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Gawron LM, Kaiser JE, Gero A, Sanders JN, Johnstone EB, Turok DK. Pharmacodynamic evaluation of the etonogestrel contraceptive implant initiated midcycle with and without ulipristal acetate: An exploratory study. Contraception 2024; 132:110370. [PMID: 38232940 PMCID: PMC10922844 DOI: 10.1016/j.contraception.2024.110370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 01/08/2024] [Accepted: 01/10/2024] [Indexed: 01/19/2024]
Abstract
OBJECTIVE To estimate the incidence of ovulation suppression within five days of etonogestrel 68 mg implant insertion in the presence of a dominant follicle with and without same-day ulipristal acetate. STUDY DESIGN This single site non-masked, exploratory randomized trial recruited people age 18-35 years with regular menstrual cycles, no pregnancy risk, and confirmed ovulatory function. We initiated transvaginal ultrasound examinations on menstrual day 7-9 and randomized participants 1:1 to etonogestrel implant alone or with concomitant ulipristal acetate 30 mg oral when a dominant follicle reached ≥14 mm in diameter. We completed daily sonography and serum hormone levels for up to seven days or transitioned to labs alone if sonographic follicular rupture occurred. We defined ovulation as follicular rupture followed by progesterone >3 ng/mL. We calculated point estimates, risk ratios and 95% confidence intervals for ovulation for each group. Ovulation suppression of ≥44% in either group (the follicular rupture suppression rate with oral levonorgestrel emergency contraception), would prompt future method testing. RESULTS From October 2020 to October 2022, we enrolled 40 people and 39 completed primary outcome assessments: 20 with etonogestrel implant alone (mean follicular size at randomization: 15.2 mm ± 0.9 mm) and 19 with etonogestrel implant + ulipristal acetate (mean follicular size at randomization: 15.4 mm ± 1.2 mm, p = 0.6). Ovulation suppression occurred in 13 (65%) of etonogestrel implant-alone participants (Risk ratio 0.6 (95% CI: 0.3, 1.1), p = 0.08) and seven (37%) of implant + ulipristal acetate participants. CONCLUSIONS Ovulation suppression of the etonogestrel implant alone exceeds threshold testing for future research while the implant + ulipristal acetate does not. IMPLICATIONS Data are lacking on midcycle ovulation suppression for the etonogestrel implant with and without oral ulipristal acetate. In this exploratory study, ovulation suppression occurred in 65% of implant participants and 37% of implant + ulipristal acetate participants. Ovulation suppression of the implant alone exceeds threshold testing for future emergency contraception research.
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Affiliation(s)
- Lori M Gawron
- Division of Family Planning, Department of Obstetrics and Gynecology, University of Utah, Salt Lake City, UT, USA.
| | - Jennifer E Kaiser
- Division of Family Planning, Department of Obstetrics and Gynecology, University of Utah, Salt Lake City, UT, USA
| | - Alexandra Gero
- Division of Family Planning, Department of Obstetrics and Gynecology, University of Utah, Salt Lake City, UT, USA
| | - Jessica N Sanders
- Division of Family Planning, Department of Obstetrics and Gynecology, University of Utah, Salt Lake City, UT, USA
| | - Erica B Johnstone
- Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, University of Utah, Salt Lake City, UT, USA
| | - David K Turok
- Division of Family Planning, Department of Obstetrics and Gynecology, University of Utah, Salt Lake City, UT, USA
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The potential for intramuscular depot medroxyprogesterone acetate as a self-bridging emergency contraceptive. Contracept X 2020; 3:100050. [PMID: 33367229 PMCID: PMC7749364 DOI: 10.1016/j.conx.2020.100050] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 11/17/2020] [Accepted: 11/17/2020] [Indexed: 12/30/2022] Open
Abstract
