Mechanism of action of hormonal preparations used for emergency contraception: a review of the literature

Emergency contraception in the emergency department

BACKGROUND

On June 24, 2022, the Supreme Court overturned Roe v. Wade, which will limit legal abortion in many areas of the U.S., making the need for effective emergency contraception even more critical.

METHODS

This narrative review focuses on the approach to providing safe and effective emergency contraception in the emergency department (ED) with a focus on agents that are used in the U. S.; however, many of the agents discussed are also available and utilized in other countries.

RESULTS

Emergency contraception methods included in this review are, ulipristal, levonorgestrel, combined oral contraceptive pills, and copper intrauterine devices (IUDs).

CONCLUSION

The efficacy of products used for emergency contraception depend on patient and temporal factors. Emergency physicians must have an understanding of the optimal use of these agents to prevent unwanted pregnancy, particularly in the setting of restricted abortion access.

Ectopic Pregnancy Following Levonorgestrel Emergency Contraception: Report of Two Cases

Abstract Ectopic pregnancy (EP) is likely to occur as an unwanted complication after unprotected intercourse in spite of levonorgestrel emergency contraception (LNG-EC).   Its incidence has been increasing recently. We present 2 cases of tubal EP  after the oral use of levonorgestrel, treated by  laparoscopy.The first unruptured EP with unclear ultrasound findings, because of   uterine ventrofixation  after the caesarean section (CS) . The second case is a ruptured EP after LNG –EC   on day 24 of the period  with mild  haemoperitoneum with severe peritoneal irritation. The fundamental question is whether levonorgestrel participates in the etiology of EP. The etiology of EP involves many factors. Levonorgestrel mechanisms of action give us grounds to believe theoretically that it increases the risk of EP and participates as an etiological factor.  

Case of rupture ectopic pregnancy with emergency contraception levonorgestrel 0.075 mg in a lactating woman

Levonorgestrel emergency contraception (LNG-EC) tends to make uterus unfavorable for implantation but does not prevent embryo implantation. Emergency contraceptives pills should be used with caution among lactating women who at the same time should be monitored closely for ectopic pregnancy.

The effects of levonorgestrel on FSH-stimulated primary rat granulosa cell cultures through gene expression profiling are associated to hormone and folliculogenesis processes

Levonorgestrel (LNG), a synthetic progestin, is used in emergency contraception (EC). The mechanism is preventing or delaying ovulation at the level of the hypothalamic pituitary unit; however, little knowledge exists on LNG effects at the ovary. The aim of this study was to identify the effects of LNG on FSH-induced 17β-estradiol (E₂) production, including LNG-mediated changes on global gene expression in rat granulosa cells (GC). Isolated GC from female Wistar rats were incubated in vitro in the presence or absence of human FSH and progestins. At the end of incubations, culture media and cells were collected for E₂ and mRNA quantitation. The results showed the ability of LNG to inhibit both hFSH-induced E₂ production and aromatase gene expression. Microarray analysis revealed that LNG treatment affects GC functionality particularly that related to folliculogenesis and steroid metabolism. These results may offer additional evidence for the mechanisms of action of LNG as EC.

Pharmacist Critique Was Ill-Informed

Pharmacists’ ability to exercise “professional right of conscience” in dispensing emergency contraception, as well as the professionalism of pharmacists, has fallen under attack recently by the media, by state governments, and even by other healthcare professionals in published commentaries. This editorial discusses the controversy surrounding emergency contraceptives, the right of pharmacists to refuse to fill prescriptions that they consider morally objectionable, and the responsibility of pharmacists to provide medications in a timely and professional manner. The professionalism of pharmacy is also examined in light of the expanded scope of practice in which pharmacists increasingly find themselves practicing.

A prospective, open-label, single arm, multicentre study to evaluate efficacy, safety and acceptability of pericoital oral contraception using levonorgestrel 1.5 mg

STUDY QUESTION

Will the use of levonorgestrel (LNG) 1.5 mg taken at each day of coitus by women who have relatively infrequent sex be an efficacious, safe and acceptable contraceptive method?

SUMMARY ANSWER

Typical use of LNG 1.5 mg taken pericoitally, before or within 24 h of sexual intercourse, provides contraceptive efficacy of up to 11.0 pregnancies per 100 women-years (W-Y) in the primary evaluable population and 7.1 pregnancies per 100 W-Y in the evaluable population.

WHAT IS KNOWN ALREADY

LNG 1.5 mg is an effective emergency contraception following unprotected intercourse. Some users take it repeatedly, as their means of regular contraception.

STUDY DESIGN, SIZE, DURATION

This was a prospective, open-label, single-arm, multicentre Phase III trial study with women who have infrequent coitus (on up to 6 days a month). Each woman had a follow-up visit at 2.5, 4.5 and 6.5 months after admission or until pregnancy occurs if sooner, or she decided to interrupt participation. The study was conducted between 10 January 2012 and 15 November 2014.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A total of 330 healthy fertile women aged 18-45 years at risk of pregnancy who reported sexual intercourse on up to 6 days a month, were recruited from four university centres located in Bangkok, Thailand; Campinas, Brazil; Singapore and Szeged, Hungary to use LNG 1.5 mg pericoitally (24 h before or after coitus) as their primary method of contraception. The participants were instructed to take one tablet every day she had sex, without taking more than one tablet in any 24-h period, and to maintain a paper diary for recording date and time for every coital act and ingestion of the study tablet, use of other contraceptive methods and vaginal bleeding patterns. Anaemia was assessed by haemoglobin evaluation. Pregnancy tests were performed monthly and pregnancies occurring during product use were assessed by ultrasound. At the 2.5-month and final visit at 6.5 months, acceptability questions were administered.

