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

Emergency contraception - A narrative review of literature

BACKGROUND

Emergency contraception includes several methods of contraception that can be used after unprotected sexual intercourse, after failure of any used method of contraception or in case of sexual abuse, to prevent pregnancy.

PURPOSE OF THE STUDY

The aim of the study was to analyze the available methods of emergency contraception, their mechanisms of action, efficacy, forms of administration, clinical applications and possible adverse effects.

MATERIAL AND METHOD

PubMed, Scopus and Cochrane datebases were searched for articles from 2010 to 2024 about emergency contraception.

RESULTS

The analyzed types of emergency contraception included single oral dose of ulipristal acetate, single oral dose of levonorgestrel and intrauterine system releasing levonorgestrel or copper intrauterine device. Taking emergency contraception in the optimum time according to the drug characteristics allows for avoiding pregnancy in more than 90% of cases (depending on the type of emergency contraception and time from unprotected intercourse). The analyzed literature shows that intrauterine copper intrauterine device is the most effective method of emergency contraception, also together with intrauterine system releasing levonorgestrel leading to the lowest rate of adverse effects.

CONCLUSIONS

Taking emergency contraception can result in various adverse effects, therefore it should be introduced after thorough analysis of woman's medical history, including gynecological and obstetric history and potential contraindications. Additionally, the patient should receive detailed information about the drug mechanism of efficacy and potential adverse effects.

Role of community-level emergency contraceptive pills awareness and possibilities of long-acting reversible or permanent methods in reducing unwanted births in Bangladesh: evidence from a nationwide cross-sectional survey

OBJECTIVE

This study aims to investigate the role of community-level emergency contraceptive pill (ECP) awareness in reducing unwanted births (UWBs) in Bangladesh and explore the regional variation in women's appropriateness to adopt long-acting reversible contraceptives or permanent methods (LARCPMs) based on their child desire.

DESIGN, SETTINGS AND PARTICIPANTS

We used data from the cross-sectional Bangladesh Demographic and Health Survey 2017-2018. We analysed the planning status of the last live birth 3 years preceding the survey of 20,127 ever-married women of reproductive age.

METHODS

Considering women were nested within clusters, a mixed-effect multiple logistic regression was implemented to investigate the association between community-level ECP awareness and UWB by controlling for the effects of contextual, individual, and household characteristics.

RESULTS

Only 3.7% of women belonged to communities with high ECP awareness. At the national level, 2% of women had UWB. About 2.1% of women who resided in communities of low ECP awareness had UWB, while UWB was only 0.5% among women residing in high ECP awareness communities. The odds of UWB was 71% lower among women who resided in high ECP awareness communities than among those who resided in communities with low ECP awareness. However, community-level ECP awareness could not avert mistimed birth. Dhaka, Chattogram and Rangpur held the highest share of UWB. Fertility persisted for 89% of the women who wanted no more children. Among women who wanted no more children, 15% were not using any method, 13% used traditional family planning methods and only 13% adopted LARCPM. These women mostly resided in Dhaka, followed by Chattogram and Rajshahi.

CONCLUSION

This study highlights the significant positive role of ECP awareness in reducing UWB in Bangladesh. Findings may inform policies aimed at increasing LARCPM adoption, particularly among women residing in Dhaka and Chattogram who want no more children.

[Preventive activities in women. PAPPS update 2022]

In the 2022 PAPPS update we present those specific preventive activities for women's health, except those related to cancer prevention (which are included in another document) and those aspects related to differential gender morbidity, a cross-cutting aspect for all working groups. Contraception is an essential preventive activity, considering basic the right to decide both the number of children and the time to have them. We must inform about the possible contraceptive methods, guaranteeing the monitoring of their safety, efficacy and effectiveness (tables are included on changing from one method to another to preserve contraceptive protection). We must inform about emergency contraception and propose it in the event of unprotected intercourse. All this will be done through opportunistic screening without requiring screening for thrombophilia or dyslipidemia, but for arterial hypertension. Pregnancy is an important life experience and the family doctor should not remain oblivious. We must be competent both in the preconception consultation (recommending the intake of folic acid, avoiding exposure to occupational and environmental risks, screening for certain pathologies and assessing the intake of drugs not indicated during pregnancy) and in the monitoring of pregnancy. Whether or not we monitor the pregnancy, we must not disregard its control, taking advantage of this period to promote healthy lifestyles and participating in the intercurrent processes that may occur. Menopause in general and osteoporosis in particular exemplify the strategy of medicalization of vital processes that has been followed from different instances and organizations. In our update we address the prevention and treatment of symptoms secondary to estrogen deprivation. We also propose the prevention of osteoporosis, including carrying out densitometry based on the risk of fracture in the next 10 years, and therefore densitometric screening is not recommended in women under 60 years of age. In risk assessment we recommend the use of the frax tool or better, the calibration of the risk of hip fracture with prevalence data from our setting. We linked the indication for treatment with the Z-Score (bone mineral density compared with women of the same age), as it is a condition associated with aging.

