for future educational strategies about EC as well as the need for health professionals who provide contraceptive services to discuss EC with clients. Health promotion campaigns which are both general as well as gender-specific may improve overall community knowledge about this method of contraception.

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.

Comparison of vaginal and oral administration of emergency contraception

OBJECTIVE

To compare the physiologic effects of vaginally and orally administered emergency contraception.

DESIGN

Prospective, open-label, crossover study.

SETTING

University research center.

PATIENT(S)

Nine regularly menstruating volunteers.

INTERVENTION(S)

Five subjects received 1,000 microg of levonorgestrel with 200 microg of ethinyl E2 (twice the standard Yuzpe regimen dose) vaginally, and the standard Yuzpe regimen dose orally 1 week later. Four subjects received 1,500 microg of levonorgestrel (twice the standard Plan B regimen dose) vaginally and received the standard Plan B dose orally 1 week later. Serum samples were obtained at baseline and at frequent intervals after each dose.

MAIN OUTCOME MEASURE(S)

Serum gonadotropin, hepatic globulin, and androgen levels measured at baseline, at the time of peak levonorgestrel, and 24 hours later.

RESULT(S)

Gonadotropin, hepatic globulin, and androgen levels were suppressed to a similar degree among the four regimens, with a return to baseline levels after 24 hours.

CONCLUSION(S)

We conclude that high doses of levonorgestrel found in emergency contraception regimens lead to a transient direct suppression of gonadotropin, hepatic globulin, and androgen levels. This effect is similar after vaginal and oral administration of emergency contraception. Therefore, the vaginal route of administration of emergency contraception regimens may be as efficacious as the oral route.

Changes in young women's awareness, attitudes, and perceived barriers to using emergency contraception

BACKGROUND

In a 1996 survey, most young women ages 13-20 years from an urban, hospital-based clinic and a drug treatment center had inadequate awareness of emergency contraception (EC), and perceived several barriers to its use. Since that time, the FDA has approved two products for EC, media coverage has increased, and physicians have provided more counseling about EC.

PURPOSE

The purpose of this study is to compare the awareness, attitudes, and perceived barriers to using EC among a sample of young women from 1996 with a different sample of women from 2002.

METHODS

We recruited 139 young women (mean age 16.7 +/- 1.8 yrs) from the same adolescent clinic and drug treatment center as the 1996 sample. They had similar demographic characteristics, with the majority (63%) being African-American or multi-ethnic; 85% had ever been sexually active. They were interviewed using a questionnaire about their sexual and contraceptive history as well as their knowledge of and experience with EC. They then watched a 4(1/2) minute video and received a 5-minute didactic review of EC. Following the educational intervention, participants' knowledge, attitudes, and perceived barriers to using EC were assessed. The questionnaire used to guide the interviews was nearly identical to that used in 1996.

RESULTS

Between 1996 and 2002, the percentage of participants reporting that they had ever heard of EC grew (44% vs. 73%, P < 0.001), as well as the percentage reporting that they had ever used EC (4% vs. 13%, P = 0.02). Of those participants who had ever heard of EC, fewer 1996 participants knew where to obtain it compared to 2002 participants (78% vs. 95%, P = 0.002) and fewer 1996 participants knew the correct time limits for use (20% vs. 51%, P < 0.001). The above data were collected prior to a didactic review session about EC. After receiving information about EC, the percentage of participants reporting a positive attitude toward EC grew between 1996 and 2002 (72% vs. 96%, P < 0.001). Young women also had fewer concerns about safety and side effects in 2002. The 1996 participants were more likely to report barriers to using EC compared to the 2002 participants. In 1996, EC side effects and impact on fertility were the most commonly perceived barriers to EC use. However, in 2002 the frequency of all reported barriers decreased and cost had become the number one perceived barrier.

CONCLUSION

Since 1996, young women at an urban hospital-based adolescent clinic and drug treatment center increased their awareness, use, and positive attitudes towards EC, as well as decreased their perceived barriers to using EC. Educational interventions that focus on improving knowledge among younger adolescents, specifically about correct time limits and identifying ways to find affordable EC, will address the most common knowledge deficits and perceived barriers to EC use among adolescents.

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--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.