MAIN RESULTS AND THE ROLE OF CHANCE

There were 321 women included in the evaluable population (which includes all eligible women enrolled), with 141.9 woman-years (W-Y) of observation and with a rate (95% confidence interval [CI]) of 7.1 (3.8; 13.1) pregnancies per 100 W-Y of typical use (which reflects use of the study drug as main contraceptive method, but also includes possible use of other contraceptives from admission to end of study) and 7.5 (4.0; 13.9) pregnancies per 100 W-Y of sole use. In the primary evaluable population (which includes only eligible enrolled women <35 years old), the rate was 10.3 (5.4; 19.9) pregnancies per 100 W-Y of typical use, and 11.0 (5.7; 13.1) pregnancies per 100 W-Y of sole use. There were three reported severe adverse events and 102 other mild adverse events (most common were headache, nausea, abdominal and pelvic pain), with high recovery rate. The vaginal bleeding patterns showed a slight decrease in volume of bleeding and the number of bleeding-free days increased over time. There was only one case of severe anaemia, found at the final visit (0.4%). The method was considered acceptable, as over 90% of participants would choose to use it in the future or would recommend it to others.

LIMITATIONS, REASONS FOR CAUTION

This was a single-arm study with small sample size, without a control group, designed as a proof of concept study to explore the feasibility of this type of contraception.

WIDER IMPLICATIONS OF THE FINDINGS

A larger clinical study evaluating pericoital contraception with LNG is feasible and our data show that this method would be acceptable to many women.

STUDY FUNDING/COMPETING INTERESTS

This study received partial financial support from the UNDP/UNFPA/UNICEF/WHO/World Bank Special Programme of Research, Development and Research Training in Human Reproduction (HRP), Department of Reproductive Health and Research (RHR) and the World Health Organization. Gynuity and the Bill and Melinda Gates Foundation (BMGF) provided financial support for project monitoring. HRA Pharma donated the LNG product. N.K. was the initial project manager when she was with WHO/HRP and was employed by HRA Pharma, which distributes LNG for emergency contraception. The other authors declare no conflicts of interest.

TRIAL REGISTRATION NUMBER

This study was registered on ANZCTR, Trial ID ACTRN12611001037998.

TRIAL REGISTRATION DATE

4 October 2011.

DATE OF FIRST PATIENT'S ENROLMENT

10 January 2012.

Does levonorgestrel emergency contraceptive have a post-fertilization effect? A review of its mechanism of action

BACKGROUND

Recent studies have identified that levonorgestrel administered orally in emergency contraception (LNG-EC) is only efficacious when taken before ovulation. However, the drug does not consistently prevent follicular rupture or impair sperm function.

OBJECTIVE

The present systematic review is performed to analyze and more precisely define the extent to which pre-fertilization mechanisms of action may explain the drug's efficacy in pregnancy avoidance. We also examine the available evidence to determine if pre-ovulatory drug administration may be associated with post-fertilization effects.

CONCLUSION

The mechanism of action of LNG-EC is reviewed. The drug has no ability to alter sperm function at doses used in vivo and has limited ability to suppress ovulation. Our analysis estimates that the drug's ovulatory inhibition potential could prevent less than 15 percent of potential conceptions, thus making a pre-fertilization mechanism of action significantly less likely than previously thought. Luteal effects (such as decreased progesterone, altered glycodelin levels, and shortened luteal phase) present in the literature may suggest a pre-ovulatory induced post-fertilization drug effect.

LAY SUMMARY

Plan B is the most widely used emergency contraceptive available. It is important for patients and physicians to clearly understand the drug's mechanism of action (MOA). The drug was originally thought to work by preventing fertilization. Recent research has cast doubt on this. Our review of the research suggests that it could act in a pre-fertilization capacity, and we estimate that it could prevent ovulation in only 15 percent or less of cases. The drug has no ability to alter sperm function and limited ability to suppress ovulation. Further, data suggest that when administered pre-ovulation, it may have a post-fertilization MOA.

#ec: Findings and implications from a quantitative content analysis of tweets about emergency contraception

Twitter, a popular social media, helps users around the world quickly share and receive information. The way in which Twitter frames health issues - especially controversial issues like emergency contraception (EC) - can influence public opinion. The current study analyzed all English-language EC-related tweets from March 2011 (n = 3535). Variables measured user characteristics (e.g. gender), content (e.g. news, humor), Twitter-specific strategy (e.g. retweet), and certain time periods (e.g. weekends). The analysis applied chi-square and regression analyses to the variables. Tweets most frequently focused on content related to news (27.27%), accessing EC (27.27%), and humor (25.63%). Among tweets that were shared, however, the most common content included humor, followed by personal/vicarious experience. Although only 5.54% of shared tweets mentioned promiscuity, this content category had the strongest odds for being shared (OR = 1.51; p = 0.031). The tweet content with lowest odds of being shared were side effects (OR = 0.24; p < 0.001), drug safety (OR = 0.44; p < 0.001), and news (OR = 0.44; p < 0.001). Tweets with the greatest odds of having been sent on a weekend sought advice (OR = 1.94; p = 0.012), addressed personal or vicarious experience (OR = 1.91; p < 0.001), or contained humor (OR = 1.56; p < 0.001). Similar patterns occurred in tweets sent around St. Patrick's Day. Only a few differences were found in the ways in which male and female individuals discussed EC on Twitter. In particular, when compared to males, females mentioned birth control (p = 0.002), EC side effects (p = 0.024), and issues related to responsibility (p = 0.003) more often than expected. Study findings offer timely and practical suggestions for public health professionals wanting to communicate about EC via Twitter.