Objective To examine the rate of ovulatory disruption when intramuscular depot medroxyprogesterone acetate (DMPA) is administered across graded stages of dominant follicle development. Study design We assigned enrolled participants to one of three preassigned dominant follicle size groups: 12-14 mm, 15–17 mm and ≥ 18 mm. We followed dominant follicles via serial transvaginal ultrasound (TVUS) until the follicles reached their assigned size, at which time we administered DMPA. For 5 consecutive days thereafter, we followed the follicles via TVUS to observe follicle rupture and obtained serum luteinizing hormone (LH), estradiol, and progesterone concentrations. In the following 2 weeks, we collected serum progesterone concentrations twice weekly to detect possible ovulatory delay or dysfunction. We also collected serum medroxyprogesterone acetate (MPA) concentrations at 1 and 24 h after DMPA administration to examine against ovulatory outcomes. Results Twenty-six of 29 enrolled women completed the study. DMPA suppressed ovulation in 17/26 (65%) and caused ovulatory dysfunction in 1/26 (4%) participants. Larger follicles were more likely to rupture despite DMPA (12–14 mm: 0/10 (0%); 15–17 mm: 3/10 (30%); ≥ 18 mm: 6/6 (100%); p < .01). Pre-DMPA LH concentrations ranged from 13.8 to 93.7 IU/L (mean 49.0 IU/L) in cases of follicle rupture. We observed no cases of follicle rupture when DMPA was administered through cycle day 12. All 24-h MPA concentrations exceeded those needed for ovulation suppression. Conclusion DMPA suppressed and additionally disrupted ovulation in 65% and 4% of observed cycles, respectively. DMPA may provide effective emergency contraception as well as ongoing contraception if administered prior to an expected ovulation and specifically before the LH surge. Implications DMPA may be an alternative form of emergency contraception that can also self-bridge to ongoing contraception. As ovulation was not observed among any follicles when DMPA was given through cycle day 12, women who initiate DMPA up through cycle day 12 may not require backup contraception.
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Zaami S, Signore F, Baffa A, Votino R, Marinelli E, Del Rio A. Emergency contraception: unresolved clinical, ethical and legal quandaries still linger. Panminerva Med 2020; 63:75-85. [PMID: 32329333 DOI: 10.23736/s0031-0808.20.03921-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Emergency contraception (EC) has been prescribed for decades, in order to lessen the risk of unplanned and unwanted pregnancy following unprotected intercourse, ordinary contraceptive failure, or rape. EC and the linked aspect of unintended pregnancy undoubtedly constitute highly relevant public health issues, in that they involve women's self-determination, reproductive freedom and family planning. Most European countries regulate EC access quite effectively, with solid information campaigns and supply mechanisms, based on various recommendations from international institutions herein examined. However, there is still disagreement on whether EC drugs should be available without a physician's prescription and on the reimbursement policies that should be implemented. In addition, the rights of health care professionals who object to EC on conscience grounds have been subject to considerable legal and ethical scrutiny, in light of their potential to damage patients who need EC drugs in a timely fashion. Ultimately, reproductive health, freedom and conscience-based refusal on the part of operators are elements that have proven extremely hard to reconcile; hence, it is essential to strike a reasonable balance for the sake of everyone's rights and well-being.
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Affiliation(s)
- Simona Zaami
- Section of Legal Medicine, Department of Anatomical, Histological, Forensic and Orthopedic Sciences, Sapienza University, Rome, Italy -
| | - Fabrizio Signore
- Department of Obstetrics and Gynecology, Misericordia Hospital, Grosseto, Italy
| | - Alberto Baffa
- Department of Obstetrics and Gynecology, Misericordia Hospital, Grosseto, Italy
| | - Raffaella Votino
- Department of Obstetrics and Gynecology, Misericordia Hospital, Grosseto, Italy
| | - Enrico Marinelli
- Section of Legal Medicine, Department of Anatomical, Histological, Forensic and Orthopedic Sciences, Sapienza University, Rome, Italy
| | - Alessandro Del Rio
- Section of Legal Medicine, Department of Anatomical, Histological, Forensic and Orthopedic Sciences, Sapienza University, Rome, Italy