Effects of the Yuzpe regimen, given during the follicular phase, on ovarian function

This study was conducted to assess to what extent the Yuzpe regimen, or half the dose, given in the follicular phase, prevents ovulation during the ensuing 5 days. Sixty women were divided into six groups. All groups received placebo in one cycle and drug in another, in a randomized order. Groups differed by the dose and size of the leading follicle at the time of treatment (12-14, 15-17, or 18-20 mm). Ovulation was absent during the ensuing 5 days in 13 of 20 participants (65%) and in 8 of 20 participants (40%) who received the full and the half dose, respectively, when follicles were 12-17 mm. No ovulation occurred, within the critical period, in 7 of 39 placebo cycles (18%). When follicles were 18-20 mm, treatment did not prevent ovulation. In most drug-treated cycles, plasma gonadotropin and sex steroid levels were significantly depressed within the 5-day period, even when follicular rupture occurred within that period. In conclusion, the Yuzpe regimen can suppress or postpone ovulation to an extent that exceeds the fertile life of spermatozoa. Lack of ovulation within the critical period and dysfunction of the ovulatory process probably account for the contraceptive effect of this method in most cases. The present data do not warrant the use of half the dose of the Yuzpe regimen.

Hormonal emergency contraception

In the 1960s, high-dose estrogen was identified as a highly effective emergency contraceptive but was associated with a high frequency of nausea and vomiting. The combination of low-dose estrogen and a progestin (the Yuzpe regimen) is highly effective and much better tolerated. Recently, a progestin-only regimen containing levonorgestrel was found to be more effective than the Yuzpe regimen and caused significantly less nausea and vomiting. Danazol, an antigonadotropin, is well tolerated but has questionable efficacy Mifepristone has several pharmacologic actions that make it highly effective with an adverse-effect profile similar to that of the Yuzpe regimen. Progress has been made in the last 3 years toward increasing the number of emergency contraceptives that are accessible to women in the United States, and several highly effective options are available. The most effective and well-tolerated regimen available is levonorgestrel. However, the barriers to access and low patient and provider awareness limit the impact of emergency contraception on the rate of unintended pregnancies.

On the mechanisms of action of short-term levonorgestrel administration in emergency contraception

The effects of short-term administration of levonorgestrel (LNG) at different stages of the ovarian cycle on the pituitary-ovarian axis, corpus luteum function, and endometrium were investigated. Forty-five surgically sterilized women were studied during two menstrual cycles. In the second cycle, each women received two doses of 0.75 mg LNG taken 12 h apart on day 10 of the cycle (Group A), at the time of serum luteinizing hormone (LH) surge (Group B), 48 h after positive detection of urinary LH (Group C), or late follicular phase (Group D). In both cycles, transvaginal ultrasound and serum LH were performed from the detection of urinary LH until ovulation. Serum estradiol (E2) and progesterone (P(4)) were measured during the complete luteal phase. In addition, an endometrial biopsy was taken at day LH + 9. Eighty percent of participants in Group A were anovulatory, the remaining (three participants) presented significant shortness of the luteal phase with notably lower luteal P4 serum concentrations. In Groups B and C, no significant differences on either cycle length or luteal P4 and E2 serum concentrations were observed between the untreated and treated cycles. Participants in Group D had normal cycle length but significantly lower luteal P4 serum concentrations. Endometrial histology was normal in all ovulatory-treated cycles. It is suggested that interference of LNG with the mechanisms initiating the LH preovulatory surge depends on the stage of follicle development. Thus, anovulation results from disrupting the normal development and/or the hormonal activity of the growing follicle only when LNG is given preovulatory. In addition, peri- and post-ovulatory administration of LNG did not impair corpus luteum function or endometrial morphology.

The emergency contraception collaborative prescribing experience in Washington State

OBJECTIVE

To describe how prescribers and pharmacists view the Emergency Contraceptive Pills (ECP) program, and to evaluate pharmacists' performance through the use of a consumer survey.

DESIGN

Self-administered provider satisfaction surveys were mailed 6 months after the program's inception. Consumer satisfaction surveys were distributed at the point of ECP service for return by mail.

SETTING

The program encouraged pharmacists and prescribers in western Washington to enter into collaborative prescribing agreements, increasing consumers' access to ECP.

PATIENTS OR OTHER PARTICIPANTS

Pharmacists who had attended ECP training sessions, prescribers who had authorized pharmacists to prescribe ECP, and women who had been prescribed ECP by pharmacists.

MAIN OUTCOME MEASURES

Providers' reasons for participating, attitudes toward the ECP program, and experiences with ECP as a result of the program; feedback from women receiving ECP from pharmacists.

RESULTS

309 pharmacist surveys and 55 prescriber surveys were sent, of which 159 (51%) and 27 (49%), respectively, were returned. Meeting patient needs and having a professional responsibility to participate were commonly reported reasons for ECP program involvement. Both pharmacists and prescribers (92%) reported being "satisfied" or "very satisfied" with their prescribing agreements. On the 470 consumer surveys returned out of 7,000 distributed (6.5%), pharmacists were rated highly satisfactory for their interactions with patients and the quality of information about ECP use given, but less satisfactory for information about adverse effects, recognition and follow-up of ECP failure, and regular contraceptive methods.