Emergency contraception: Sources of information and perceptions of access among young adults

Emergency contraception (EC) can prevent pregnancy for up to 5 days after unprotected sex. Although EC has become increasingly available, little is known about perceptions of young adults regarding access to EC or whether information sources about EC relate to perceived access among young adults. Over a 1-week period in November 2013, a self-report survey was administered to 352 college students (67% women) at the student union of a large, public university in the southeastern United States. The survey assessed three aspects of EC: perceived access, information sources, and prior use. Twenty-one percent of participants had used EC. Participants reported relatively high perceptions of access to EC, with females reporting higher perceptions of access than males. Prior to the study, 7.4% of students had never heard of EC; the remaining students had heard of EC from an average of four sources. Among women, hearing of EC from media, interpersonal, or health education sources was significantly associated with greater perceived access (ps < .05). Among men, no specific information sources were associated with perceived access (ps > .10). Future EC awareness efforts for women should leverage all three of these sources, while future research should examine specific sources to focus on the content, quality, and frequency of messages.

Practice Bulletin No. 152: Emergency Contraception

Emergency contraception, also known as postcoital contraception, is therapy used to prevent pregnancy after an unprotected or inadequately protected act of sexual intercourse. Common indications for emergency contraception include contraceptive failure (eg, condom breakage or missed doses of oral contraceptives) and failure to use any form of contraception (). Although oral emergency contraception was first described in the medical literature in the 1960s, the U.S. Food and Drug Administration (FDA) approved the first dedicated product for emergency contraception in 1998. Since then, several new products have been introduced. Methods of emergency contraception include oral administration of combined estrogen-progestin, progestin only, or selective progesterone receptor modulators and insertion of a copper intrauterine device (IUD). Many women are unaware of the existence of emergency contraception, misunderstand its use and safety, or do not use it when a need arises (). The purpose of this Practice Bulletin is to review the evidence for the efficacy and safety of available methods of emergency contraception and to increase awareness of these methods among obstetrician-gynecologists and other gynecologic providers.

Emergency contraception: What is new?

Unintended pregnancy rates remain high throughout the World and increase the risk of poor maternal and infant outcomes. Most of unintended pregnancies occur in women who were not using contraception or who became pregnant despite the reported use of contraception. Women who have had recent unprotected intercourse including those who have had another form of contraception fail are potential candidates for this intervention. Currently used emergency contraceptive methods are pills that contain combined estrogen-progesterone, only progestin, antiprogestins and copper intrauterine devices. The most common form of this type of contraception is oral progestin-only pills (levonorgestrel). The most effective method is copper intrauterine devices followed by anti-progestins and oral progestin-only pills. The major pathogenesis of oral emergency contraceptives is the prevention or delay of ovulation. Although conception is possible on only a few days of the cycle, emergency contraception is offered when indicated without regard to the timing of the menstrual cycle because of uncertainty in the timing of the ovulation. Levonorgestrel and E/P regimes are most effective as soon as possible after unprotected sexual intercourse. A linear relationship has been shown between effectiveness and the time of dose. The effectiveness continues for 120 h, but it is recommended to be used within 72 h after intercourse. Intrauterine devices may prevent pregnancy when 5 d after ovulation.

The expression of thyroid hormone receptors (THR) is regulated by the progesterone receptor system in first trimester placental tissue and in BeWo cells in vitro

BACKGROUND

Thyroid hormones are essential for the maintenance of pregnancy and a deficiency in maternal thyroid hormones has been associated with early pregnancy losses. The aim of this study was a systematic investigation of the influence of mifepristone (RU 486) on the expression of the thyroid hormone receptor (THR) isoforms THRα1, THRα2, THRβ1 and THRβ2 on protein and mRNA-level.

METHODS

Samples of placental tissue were obtained from patients with mifepristone induced termination of pregnancy (n=13) or mechanical induced termination of normal pregnancy (n=20), each from the 4th to 13th week of pregnancy. Expression of THRα1, THRα2, THRβ1 and THRβ2 was analysed on protein level by immunohistochemistry and on mRNA level by real time RT-PCR (TaqMan). The influence of progesterone on THR gene expression was analysed in the trophoblast tumour cell line BeWo by real time RT-PCR (TaqMan).

RESULTS

Nuclear expression of THRα1, THRα2 and THRβ1 is downregulated on protein level in mifepristone (RU 486) treated villous trophoblast tissue. In decidual tissue, we found a significant downregulation only for THRα1 in mifepristone treated tissue. On mRNA level, we also found a significantly reduced expression of THRA but no significant downregulation for THRB in placental tissue. The gene THRA encodes the isoform THRα and the gene THRB encodes the isoform THRβ. The majority of cells expressing the thyroid hormone receptors in the decidua are decidual stromal cells. In addition, in vitro experiments with trophoblast tumour cells showed that progesterone significantly induced THRA but not THRB expression.