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Allaway H, Chizen D, Adams G, Pierson R. Effects of a single 20 mg dose of letrozole on ovarian function post dominant follicle selection: an exploratory randomized controlled trial. J Ovarian Res 2017; 10:6. [PMID: 28107821 PMCID: PMC5251318 DOI: 10.1186/s13048-017-0303-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 01/16/2017] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Our objective was to explore the impact of a single dose of an aromatase inhibitor (letrozole) administered at defined times of the follicular phase or immediately after ovulation on dominant follicle development, luteogenesis and new follicle wave emergence. METHODS A prospective pilot study using a randomized complete block, controlled, open label design was conducted at an academic clinical research center. Forty-five healthy, female volunteers (25.5 ± 0.9 years, BMI 25.0 ± 0.6 kg/m2) who had not taken hormonal contraceptives for a minimum of 2 months were recruited. A 20 mg dose of Letrozole was administered once orally in each of 3 groups when the dominant follicle reached a diameter of 1) 12 mm, 2) 18 mm, 3) the first day following ovulation (post-ovulation), or 4) treatment was withheld (control). Serial ultrasonography and phlebotomy began on day 4 of the menstrual cycle and continued for 1.5 menstrual cycles. Participants recorded menses and daily events in a life events calendar for the duration of the study. Demographic and single point measurements were compared among groups by ANOVA. Changes in hormone concentrations over time were compared among groups by repeated measures ANOVA. Kruskal-Wallis tests were used for non-normally distributed data. RESULTS The dominant follicle in all treatment groups ovulated. There were no differences among experimental groups in peak follicle diameter, follicular growth rate, endometrial thickness at ovulation or inter-ovulatory interval. Plasma concentrations of estradiol dropped, while FSH and LH concentrations rose following treatment in all treatment groups. Plasma FSH and LH concentrations were higher in the 18 mm group compared to the 12 mm and post-ovulation groups (P < 0.02). CONCLUSION Administration of a single 20 mg dose of Letrozole at the times of the menstrual cycle we examined did not induce dominant follicle regression or failure of corpus luteum formation. Letrozole-induced suppression of estradiol synthesis by the dominant follicle was not detrimental to follicle growth or ovulation following follicle selection, likely due to increased circulating concentrations of FSH and LH resulting from a lack of estradiol-induced suppression of the hypothalamic-pituitary-ovarian axis. TRIALS REGISTRATION NUMBER Clinical trials registration number NCT01046578 .
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Affiliation(s)
- H.C.M. Allaway
- Department of Obstetrics, Gynecology & Reproductive Sciences, College of Medicine, University of Saskatchewan, 103 Hospital Drive, Saskatoon, SK S7N 0 W8 Canada
- Present Address: Department of Kinesiology, Pennsylvania State University, State College, PA USA
| | - D.R. Chizen
- Department of Obstetrics, Gynecology & Reproductive Sciences, College of Medicine, University of Saskatchewan, 103 Hospital Drive, Saskatoon, SK S7N 0 W8 Canada
| | - G.P. Adams
- Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK Canada
| | - R.A. Pierson
- Department of Obstetrics, Gynecology & Reproductive Sciences, College of Medicine, University of Saskatchewan, 103 Hospital Drive, Saskatoon, SK S7N 0 W8 Canada
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Lira-Albarrán S, Larrea-Schiavon MF, González L, Durand M, Rangel C, Larrea F. The effects of levonorgestrel on FSH-stimulated primary rat granulosa cell cultures through gene expression profiling are associated to hormone and folliculogenesis processes. Mol Cell Endocrinol 2017; 439:337-345. [PMID: 27663078 DOI: 10.1016/j.mce.2016.09.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Revised: 09/19/2016] [Accepted: 09/19/2016] [Indexed: 12/18/2022]
Abstract
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.
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Affiliation(s)
- Saúl Lira-Albarrán
- Department of Reproductive Biology, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Avenida Vasco de Quiroga No. 15, Ciudad de México 14080, México.
| | - Marco F Larrea-Schiavon
- Department of Computational Genomics, Instituto Nacional de Medicina Genómica, Periférico Sur No. 4809, Ciudad de México 14610, México.
| | - Leticia González
- Department of Reproductive Biology, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Avenida Vasco de Quiroga No. 15, Ciudad de México 14080, México.
| | - Marta Durand
- Department of Reproductive Biology, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Avenida Vasco de Quiroga No. 15, Ciudad de México 14080, México.
| | - Claudia Rangel
- Department of Computational Genomics, Instituto Nacional de Medicina Genómica, Periférico Sur No. 4809, Ciudad de México 14610, México.
| | - Fernando Larrea
- Department of Reproductive Biology, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Avenida Vasco de Quiroga No. 15, Ciudad de México 14080, México.