Factors associated with knowledge and use of the emergency contraceptive pill among ever-married women of reproductive age in Bangladesh: findings from a nationwide cross-sectional survey

OBJECTIVES

The study aimed to assess the prevalence and factors associated with knowledge and use of the emergency contraceptive pill (ECP) among ever-married women in Bangladesh.

METHODS

The study was based on a secondary dataset of the 2014 Bangladesh Demographic and Health Survey. Complete (weighted) data of 17,592 women aged 15-49 years were analysed.

RESULTS

The prevalence of having knowledge and use of the ECP among ever-married women in Bangladesh was 13.6% and 1.8%, respectively. Administrative region and type of residence (urban or rural), household wealth index, educational level (of both the woman and her spouse), spouse's occupation, number of living children, weight, current use of contraception and a history of pregnancy termination were positively associated with knowledge and use of the ECP.

CONCLUSION

A large proportion of Bangladeshi women of reproductive age had a lack of knowledge and use of the ECP. Nationwide reproductive health education programmes may improve the situation.

[Preventive activities in women's care]

A review is presented of the scientific evidence on preventive activities in women's care in relation to pregnancy follow-up, preventive activities in the planning and follow-up of contraceptive methods, preventive activities in menopause, and the prevention of osteoporotic fractures.

A Systematic Review and Meta-analysis of the Adverse Effects of Levonorgestrel Emergency Oral Contraceptive

INTRODUCTION

The levonorgestrel oral emergency contraceptive is well tolerated and effective, however its use is still limited, mainly due to safety concerns.

OBJECTIVE

This systematic review and meta-analysis aimed to summarize current evidence regarding the adverse events, and their prevalence, reported during the use of oral levonorgestrel emergency contraceptives.

METHODS

Four electronic databases and the US FDA Adverse Event Reporting System (FAERS) Public Dashboard were searched. Studies that reported or investigated safety outcomes or adverse reactions during the use of levonorgestrel as an emergency oral contraceptive were included. Data on study design, demographics of levonorgestrel and the control cohort, and reported adverse effects were extracted.

RESULTS

A total of 47 articles were included in this systematic review, from which it was shown that most of the adverse reactions were common and not serious. Uncommon adverse reactions identified included anorexia, ectopic pregnancy, exanthema, chloasma, miscarriage, and weight gain. Multiple serious adverse events, including convulsion, ectopic pregnancy, febrile neutropenia, stroke, abdominal hernia, anaphylaxis, cancer, ovarian cyst rupture, serious infections, and suicidal ideation, were reported. In addition, the prevalence of adverse events after a levonorgestrel 0.75 mg two-dose regimen and a levonorgestrel 1.5 mg single-dose regimen were not statistically different (p > 0.05).

CONCLUSIONS

The most common adverse effects of levonorgestrel were not serious. This systematic review shows that data regarding the adverse reactions of repeated use of levonorgestrel are scarce. Studies on the multiple uses of levonorgestrel emergency contraception are still required to ensure its safety.