CONCLUSIONS

Termination of pregnancy with mifepristone (RU 486) leads to a downregulation of THRα1, THRα2 and THRβ1 in villous trophoblasts and in addition to a decreased expression of THRA in placental tissue. Decreased expression of THRα1 induced by RU486 could also be found in the decidua. Therefore inhibition of the progesterone receptor may be responsible for this downregulation. This assumption is supported by the finding, that stimulation of the progesterone receptor by progesterone itself up-regulated THRA in trophoblast cells in vitro.

Adolescent Girls and Abortion

Abortion is an extremely common procedure in the United States, with approximately 2% of women having an abortion before age 19 years. Although most pediatricians do not provide abortions, many will care for a young woman who is either considering an abortion or has already had one; therefore, the pediatrician should be able to provide accurate and appropriate counseling about this option. To provide the best care for adolescent patients considering abortion, pediatricians must be knowledgeable of aspects of abortion that are universal to all women and have an understanding of considerations specific to the adolescent patient. The purpose of this article is to (1) review recent statistics about teenagers and abortion, (2) explain the different types of abortion available to teenagers who desire to terminate an unwanted pregnancy, (3) discuss aspects of abortion unique to the adolescent population, such as insurance coverage and parental involvement laws, and (4) address common misconceptions about abortion. [Pediatr Ann. 2015;44(9):384-385,388,390,392.].

Mifepristone 5 mg versus 10 mg for emergency contraception: double-blind randomized clinical trial

Purpose

To estimate the efficacy and safety of 5 mg and 10 mg mifepristone for emergency contraception up to 144 hours after unprotected coitus.

Methods

This double-blind randomized clinical trial was carried out at Eusebio Hernandez Hospital (Havana, Cuba). A total of 2,418 women who requested emergency contraception after unprotected coitus received either 5 mg or 10 mg mifepristone. The variables for assessing efficacy were the pregnancies that occurred and the fraction of pregnancies that were prevented. Other variables assessed were the side effects of mifepristone, vaginal bleeding, and changes in the date of the following menstruation.

Results

There were 15/1,206 (1.2%) and 9/1,212 (0.7%) pregnancies in the 5 mg and 10 mg group, respectively (P=0.107). There were 88% and 93% prevented pregnancies in the 5 mg and un ≥7 days was experienced by 4.9% and 11.0% of subjects in the 5 mg and 10 mg group, respectively (P=0.001). There was a significant high failure rate for women weighing >75 kg in the 5 mg group.

Conclusion

It would be advisable to use the 10 mg dose of mifepristone for emergency contraception as there was a trend suggesting that the failure rate of the larger dose was lower.

Physical and mental development of children after levonorgestrel emergency contraception exposure: a follow-up prospective cohort study

Levonorgestrel (LNG), a dedicated emergency contraception (EC) product, has been available over-the-counter in China for more than 14 yr. Although LNG-EC is considered to have no effects on the developing fetus if the contraceptive fails and pregnancy occurs, there have been a few studies specifically examining this issue. The purpose of this study was to compare the physical and mental development of children born after LNG-EC failure with that of a cohort of children born to mothers with no history of exposure to LNG or any teratogenic substances. A group of 195 children who were exposed to LNG-EC during their mothers' conception cycle (study group) were matched to a group of 214 children without exposure to LNG (control group). The physical and mental development of the children were evaluated and compared over a 2-yr period. There were four congenital malformations in the study group and three in the control group (2.1% vs. 1.4%, respectively, P > 0.05). Over the 2-yr follow-up period, there were no statistically significant differences between the two groups with respect to children's weight, height, head circumference, and intelligence scores, and the values of all parameters of both groups were similar to those of the national standards. In summary, LNG-EC has no effect on the physical growth, mental development, or occurrence of birth defects in children born from pregnancies in which EC failed.

A systematic review of effectiveness and safety of different regimens of levonorgestrel oral tablets for emergency contraception

BACKGROUND

Unintended pregnancy is a complex phenomenon which raise to take an emergency decision. Low contraceptive prevalence and high user failure rates are the leading causes of this unexpected situation. High user failure rates suggest the vital role of emergency contraception to prevent unplanned pregnancy. Levonorgestrel - a commonly used progestin for emergency contraception. However, little is known about its pharmacokinetics and optimal dose for use. Hence, there is a need to conduct a systematic review of the available evidences.

METHODS

Randomized, double-blind trials were sought, evaluating healthy women with regular menstrual cycles, who requested emergency contraception within 72 h of unprotected coitus, to one of three regimens: 1.5 mg single dose levonorgestrel, two doses of 0.75 mg levonorgestrel given 12 h apart or two doses of 0.75 mg levonorgestrel given 24 h apart. The primary outcome was unintended pregnancy; other outcomes were side-effects and timing of next menstruation.

RESULTS

Every trial under consideration successfully established the contraceptive effectiveness of levonorgestrel for preventing unintended pregnancy. Moreover, a single dose of levonorgestrel 1.5 mg for emergency contraception supports its safety and efficacy profile. If two doses of levonorgestrel 0.75 mg are intended for administration, the second dose can positively be taken 12-24 h after the first dose without compromising its contraceptive efficacy. The main side effect was frequent menstrual irregularities. No serious adverse events were reported.