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Contraception d’urgence. JOURNAL OF OBSTETRICS AND GYNAECOLOGY CANADA 2016; 38:S143-S152. [DOI: 10.1016/j.jogc.2016.09.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Peck R, Rella W, Tudela J, Aznar J, Mozzanega B. Does levonorgestrel emergency contraceptive have a post-fertilization effect? A review of its mechanism of action. LINACRE QUARTERLY 2016; 83:35-51. [PMID: 27833181 PMCID: PMC5102184 DOI: 10.1179/2050854915y.0000000011] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
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.
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Affiliation(s)
- Rebecca Peck
- Florida State University, College of Medicine, Daytona Beach, Florida, USA
| | - Walter Rella
- Institut für Medizinische Anthropologie und Bioethik (IMABE), Wien, Austria
| | - Julio Tudela
- Observatory Bioethics of the Catholic University of Valencia, Spain
| | - Justo Aznar
- Life Sciences Institute of the Catholic University of Valencia, Spain
| | - Bruno Mozzanega
- Gynecology in the Department of Woman's and Child's Health, University of Padua, Obstetrics and Gynecology Unit, University of Padova, Italy
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Abstract
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.
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Koyama A, Hagopian L, Linden J. Emerging options for emergency contraception. CLINICAL MEDICINE INSIGHTS. REPRODUCTIVE HEALTH 2013; 7:23-35. [PMID: 24453516 PMCID: PMC3888080 DOI: 10.4137/cmrh.s8145] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Emergency post-coital contraception (EC) is an effective method of preventing pregnancy when used appropriately. EC has been available since the 1970s, and its availability and use have become widespread. Options for EC are broad and include the copper intrauterine device (IUD) and emergency contraceptive pills such as levonorgestrel, ulipristal acetate, combined oral contraceptive pills (Yuzpe method), and less commonly, mifepristone. Some options are available over-the-counter, while others require provider prescription or placement. There are no absolute contraindications to the use of emergency contraceptive pills, with the exception of ulipristal acetate and mifepristone. This article reviews the mechanisms of action, efficacy, safety, side effects, clinical considerations, and patient preferences with respect to EC usage. The decision of which regimen to use is influenced by local availability, cost, and patient preference.
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Affiliation(s)
- Atsuko Koyama
- Department of Pediatric Emergency Medicine, Boston Medical Center, Boston University School of Medicine, Boston, Massachusetts, USA
| | - Laura Hagopian
- Department of Emergency Medicine, Boston Medical Center, Boston University School of Medicine, Boston, Massachusetts, USA
| | - Judith Linden
- Department of Emergency Medicine, Boston Medical Center, Boston University School of Medicine, Boston, Massachusetts, USA
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Abstract
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.
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Abstract
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).
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13
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Hormonal evaluation and midcycle detection of intrauterine glycodelin in women treated with levonorgestrel as in emergency contraception. Contraception 2010; 82:526-33. [DOI: 10.1016/j.contraception.2010.05.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2010] [Revised: 05/06/2010] [Accepted: 05/19/2010] [Indexed: 11/23/2022]
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Gemzell-Danielsson K, Meng CX. Emergency contraception: potential role of ulipristal acetate. Int J Womens Health 2010; 2:53-61. [PMID: 21072297 PMCID: PMC2971744 DOI: 10.2147/ijwh.s5865] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2010] [Indexed: 12/30/2022] Open
Abstract
Unintended pregnancy is a global reproductive health problem. Emergency contraception (EC) provides women with a safe means of preventing unwanted pregnancies after having unprotected intercourse. While 1.5 mg of levonorgestrel (LNG) as a single dose or in 2 doses with 12 hours apart is the currently gold standard EC regimen, a single dose of 30 mg ulipristal acetate (UPA) has recently been proposed for EC use up to 120 hours of unprotected intercourse with similar side effect profiles as LNG. The main mechanism of action of both LNG and UPA for EC is delaying or inhibiting ovulation. However, the 'window of effect' for LNG EC seems to be rather narrow, beginning after selection of the dominant follicular and ending when luteinizing hormone peak begins to rise, whereas UPA appears to have a direct inhibitory effect on follicular rupture which allows it to be also effective even when administered shortly before ovulation, a time period when use of LNG is no longer effective. These experimental findings are in line with results from a series of clinical trials conducted recently which demonstrate that UPA seems to have higher EC efficacy compared to LNG. This review summarizes some of the data available on UPA used after unprotected intercourse with the purpose to provide evidence that UPA, a new type of second-generation progesterone receptor modulator, represents a new evolutionary step in EC treatment.