Levonorgestrel emergency contraception and bodyweight

Objectives: Emergency contraception (EC) provides an opportunity to avoid an unwanted pregnancy following unprotected sexual intercourse (UPSI), failure of a regular contraceptive method, or after sexual assault. Two main methods are currently available: oral pills or the copper-T intrauterine device. In recent years there has been some debate regarding the efficacy of oral therapy in obese women. In this brief commentary we review new evidence, published after the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) referral of 2014, relating to the effect of obesity on the pharmacokinetics and clinical efficacy of levonorgestrel EC in light of some of the concerns that have been raised. Methods: A PubMed literature search ("levonorgestrel" and "emergency contraception") was conducted between 1 January 2005 to 31 March 2018; results from the main clinical trials are discussed. Additional literature known to the authors and identified from the reference lists of cited publications was included. Results: Overall, it should be noted that, in studies which determined pregnancy rates across different weight or BMI categories, the overall pregnancy rate was low (1-2%) and there was no direct evidence that lower levonorgestrel plasma levels contributed to an increased pregnancy rate in obese women. This conclusion was reached by the EMA referral in 2014 and they concluded that emergency contraceptive pills (ECPs) could be taken regardless of body weight or BMI, as soon as possible after UPSI. Since the EMA review, additional evidence has been published regarding this topic. This includes PK data (which can neither support, nor deny the previously submitted meta-analyses during the Article 31 Referral procedure), or re-analyses of the previously submitted data. Conclusions: Evidence published since the EMA referral in 2014 does not change the original conclusions of the agency, which recommended that ECPs could be taken regardless of body weight or BMI, as soon as possible after UPSI.

Interventions for emergency contraception

BACKGROUND

Emergency contraception (EC) is using a drug or copper intrauterine device (Cu-IUD) to prevent pregnancy shortly after unprotected intercourse. Several interventions are available for EC. Information on the comparative effectiveness, safety and convenience of these methods is crucial for reproductive healthcare providers and the women they serve. This is an update of a review previously published in 2009 and 2012.

OBJECTIVES

To determine which EC method following unprotected intercourse is the most effective, safe and convenient to prevent pregnancy.

SEARCH METHODS

In February 2017 we searched CENTRAL, MEDLINE, Embase, PsycINFO, CINAHL, Popline and PubMed, The Chinese biomedical databases and UNDP/UNFPA/WHO/World Bank Special Programme on Human Reproduction (HRP) emergency contraception database. We also searched ICTRP and ClinicalTrials.gov as well as contacting content experts and pharmaceutical companies, and searching reference lists of appropriate papers.

SELECTION CRITERIA

Randomised controlled trials including women attending services for EC following a single act of unprotected intercourse were eligible.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures recommended by Cochrane. The primary review outcome was observed number of pregnancies. Side effects and changes of menses were secondary outcomes.