CONCLUSIONS

The review shows that, emergency contraceptive regimen of single-dose levonorgestrel is not inferior in efficacy to the two-dose regimen. All the regimens studied were very efficacious for emergency contraception and prevented a high proportion of pregnancies if taken within 72 h of unprotected coitus. Single levonorgestrel dose (1.5 mg) can substitute two 0.75 mg doses 12 or 24 h apart. With either regimen, the earlier the treatment is given, the more effective it seems to be.

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.

Update on emergency contraception

Emergency contraception (EC) is any method used after sexual intercourse to prevent pregnancy. This article provides an overview of the history of EC methods and describes the current availability of oral and intrauterine EC. Oral forms include the Yuzpe regimen (combining ethinyl estradiol and levonorgestrel), levonorgestrel-only pills, and ulipristal acetate, which is a new emergency contraceptive drug recently approved by the US Food and Drug Administration. The copper T-380A intrauterine device can also be used for EC. Information about dosing, timing, access, and other considerations in the provision of EC is covered. Clinicians should be aware of all available options in order to counsel women in need of EC appropriately.

Emergency contraception: clinical outcomes

Emergency contraception (EC) is widely used to prevent unwanted pregnancy. This review considers the safety and efficacy of three commonly used methods -- levonorgestrel (LNG-EC), ulipristal acetate (UPA) and the copper intrauterine device. All are extremely safe, and side effects are minimal. Concerns about increased risks of ectopic pregnancy after EC use have proved unfounded, and possible teratogenic effects seem unlikely. Although the true effectiveness of EC is impossible to estimate, recent research suggests that LNG-EC prevents around 50% of expected pregnancies in women using the method within 72 h of intercourse, whereas UPA appeared to prevent almost two thirds of pregnancies. Emergency intrauterine device insertion probably prevents over 95% of pregnancies. However, although improved accessibility of EC has clearly led to increased use, it does not appear to have had any public health benefit in reducing unintended pregnancy rates. Most of the data on sexual behavior following improved access to EC do not show any detrimental effect on subsequent use of other more effective methods of contraception or on the incidence of unintended pregnancy or sexually transmitted infection. However, unless these other methods of contraception are also made easily available from pharmacies, improved access to EC risks unlinking its use with use of subsequent ongoing contraception.

Emergency contraception

OBJECTIVE

To review current knowledge about emergency contraception (EC), including available options, their modes of action, efficacy, safety, and the effective provision of EC within a practice setting.

OPTIONS

The combined estradiol-levonorgestrel (Yuzpe regimen) and the levonorgestrel-only regimen, as well as post-coital use of copper intrauterine devices, are reviewed.

OUTCOMES

Efficacy in terms of reduction in risk of pregnancy, safety, and side effects of methods for EC and the effect of the means of access to EC on its appropriate use and the use of consistent contraception.

EVIDENCE

Studies published in English between January 1998 and March 2010 were retrieved though searches of Medline and the Cochrane Database, using appropriate key words (emergency contraception, post-coital contraception, emergency contraceptive pills, post-coital copper IUD). Clinical guidelines and position papers developed by health or family planning organizations were also reviewed.

VALUES

The studies reviewed were classified according to criteria described by the Canadian Task Force on Preventive Health Care, and the recommendations for practice were ranked according to this classification (Table 1).

BENEFITS, HARMS, AND COSTS

These guidelines are intended to help reduce unintended pregnancies by increasing awareness and appropriate use of EC.

SPONSOR

The Society of Obstetricians and Gynaecologists of Canada. Summary Statements 1. Hormonal emergency contraception may be effective if used up to 5 days after unprotected intercourse. (II-2) 2. The earlier hormonal emergency contraception is used, the more effective it is. (II-2) 3. A copper IUD can be effective emergency contraception if used within 7 days after intercourse. (II-2) 4. Levonorgestrel emergency contraception regimens are more effective and cause fewer side effects than the Yuzpe regimen. (I) 5. Levonorgestrel emergency contraception single dose (1.5 mg) and the 2-dose levonorgestrel regimen (0.75 mg 12 hours apart) have similar efficacy with no difference in side effects. (I) 6. Of the hormonal emergency contraception regimens available in Canada, levonorgestrel-only is the drug of choice. (I) 7. A pregnancy that results from failure of emergency contraception need not be terminated (I) Recommendations 1. Emergency contraception should be used as soon as possible after unprotected sexual intercourse. (II-2A) 2. Emergency contraception should be offered to women if unprotected intercourse has occurred within the time it is known to be effective (5 days for hormonal methods and up to 7 days for a copper IUD). (II-2B) 3. Women should be evaluated for pregnancy if menses have not begun within 21 days following emergency contraception treatment. (III-A) 4. During physician visits for periodic health examinations or reproductive health concerns, any woman in the reproductive age group who has not been sterilized may be counselled about emergency contraception in advance with detailed information about how and when to use it. (III-C).

Obstetrician-gynecologists' beliefs about when pregnancy begins

OBJECTIVE

The purpose of this study was to assess obstetrician-gynecologists' regarding their beliefs about when pregnancy begins and to measure characteristics that are associated with believing that pregnancy begins at implantation rather than at conception.