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Affiliation(s)
- Kristina Gemzell-Danielsson
- Department of Women's and Children's Health, Division of Obstetrics and Gynecology, Karolinska Institutet, Stockholm, Sweden
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Affiliation(s)
- Vivian W Y Leung
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada
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16
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Black KI. Developments and challenges in emergency contraception. Best Pract Res Clin Obstet Gynaecol 2009; 23:221-31. [DOI: 10.1016/j.bpobgyn.2008.11.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2008] [Accepted: 11/07/2008] [Indexed: 12/30/2022]
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Benagiano G, Bastianelli C, Farris M. Selective progesterone receptor modulators 2: use in reproductive medicine. Expert Opin Pharmacother 2008; 9:2473-85. [PMID: 18778185 DOI: 10.1517/14656566.9.14.2473] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Abstract
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%).
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Affiliation(s)
- Carlo Bastianelli
- Department of Gynaecologic Sciences, Perinatology and Child Care, University la Sapienza, Rome, Italy.
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Critchley HOD, Baird DT. Endometrial effects of hormonal contraception. REPRODUCTIVE MEDICINE AND ASSISTED REPRODUCTIVE TECHNIQUES 2008. [DOI: 10.3109/9780203091500.039] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Campbell JW, Busby SC, Steyer TE. Attitudes and beliefs about emergency contraception among patients at academic family medicine clinics. Ann Fam Med 2008; 6 Suppl 1:S23-7. [PMID: 18195304 PMCID: PMC2203385 DOI: 10.1370/afm.744] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
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.
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Affiliation(s)
- John W Campbell
- Trident-Medical University of South Carolina Family Medicine Residency Program, Charleston, South Carolina 29406, USA.
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Trussell J, Jordan B. Mechanism of action of emergency contraceptive pills. Contraception 2006; 74:87-9. [PMID: 16860044 DOI: 10.1016/j.contraception.2006.03.028] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2006] [Accepted: 03/24/2006] [Indexed: 12/30/2022]
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Baerwald AR, Olatunbosun OA, Pierson RA. Effects of oral contraceptives administered at defined stages of ovarian follicular development. Fertil Steril 2006; 86:27-35. [PMID: 16764869 DOI: 10.1016/j.fertnstert.2005.12.046] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2005] [Revised: 12/14/2005] [Accepted: 12/14/2005] [Indexed: 10/24/2022]
Abstract
OBJECTIVE To elucidate the effects of initiating oral contraceptives (OC) at defined stages of ovarian follicle development. DESIGN Prospective longitudinal study. SETTING Healthy volunteers in an academic research environment. PATIENT(S) Forty-five healthy women between the ages of 18 and 35 years, randomized to initiate OC when a follicle diameter of 10, 14, or 18 mm was first detected. INTERVENTION(S) The OC administration at defined stages of dominant follicle development. MAIN OUTCOME MEASURE(S) Fates of all dominant follicles and serum concentrations of E(2)-17beta, LH, and P before and after initiating OC. RESULT(S) No ovulations (0/16) were observed when OC use was initiated at a follicle diameter of 10 mm, 4/14 (29%) follicles ovulated when OC were initiated at 14 mm, and 14/15 (93%) ovulated when OC were initiated at 18 mm. When ovulation did not occur, follicles regressed or became anovulatory cysts. Peak LH and E(2) levels were lowest in the 10-mm group, moderate in the 14-mm group, and greatest in the 18-mm group. Peak endocrine levels in all treatment groups were lower than the historic reference group. CONCLUSION(S) Follicular development, ovulation, and endocrine concentrations were not suppressed effectively when OC were initiated at late stages of dominant follicle development.