MAIN RESULTS

We included 115 trials with 60,479 women in this review. The quality of the evidence for the primary outcome ranged from moderate to high, and for other outcomes ranged from very low to high. The main limitations were risk of bias (associated with poor reporting of methods), imprecision and inconsistency.Comparative effectiveness of different emergency contraceptive pills (ECP)Levonorgestrel was associated with fewer pregnancies than Yuzpe (estradiol-levonorgestrel combination) (RR 0.57, 95% CI 0.39 to 0.84, 6 RCTs, n = 4750, I² = 23%, high-quality evidence). This suggests that if the chance of pregnancy using Yuzpe is assumed to be 29 women per 1000, the chance of pregnancy using levonorgestrel would be between 11 and 24 women per 1000.Mifepristone (all doses) was associated with fewer pregnancies than Yuzpe (RR 0.14, 95% CI 0.05 to 0.41, 3 RCTs, n = 2144, I² = 0%, high-quality evidence). This suggests that if the chance of pregnancy following Yuzpe is assumed to be 25 women per 1000 women, the chance following mifepristone would be between 1 and 10 women per 1000.Both low-dose mifepristone (less than 25 mg) and mid-dose mifepristone (25 mg to 50 mg) were probably associated with fewer pregnancies than levonorgestrel (RR 0.72, 95% CI 0.52 to 0.99, 14 RCTs, n = 8752, I² = 0%, high-quality evidence; RR 0.61, 95% CI 0.45 to 0.83, 27 RCTs, n = 6052, I² = 0%, moderate-quality evidence; respectively). This suggests that if the chance of pregnancy following levonorgestrel is assumed to be 20 women per 1000, the chance of pregnancy following low-dose mifepristone would be between 10 and 20 women per 1000; and that if the chance of pregnancy following levonorgestrel is assumed to be 35 women per 1000, the chance of pregnancy following mid-dose mifepristone would be between 16 and 29 women per 1000.Ulipristal acetate (UPA) was associated with fewer pregnancies than levonorgestrel (RR 0.59; 95% CI 0.35 to 0.99, 2 RCTs, n = 3448, I² = 0%, high-quality evidence).Comparative effectiveness of different ECP dosesIt was unclear whether there was any difference in pregnancy rate between single-dose levonorgestrel (1.5 mg) and the standard two-dose regimen (0.75 mg 12 hours apart) (RR 0.84, 95% CI 0.53 to 1.33, 3 RCTs, n = 6653, I² = 0%, moderate-quality evidence).Mid-dose mifepristone was associated with fewer pregnancies than low-dose mifepristone (RR 0.73; 95% CI 0.55 to 0.97, 25 RCTs, n = 11,914, I² = 0%, high-quality evidence).Comparative effectiveness of Cu-IUD versus mifepristoneThere was no conclusive evidence of a difference in the risk of pregnancy between the Cu-IUD and mifepristone (RR 0.33, 95% CI 0.04 to 2.74, 2 RCTs, n = 395, low-quality evidence).Adverse effectsNausea and vomiting were the main adverse effects associated with emergency contraception. There is probably a lower risk of nausea (RR 0.63, 95% CI 0.53 to 0.76, 3 RCTs, n = 2186 , I² = 59%, moderate-quality evidence) or vomiting (RR 0.12, 95% CI 0.07 to 0.20, 3 RCTs, n = 2186, I² = 0%, high-quality evidence) associated with mifepristone than with Yuzpe. levonorgestrel is probably associated with a lower risk of nausea (RR 0.40, 95% CI 0.36 to 0.44, 6 RCTs, n = 4750, I² = 82%, moderate-quality evidence), or vomiting (RR 0.29, 95% CI 0.24 to 0.35, 5 RCTs, n = 3640, I² = 78%, moderate-quality evidence) than Yuzpe. Levonorgestrel users were less likely to have any side effects than Yuzpe users (RR 0.80, 95% CI 0.75 to 0.86; 1 RCT, n = 1955, high-quality evidence). UPA users were more likely than levonorgestrel users to have resumption of menstruation after the expected date (RR 1.65, 95% CI 1.42 to 1.92, 2 RCTs, n = 3593, I² = 0%, high-quality evidence). Menstrual delay was more common with mifepristone than with any other intervention and appeared to be dose-related. Cu-IUD may be associated with higher risks of abdominal pain than mifepristone (18 events in 95 women using Cu-IUD versus no events in 190 women using mifepristone, low-quality evidence).

AUTHORS' CONCLUSIONS

Levonorgestrel and mid-dose mifepristone (25 mg to 50 mg) were more effective than Yuzpe regimen. Both mid-dose (25 mg to 50 mg) and low-dose mifepristone(less than 25 mg) were probably more effective than levonorgestrel (1.5 mg). Mifepristone low dose (less than 25 mg) was less effective than mid-dose mifepristone. UPA may be more effective than levonorgestrel.Levonorgestrel users had fewer side effects than Yuzpe users, and appeared to be more likely to have a menstrual return before the expected date. UPA users were probably more likely to have a menstrual return after the expected date. Menstrual delay was probably the main adverse effect of mifepristone and seemed to be dose-related. Cu-IUD may be associated with higher risks of abdominal pain than ECPs.

Clinical Pharmacology of Hormonal Emergency Contraceptive Pills

Emergency contraceptives play a major role in preventing unwanted pregnancy. The use of emergency contraceptives is characterized by myths and lack of knowledge by both health professionals and users. The main objective of this paper is to summarize the clinical pharmacology of hormonal methods of emergency contraception. A literature review was done to describe in detail the mechanism of action, efficacy, pharmacokinetics, safety profile, and drug interactions of hormonal emergency contraceptive pills. This information is useful to healthcare professionals and users to fully understand how hormonal emergency contraceptive methods work.