STUDY DESIGN

We mailed a questionnaire to a stratified, random sample of 1800 practicing obstetrician-gynecologists in the United States. The outcome of interest was obstetrician-gynecologists' views of when pregnancy begins. Response options were (1) at conception, (2) at implantation of the embryo, and (3) not sure. Primary predictors were religious affiliation, the importance of religion, and a moral objection to abortion.

RESULTS

The response rate was 66% (1154/1760 physicians). One-half of US obstetrician-gynecologists (57%) believe pregnancy begins at conception. Fewer (28%) believe it begins at implantation, and 16% are not sure. In multivariable analysis, the consideration that religion is the most important thing in one's life (odds ratio, 0.5; 95% confidence interval, 0.2-0.9) and an objection to abortion (odds ratio, 0.4; 95% confidence interval, 0.2-0.9) were associated independently and inversely with believing that pregnancy begins at implantation.

CONCLUSION

Obstetrician-gynecologists' beliefs about when pregnancy begins appear to be shaped significantly by whether they object to abortion and by the importance of religion in their lives.

In vitro assessment of some sperm function following exposure to levonorgestrel in human fallopian tubes

BACKGROUND

The mechanism of action of levonorgestrel (LNG) as emergency contraception (EC) remains a subject of debate and its effect on sperm function has been only partially explained. The aim of this study was to assess whether LNG at a similar dose to those found in serum following oral intake for EC could affect spermatozoa when exposed to human fallopian tubes in vitro.

METHODS

Fifteen mini-laparotomies were performed, the side on which ovulation occurred was recorded, and both tubes were removed and perfused with a suspension containing 1 × 10(6) motile spermatozoa, with or without LNG. Following 4-hour incubation, the tubes were sectioned to separate the isthmus and the ampulla. Each segment was flushed and the material was evaluated to quantify the number of motile sperm, the number of spermatozoa adhering to the oviductal epithelium and the acrosome reaction (AR) rate.

RESULTS

The addition of LNG did not significantly alter the number of recovered motile spermatozoa either at the isthmus or at the ampulla, nor did it have any effect on the number of recovered spermatozoa adhered to the human tubal epithelium. Furthermore, LNG did not affect the AR rate. No significant differences were found even when the side on which ovulation occurred was taken into account.

CONCLUSIONS

In a similar dose to that observed in serum following oral intake for EC, LNG had no effect on the number of motile spermatozoa recovered from the human fallopian tubes in vitro, on their adhesion to the tubal epithelium, distribution or AR rate. The possible effect of LNG as EC on sperm function remains poorly understood.

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.

Misconceptions about missed conceptions: the meanings of emergency contraceptive pills use among young adult couples

Emergency contraceptive pills (ECP) are a safe and efficacious backup method of birth control. Despite widespread availability, ECP is underutilized by young women. While partner level of involvement has been shown to influence contraceptive behavior, there is a dearth of knowledge regarding any possible association between partner influence and ECP use. To better understand the reasons for the seemingly underuse of ECP, a grounded theory study was conducted to elucidate the relationship of couple dynamics and knowledge of, attitudes toward, and decision making regarding the use of ECP in coupled young adults. Consistent with contemporary constructivist grounded theory methods, several categories were identified including the meanings associated with ECP use. This article presents an elaboration of this particular finding. The meanings that participants ascribed to ECP use represented a continuum of value attributes regarding ethics, safety, efficacy, and responsibility.

How do levonorgestrel-only emergency contraceptive pills prevent pregnancy? Some considerations

Controversial opinions exist about the possible mechanisms throughout emergency contraception prevents pregnancy. Recently, the International Federation of Gynaecology and Obstetrics and the International Consortium for Emergency Contraception released a Joint Statement declaring that 'inhibition or delay of ovulation should be their primary and possibly only mechanism of action'. They still added that 'Review of the evidence suggests that LNG-ECPs cannot prevent implantation'. Concerning levonorgestrel-only emergency contraceptive pills effects on ovulation, the Statement based on seven reference papers which considered a total of only 142 patients, divided into still different subgroups. Basing on their same references we got quite different conclusions.

A nonhormonal model for emergency contraception: prostaglandin synthesis inhibitor effects on luteal function and lifespan, a pilot study

OBJECTIVES

The purpose of this study is to determine if the use of a specific prostaglandin endoperoxide-2 inhibitor will prevent luteal development in women.

STUDY DESIGN

Ovulatory reproductive-aged women not using or needing hormonal contraception were prospectively followed for three menstrual cycles. Women were randomized into two groups using a crossover design [Group 1: control cycle, placebo cycle, active drug (celecoxib 400 mg orally) cycle; Group 2: control cycle, celecoxib cycle, placebo cycle]. Study drug was dosed daily until the onset of the next menses. Demographics, menstrual cycle length and twice-weekly progesterone (P) levels during the placebo and active drug cycles were recorded. End points included the change in luteal phase P levels and menstrual cycle length (days) during active drug exposure.

RESULTS

A total of 11 women completed the study (Group 1, n=7; Group 2, n=4). No demographic differences were found between groups [age, race, body mass index (BMI), control cycle length]. A comparison of the control and active drug cycles for all participants demonstrated a trend toward a longer menstrual cycle with active drug exposure [control, 27.2 days (SD, 2.4); study drug, 28.5 days (SD, 2.5), p=.09]. Five women had a delay in the rise of their luteal phase P levels, two women had lower peak P levels and two women had no elevation of luteal phase P levels during active drug cycle as compared to placebo cycle.