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Affiliation(s)
- Angela R Baerwald
- Department of Obstetrics, Gynecology and Reproductive Sciences, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
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Croxatto HB, Brache V, Massai R, Alvarez F, Forcelledo ML, Pavez M, Cochon L, Salvatierra AM, Faundes A. Feasibility study of Nestorone®–ethinylestradiol vaginal contraceptive ring for emergency contraception. Contraception 2006; 73:46-52. [PMID: 16371294 DOI: 10.1016/j.contraception.2005.06.071] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2004] [Revised: 05/05/2005] [Accepted: 06/17/2005] [Indexed: 11/16/2022]
Abstract
OBJECTIVE The Nestorone/ethinylestradiol (NES/EE) vaginal ring is being developed as a regular contraceptive method by the Population Council. This ring is designed to release NES 150 microg/day and EE 15 microg/day during 1 year. Here, we report a Phase I clinical trial to determine the usefulness of this ring for emergency contraception. To that end, we tested the ability of this ring to interfere with ovulation when it is inserted during the follicular phase. METHOD Forty-eight women protected from the risk of pregnancy by nonhormonal methods were divided into three groups, which differed by the size of the dominant follicle at the time of ring insertion: 12-14 mm (n = 16), 15-17 mm (n = 18) and >or=18 mm (n = 14) diameter. The NES/EE ring was left in the vagina for 7 consecutive days, after which it was removed. The growth of the leading follicle and plasma levels of estradiol, progesterone (P), luteinizing hormone (LH) and follicle stimulating hormone (FSH) in the ensuing 5 days after ring insertion were determined. Afterwards, steroid hormones were measured twice a week, until menses took place. All women had a control cycle before the ring cycle, and the range of maximum follicular diameter assigned to each volunteer was the same for the control and the ring cycle at the time when placebo was ingested or the ring inserted. RESULTS During the 5-day period after ring insertion with follicles 12-17 mm, ovulation was absent in 25 of 34 cycles (p < .01 vs. control), and ovulatory dysfunction (absent, blunted or mistimed LH peak) occurred in 8 of the 9 remaining cycles (33/34 ovulatory processes altered; p < .005 vs. control). After ring insertion with follicles >or=18 mm in diameter, ovulation did not occur in 2 of 14 cycles or was dysfunctional in 7 of the 12 remaining cycles (9/14 ovulatory processes altered; p<.025 vs. control). Altogether, 87.5% of ring cycles (42/48) had either no ovulation or ovulatory dysfunction in the 5-day study period, in contrast to 39.6% (19/48 cycles) in control cycles (p < .001). Among follicles that failed to rupture within the 5-day study period, none ruptured later on in the ring-treated cycles, while 9 of 16 did so in control cycles. Sixty-two percent of ring-treated cycles were shorter than 24 days. Nausea, vaginal discharge and abdominal pain were the most frequently reported adverse events during ring use. CONCLUSION Interference with 87.5% of ovulatory processes, without ovulation occurring later in the cycle and shortening of cycle length, suggests the NES/EE ring may be used as an emergency contraceptive method, with the potential advantage of providing continuing contraception after it has performed its emergency function.
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Affiliation(s)
- Horatio B Croxatto
- Instituto Chileno de Medicina Reproductiva, Jose Ramon Gutierrez 295, Apt 3, Santiago, Chile.
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Abstract
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.
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Brito KS, Bahamondes L, Nascimento JAA, de Santis L, Munuce MJ. The in vitro effect of emergency contraception doses of levonorgestrel on the acrosome reaction of human spermatozoa. Contraception 2005; 72:225-8. [PMID: 16102561 DOI: 10.1016/j.contraception.2005.04.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2005] [Accepted: 04/25/2005] [Indexed: 12/30/2022]
Abstract
INTRODUCTION The aim of this study was to evaluate the effect of three concentrations of levonorgestrel (LNG) comparable to the levels found in serum following ingestion of LNG as emergency contraception (EC) on the acrosome reaction (AR) of capacitated and noncapacitated spermatozoa of fertile men. MATERIALS AND METHODS A total of 24 semen samples from three fertile men were evaluated. The spermatozoa were selected by Percoll gradient. Twelve samples were subsequently incubated with human tubal fluid medium supplemented with bovine serum albumin (HTF/BSA) for 20 h under capacitating conditions. The capacitated spermatozoa and the spermatozoa from the remaining 12 samples were exposed to LNG at 1, 10 and 100 ng/mL, to follicular fluid (FF) (20 %v/v) and to HTF medium. The ratio of live to dead spermatozoa was assessed after 1, 2 and 3 h of incubation at 37 degrees C and 5% CO2. After 30 min of exposure to the different LNG concentrations, aliquots were divided into two parts. In the first part, spermatozoa were immediately stained with Hoescht 33258 and fluorescein isothiocyanate-pisum sativum agglutinin (FITC-PSA) in order to assess AR rate and to repeat evaluation of the live-to-dead ratio. After 3 h of incubation, the remaining part of the aliquots were submitted to the same procedures. Each concentration of LNG was then compared with FF and HTF medium as positive and negative controls, respectively. RESULTS The results showed that in vitro exposure to the three different LNG concentrations did not induce AR. CONCLUSION This study failed to show any in vitro effect on AR of LNG concentrations similar to those found in serum following intake of LNG as EC. If this effect exists or if there is any other that influences sperm fertilizing capacity, in vitro experiments are probably not an appropriate way of testing it.