CONCLUSION

All participants expressed satisfaction with the ECP program. This example should support the initiation of similar programs in other states.

The mechanism of action of hormonal contraceptives and intrauterine contraceptive devices

Modern hormonal contraceptives and intrauterine contraceptive devices have multiple biologic effects. Some of them may be the primary mechanism of contraceptive action, whereas others are secondary. For combined oral contraceptives and progestin-only methods, the main mechanisms are ovulation inhibition and changes in the cervical mucus that inhibit sperm penetration. The hormonal methods, particularly the low-dose progestin-only products and emergency contraceptive pills, have effects on the endometrium that, theoretically, could affect implantation. However, no scientific evidence indicates that prevention of implantation actually results from the use of these methods. Once pregnancy begins, none of these methods has an abortifacient action. The precise mechanism of intrauterine contraceptive devices is unclear. Current evidence indicates they exert their primary effect before fertilization, reducing the opportunity of sperm to fertilize an ovum.

Effect of norgestrel on development of mouse pre-embryos

The effect of synthetic progestins found in oral contraceptives has potential implications for developing embryos in women who receive oral contraceptives during early pregnancy. We assessed the effect of the progestin norgestrel on the developing pre-embryo. B3C6F1 mice were given 5 IU PMSG followed by 5 IU hCG 48h later. Studies were performed on pre-embryos recovered and pooled at both 24h (Group A) and 48h (Group B) post hCG. At each time period, they were randomly assigned to control or norgestrel (4.0 ng/ml) treatment. In a third study, pre-embryos collected 24h post hCG were cultured in the absence or presence of 8.0, 80.0, or 800 ng/ml norgestrel. Cultures were performed in Ham's F-10 media with 10% fetal calf serum at 37 degrees C in an atmosphere of 5% CO2, 5% O2 and 90% N2 with 15-30 embryos per 1 ml of culture fluid. At 24h, 48h and 72h post recovery, cultures were viewed, the appearance of embryos noted, and number of blastomeres recorded. Compared to control groups, analysis demonstrated no significant difference in the rate of development of control and norgestrel pre-embryos in any group at any time period (24h, 48h, or 72h post recovery). We conclude that norgestrel at the dose tested has no acute adverse morphological effects on development of mouse pre-embryos. This observation has potential clinical implications with regard to inadvertent use of norgestrel-containing oral contraceptives during early days of pregnancy, as well as consideration of the mechanism of action of norgestrel-containing "morning after" pills.

A possible mechanism of action of danazol and an ethinylestradiol/norgestrel combination used as postcoital contraceptive agents

Twenty-seven women requesting postcoital contraception were randomly allocated to take an ethinylestradiol/dl-norgestrel combination or danazol. Urine specimens were assayed for luteinising hormone (LH) and pregnanediol-3-glucuronide (P3G) levels from the day of the postcoital treatment to the next period. In addition, the urine samples of these recruits and 12 additional women were assayed for the Beta-subunit of human chorionic gonadotropin (B-hCG). A consistent pattern of alteration in urinary steroids was lacking, indicating a heterogeneous effect on ovarian function. There was no evidence of early pregnancy in successfully treated cases. We suggest that the main mechanism of action of these drugs is at the endometrial level.

Serum gonadotropin and ovarian steroid levels in women during administration of a norethindrone-ethinylestradiol triphasic oral contraceptive

We studied the inhibitory effect of a triphasic oral contraceptive (OC) regimen on the pituitary and ovarian function in 29 normal, healthy women. ORTHO* 7/7/7 Tablets contain a constant low dose of ethinylestradiol (EE) and a step-wise increasing level of norethindrone (NE). The pills for the first, middle and last weeks of the 21-day regimen contained, respectively, 0.5, 0.75, and 1.00 mg NE, and all contained 0.035 mg EE. The subjects were divided into 3 groups on the basis of their histories of OC use. Ten had not taken an OC in the previous 2 months, 10 were switched to this study from a fixed-dosage combination OC containing 0.050 mg estrogen, and 9 had been taking ORTHO 7/7/7 Tablets for 5 or more cycles. Serum levels of FSH, LH, estradiol and progesterone were measured and statistically compared with those from 5 normal, untreated women. The results from all study cycles showed that the four hormone profiles were significantly suppressed as compared to the normal patterns. Thus, one mode of action of this new triphasic OC is to inhibit ovulation by suppression of pituitary-ovarian function. This OC treatment appeared to be equally effective among women with varying prior histories of OC therapy.