CONCLUSION

Daily administration of a prostaglandin synthesis inhibitor may delay the timing of luteal events and, therefore, fertility in women. PTGS2 inhibitors may hold potential as an emergency contraceptive.

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.

Reasons for requesting emergency contraception: A survey of 506 Italian women

OBJECTIVE

To evaluate the reason for requesting emergency contraception (EC), previous use of contraceptive methods and provision route in a Family Planning Clinic in Italy.

METHODS

Women requesting EC were interviewed, through a questionnaire containing questions on demographic characteristics, about their reasons for requesting EC, their prior contraceptive use, their reasons for not using an effective contraceptive method (or possible reasons for its failure) and specifically about the so-called 'provision route' (i.e. whether and where they had previously requested EC receiving a negative response).

RESULTS

Almost 70% of all women requesting EC were aged between 18 and 25 years. Some 80% of all women were in a stable relationship with their partner, with fewer than 20% having had an occasional intercourse. The vast majority of women (83%) reported prior use of a modern contraceptive method, i.e. 64% with a condom, 27% for combined oral contraceptives and 1.1% for the intrauterine device (IUD). In addition, 15% of the women had used more than one method (oral pills and condoms). Concerning the reasons for requesting EC, condom breakage or slipping was the most frequently cited (64%), followed by totally unprotected intercourse (28%), failed withdrawal (5%) and forgetting one or more pill (only 1.1%).

CONCLUSIONS

More than one-third of the women interviewed had previously used an emergency contraceptive modality; although no one did so more than four times. Therefore, it can be inferred that-at least in the present series-EC had not been used as a routine contraceptive method. Finally, it seems clear that in Italy, even in large cities, information about the availability, proper usage and mechanism of action is lacking. This seems due to information being spread by word of mouth between peers and friends, with more formal communication channels lagging behind.

Effects of a preovulatory single low dose of mifepristone on ovarian function

OBJECTIVES

To investigate the effect of a single low dose of mifepristone on ovarian function, when administered in the preovulatory period.

METHODS

Healthy women with regular menstrual cycles were studied during two consecutive menstrual cycles. Either mifepristone or placebo was given in a randomized double-blind order when the leading follicle reached a diameter between 15 and 17 mm. Daily ultrasound and serum hormone measurements were obtained until follicular collapse. Statistical analysis was performed using Wilcoxon signed-rank test.

RESULTS

Eight women entered the study, although one woman had to be excluded afterwards from analysis because her LH surge had already appeared on the day of treatment. The LH surge was delayed from day 14 to 17 (P = 0.01). Mifepristone caused a 3-day delay in follicular collapse, occurring on day 16 in control cycles and on day 19 in mifepristone treatment cycles (P = 0.02). The median cycle length was 26 days in control cycles and 30 days in mifepristone treatment cycles (P = 0.03). Progesterone measurement 7 days after follicular collapse did not differ significantly between both cycles.

CONCLUSIONS

A single 10-mg dose of mifepristone administered during the preovulatory phase of the cycle delays the LH surge and postpones ovulation.

Is emergency contraception murder?

Hormonal emergency contraception (EC) is engendering fierce moral disagreement that is bleeding over into politics and policy. This paper considers Catholic positions on this issue, as they are the fullest and best developed. Its most extreme opponents, such as representatives of the Vatican, hold that EC is an abortifacient that should be banned. Moderates like Sulmasy believe that it should be available to women who have been raped when a negative pregnancy test suggests that fertilization has not yet taken place, and liberals, like Catholics for Free Choice, believe that it should be available to all women regardless of its mode of action. These positions depend in part on underlying philosophical presuppositions about when valuable life begins and scientific assumptions about how EC works. I argue that there are good reasons for rejecting the criterion of fertilization, and that the best current evidence strongly suggests that EC has no post-fertilization effects. These points by themselves undermine key objections to EC. I also show that none of the remaining considerations are sufficiently compelling to warrant overriding women's right to exercise religious, moral, and political agency in preventing undesired pregnancies.

Contraception, adolescence, and ethics in Brazil: are we prepared?

PURPOSE

to assess knowledge of pediatric residents attending adolescents, including ethical issues on contraceptive advice.

METHODS

A prospective study was conducted involving 75 residents in order to assess their knowledge, along with ethical issues involved, in clinical attendance of adolescents. The SPSS 13 software package was used for data analysis.

RESULTS

100% of interviewees stated that adolescents have the right to privacy during medical appointments. Yet, when asked from what age this privacy should be granted, 62% reported at any age. When questioned on whether an adolescent could be examined alone, without another person with them in the room, 50% of physicians answered yes and 50% no. 91.7% of interviewees felt that adolescents had the right to confidentiality and medical secrecy, but only 84.8% knew the contents of the Code of Medical Ethics regarding medical secrecy. A further 79.2% felt prepared to give advice on contraception to adolescents.

CONCLUSIONS

The attitudes held by pediatric residents on privacy, confidentiality and medical secrecy are highly ambiguous. The doctors interviewed were ill-prepared to deal with the issues of contraception in adolescence on both practical and legal levels.