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Affiliation(s)
- Karen Saboya Brito
- Human Reproduction Unit, Department of Obstetrics and Gynecology, School of Medicine, Universidade Estadual de Campinas (UNICAMP), 13084-971 Campinas, Brazil
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Durand M, Seppala M, Cravioto MDC, Koistinen H, Koistinen R, González-Macedo J, Larrea F. Late follicular phase administration of levonorgestrel as an emergency contraceptive changes the secretory pattern of glycodelin in serum and endometrium during the luteal phase of the menstrual cycle. Contraception 2005; 71:451-7. [PMID: 15914136 DOI: 10.1016/j.contraception.2005.01.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2004] [Accepted: 01/10/2005] [Indexed: 10/25/2022]
Abstract
This study examined serum glycodelin concentrations and endometrial expression during the luteal phase following oral administration of levonorgestrel (LNG) at different stages of the ovarian cycle. Thirty women were recruited and allocated into three groups. All groups were studied during two consecutive cycles, a control cycle and the treatment cycle. In the treatment cycle, each woman received two doses of 0.75 mg LNG taken 12 h apart on days 3-4 before the luteinizing hormone (LH) surge (Group 1), at the time of LH rise (Group 2) and 48 h after the rise in LH was detected (Group 3). Serum progesterone (P) and glycodelin were measured daily during the luteal phase, and an endometrial biopsy was taken at day LH +9 for immunohistochemical glycodelin-A staining. In Group 1, serum P levels were significantly lower, serum glycodelin levels rose earlier and endometrial glycodelin-A expression was weaker than in Groups 2 and 3, in which no differences were found between control and treatment cycles. Levonorgestrel taken for emergency contraception (EC) prior to the LH surge alters the luteal phase secretory pattern of glycodelin in serum and endometrium. Based on the potent gamete adhesion inhibitory activity of glycodelin-A, the results may account for the action of LNG in EC in those women who take LNG before the LH surge.
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Affiliation(s)
- Marta Durand
- Department of Reproductive Biology, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City 14000, Mexico
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Croxatto HB, Brache V, Pavez M, Cochon L, Forcelledo ML, Alvarez F, Massai R, Faundes A, Salvatierra AM. Pituitary–ovarian function following the standard levonorgestrel emergency contraceptive dose or a single 0.75-mg dose given on the days preceding ovulation. Contraception 2004; 70:442-50. [PMID: 15541405 DOI: 10.1016/j.contraception.2004.05.007] [Citation(s) in RCA: 117] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2003] [Revised: 03/17/2004] [Accepted: 05/19/2004] [Indexed: 11/24/2022]
Abstract
We assessed to what extent the standard dose of levonorgestrel (LNG), used for emergency contraception, or a single dose (half dose), given in the follicular phase, affects the ovulatory process during the ensuing 5-day period. Fifty-eight women were divided into three groups according to timing of treatment. Each woman contributed with three treatment cycles separated by resting cycles. All received placebo in one cycle, and standard or single dose in two other cycles, in a randomized order. The diameter of the dominant follicle determined the time of treatment. Each woman had the same diameter assigned for all her treatments. Diameters were grouped into 33 categories: 12-14, 15-17 or 18-20 mm. Follicular rupture failed to occur during the 5-day period in 44%, 50% and 36% of cycles with the standard, half dose and placebo, respectively. Ovulatory dysfunction, characterized by follicular rupture associated with absent, blunted or mistimed gonadotropin surge, occurred in 35%, 36% and 5% of standard, single dose or placebo cycles, respectively. In conclusion, LNG can disrupt the ovulatory process in 93% of cycles treated when the diameter of the dominant follicle is between 12 and 17 mm. It is highly probable that this mode of action fully accounts for the contraceptive efficacy as well as the failure rate of this method. The present data suggest that half the dose may be as effective as the standard dose.
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Affiliation(s)
- H B Croxatto
- Instituto Chileno de Medicina Reproductiva, J. V. Lastarria 29, Department 101, Santiago, Chile.
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Trussell J, Ellertson C, Stewart F, Raymond EG, Shochet T. The role of emergency contraception. Am J Obstet Gynecol 2004; 190:S30-8. [PMID: 15105796 DOI: 10.1016/j.ajog.2004.01.063] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
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.
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Affiliation(s)
- James Trussell
- Woodrow Wilson School of Public and International Affairs, Office of Population Research, Princeton University, Princeton, NJ 08544, USA.
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Abstract
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.
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Affiliation(s)
- A Faúndes
- Department of Gynecology and Obstetrics, Universidade Estadual de Campinas, Campinas, SP, Brazil.
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Contraception d’urgence. JOURNAL OF OBSTETRICS AND GYNAECOLOGY CANADA 2003. [DOI: 10.1016/s1701-2163(16)30127-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Mikolajczyk R, Spinnato JA, Stanford JB, Mikolajczyk R, Spinnato JA, Stanford JB. Uncertainty in estimating the day of ovulation causes overestimation of the role of ovulation disturbance on the effectiveness of the Yuzpe method of emergency contraception. Contraception 2003; 68:69-70; author reply 70-1. [PMID: 12878291 DOI: 10.1016/s0010-7824(03)00100-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Mikolajczyk RT, Stanford JB. False risk attribution results in misleading assessment of the relationship between suppression of ovulation and the effectiveness of the Yuzpe regimen for emergency contraception. Contraception 2003; 67:333-5; author reply 335-7. [PMID: 12684157 DOI: 10.1016/s0010-7824(02)00479-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Trussell J, Ellertson C, Dorflinger L. Effectiveness of the Yuzpe regimen of emergency contraception by cycle day of intercourse: implications for mechanism of action. Contraception 2003; 67:167-71. [PMID: 12618250 DOI: 10.1016/s0010-7824(02)00486-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
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.
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Affiliation(s)
- James Trussell
- Office of Population Research, Wallace Hall, Princeton University, Princeton, NJ 08544, USA.
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Johansson E, Brache V, Alvarez F, Faundes A, Cochon L, Ranta S, Lovern M, Kumar N. Pharmacokinetic study of different dosing regimens of levonorgestrel for emergency contraception in healthy women. Hum Reprod 2002; 17:1472-6. [PMID: 12042264 DOI: 10.1093/humrep/17.6.1472] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Levonorgestrel (LNG) is a commonly used progestin for emergency contraception; however, little is known about its pharmacokinetics and optimal dose for use. METHODS Serum levels of LNG and sex hormone-binding globulin (SHBG) were measured in five women who received three different regimens: A: 0.75 mg LNG twice with a 12 h interval; B: 0.75 mg twice with a 24 h interval; and C: 1.50 mg in a single dose, with a washout period of 28 days between each treatment. Blood samples were taken before pill intake and at 1, 2, 4, 8 and 12 h after each dose, every 12 h up to day 4 and every 24 h until day 10. LNG and SHBG were measured in all samples. RESULTS Maximum LNG concentrations were of approximately 27 nmol/l for treatments A and B, and close to 40 nmol/l for treatment C. The area under the curve was significantly higher for treatment C during the first 12 h, and significantly lower for treatment B during the first 24 h. After 48 h and up to 9 days from onset of treatment, serum LNG levels were similar in all three regimens. SHBG levels remained stable for 24 h, decreasing to 60% of the initial value from day 5 until day 10, with no difference between regimens. CONCLUSIONS The similarity of LNG serum levels obtained with one single dose of 1.5 mg or two doses of 0.75 mg with a 12 h interval justify a clinical comparison of these two regimes.
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Affiliation(s)
- Elof Johansson
- Center for Biomedical Research, The Population Council, New York, NY, USA
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