Ectopic pregnancy following levonorgestrel emergency contraception: a case report

Use of levonorgestrel as emergency contraception is a safe and effective measure to prevent unwanted pregnancy. However, ectopic gestation in case of failure is a known risk. Access to levonorgestrel without a prescription in many countries has made it impossible to estimate the exact incidence of this potential adverse event. Thus, spontaneous reporting of cases serves to alert physicians to this possibility. We present a case of ectopic pregnancy following use of levonorgestrel emergency contraception. To our knowledge, this is the first case report from India following introduction of levonorgestrel emergency contraception in 2001.

Emergency contraception: a review

Emergency contraception (EC), also known as 'the morning after pill', or post-coital contraception, is a modality of preventing the establishment of a pregnancy after unprotected intercourse. Both a hormonal and an intrauterine form are available. Modern hormonal EC, with low side effects, was first proposed by Yuzpe in 1974. More recently, a new regimen, consisting of levonorgestrel administered alone, was introduced and found in clinical trials to be more effective (if taken as early as possible), and associated with less side effects than the Yuzpe regimen, which it has gradually replaced. The WHO developed another regimen based on the use of the selective progesterone receptor modulator (antiprogestin) mifepristone and conducted trials with different dosages. Intrauterine EC was first proposed by Lippes in 1976. It has the advantage of being applicable for almost a week and the disadvantage of a greater complexity. In addition, this modality is solely interceptive, acting by preventing implantation. Pregnancy rates reported following EC using an intrauterine device with more than 300 mm2 of copper are consistently low (0.1-0.2%).

The impact of over-the-counter availability of "Plan B" on teens' contraceptive decision making

In ruling on the over-the-counter status (OTC) of the emergency contraceptive, "Plan B", the US Food and Drug Administration (FDA) questioned whether younger adolescent females could adequately self-select and self-medicate. That determination requires a judgment of fact, regarding how increased emergency contraceptive availability would affect adolescents' behavior, and a judgment of values, regarding the acceptability of different outcomes. We present a general approach to such problems, using analytical and empirical methods grounded in behavioral decision research. We illustrate it with findings from 30 in-depth interviews and follow-up surveys, with adolescent females aged 13-19 in the Pittsburgh area reporting how Plan B availability would affect three decisions (having sex, choosing contraceptives, using Plan B). Although the FDA expressed concern about younger teens using Plan B as their primary form of contraception, neither younger nor older teens revealed such an intention. However, teens preferred easier availability, should emergency contraceptive be needed. Incorporating an understanding of teens' decision-related perspectives can make such policies more predictable and transparent.

Emergency contraception, myths and facts

Emergency contraception has the potential to reduce the United States unintended pregnancy rate by half. This article discusses the evidence on the safety and efficacy of emergency contraception, its side effects, as well as its mechanisms of action. Emergency contraception availability presents many opportunities for enhanced contraceptive care, beyond the obvious lapse in condom use, and evidence is lacking for contraindications to this expanded role. This article concludes that clinicians caring for women of reproductive age should recognize the importance of ready access to this medication to help prevent unintended pregnancies.

Factors associated with safe sex among public school students in Minas Gerais, Brazil

A cross-sectional study was conducted to evaluate factors associated with safe sex among sexually active public school students in Minas Gerais State, Brazil. The study focused on correlations between the variables gender, age, schooling, current grade, ethnicity, religion, importance attributed to religion, mothers' education, prior exposure to any sex education, promotion of juvenile protagonism, and participation by health professionals in school activities and consistent condom use with casual or stable partners and with use of other modern contraceptive methods. Bivariate and multivariate logistic regression analyses were used. Male gender and participation by health professionals in school activities were positively associated with all indicators of safe sex, and maternal schooling of more than eight years was positively associated with consistent condom use with casual and stable partners. Secondary (versus elementary) schooling and age (older) were inversely associated with consistent condom use with casual and stable partners, respectively. Ascribing greater importance to religion and Evangelical religion were negatively associated with use of modern contraceptives in the last sexual intercourse.

In vivo assessment of the human sperm acrosome reaction and the expression of glycodelin-A in human endometrium after levonorgestrel-emergency contraceptive pill administration

BACKGROUND

The objectives were firstly to assess acrosome reaction (AR) status of spermatozoa following uterine flushing, secondly to measure levonorgestrel (LNG) levels in serum and in uterine flushing fluid and finally to measure endometrial glycodelin-A expression after administration of LNG as a form of emergency contraception (EC).

METHODS

Forty-eight experiments were conducted on 15 regularly menstruating women. Four groups were formed based on different intercourse to treatment interval and treatment to recovery of spermatozoa and the biopsies.

RESULTS

Twenty-four and forty-eight hours after treatment, there were 14.5 +/- 3.9 x 10(6) and 17.3 +/- 6.8 x 10(6) sperm recovered from the uterus, respectively. There were no differences between the AR rate and the endometrial glycodelin-A staining intensity in an LNG or placebo treated cycles. The LNG in uterine flushing medium represented 1.38% of the values observed in serum 24 h after the LNG intake.

CONCLUSIONS

Twenty-four and forty-eight hours after administration of EC, neither the proportion of AR sperm, nor the glycodelin-A level was influenced by 1.5 mg of LNG. LNG did not impair the cervical mucus either because viable spermatozoa were found in the genital tract 36-60 h after coitus and 24-48 h after LNG intake. The mechanism of action of LNG as EC remains unknown.