Sexual violence against women and care in the health sector in Santa Catarina - Brazil

This is a study on sexual violence against women in the Brazilian State of Santa Catarina notified to the Notifiable Diseases Information System (SINAN) in the period 20082013. It aimed to estimate pregnancy and sexually transmitted infections (STIs) resulting from sexual violence and to test the association between pregnancy, STIs and care provided in health services. In total, 1,230 pregnancy notifications and 1.316 STI notifications were analyzed. Variables were age, schooling, time to receive care, STI prophylaxis, emergency contraception, number of perpetrators and recurrent violence, which were analyzed using proportions and 95% confidence intervals. Associations were tested by adjusted and non-adjusted logistic regression with values expressed in odds ratio. The occurrence of pregnancy was 7.6%. Receiving care within 72 hours and emergency contraception were protective factors. The occurrence of STIs was 3.5%. Care within 72 hours and prophylaxis did not result in lower proportions of STIs. Further studies are required regarding this issue.

Safety Profile of Levonorgestrel: A Disproportionality Analysis of Food and Drug Administration Adverse Event Reporting System (Faers) Database

BACKGROUND

Levonorgestrel is most commonly utilized as an emergency oral contraceptive. Little is known and/or studied about the adverse effects of levonorgestrel, therefore, current investigation was aimed to generate signal for unreported adverse drug reactions of levonorgestrel using disproportionality analysis in food and drug administration adverse events reporting system database.

METHODS

In FDA Adverse Events Reporting System (FAERS) database, all adverse event reports for levonorgestrel between January 2006 to June 2015 were identified and disproportionality analysis was conducted for selected adverse events of levonorgestrel using Reporting Odds Ratio, Proportional Reporting Ratio and Information Component with 95% confidence interval.

RESULTS

A disproportionality analysis was done for 15 adverse events of levonorgestrel; out of these, signal for 10 adverse events was found and among them menstruation delayed was reported maximum (1791), followed by pregnancy after post-coital contraception (942), breast tenderness (901), metrorrhagia (899), dysmenorrhea (822), menorrhagia (541), nipple disorder (141), breast enlargement (77), ectopic pregnancy (61) and premenstrual syndrome (35). Pregnancy after post-coital contraception showed the highest signal having the Information Component value of 129.2, Reporting Odds Ratio value of 6.51 and Proportional Reporting Ratio value of 6.49.

CONCLUSION

In this paper, ten novel AEs were identified that were disproportionately reported with the use of LNG by using data mining techniques. Although a causal relationship cannot be established, the number of cases reported suggests that there might be an association. If confirmed by epidemiologic studies, the findings from this study would have potential implications for the use of LNG and patient management in clinical practice.

Prevalência e fatores associados da violência sexual contra a mulher: revisão sistemática

La revisión se propuso identificar en la literatura la prevalencia y factores asociados con la violencia sexual (VS) contra las mujeres adolescentes y adultas. Se revisaron estudios poblacionales, publicados entre 2011 y 2016, en inglés, portugués y español, en las bases de datos PubMed/Medline, Lilacs y SciELO. Los estudios fueron descritos y analizados, detallando sus características e informaciones sobre prevalencia y factores asociados a la VS. Entre los 3 002 artículos encontrados, de acuerdo con los criterios de inclusión, 15 estudios fueron objetos de esta revisión. La mayoría de los estudios se concentran en Asia y África, que también presentan las mayores prevalencias de VS. El grupo de edad predominante fue de 15 a 49 años. Se observó una gran variación de la prevalencia de VS entre los países. Con respecto a la VS cometida por una persona íntima, ésta varió del 1 % en Alemania al 92 % en Zimbabue. En cuanto a los factores asociados, se destacan la baja escolaridad, la juventud, las condiciones de salud mental y la salud sexual y reproductiva, así como el uso de alcohol y otras drogas. La revisión muestra la necesidad de profundizar en estudios sobre la violencia sexual, para contribuir a las políticas públicas, a detener la violencia contra las mujeres y la equidad de género.

Interventions for emergency contraception

BACKGROUND

Emergency contraception (EC) is using a drug or copper intrauterine device (Cu-IUD) to prevent pregnancy shortly after unprotected intercourse. Several interventions are available for EC. Information on the comparative effectiveness, safety and convenience of these methods is crucial for reproductive healthcare providers and the women they serve. This is an update of a review previously published in 2009 and 2012.

OBJECTIVES

To determine which EC method following unprotected intercourse is the most effective, safe and convenient to prevent pregnancy.

SEARCH METHODS

In February 2017 we searched CENTRAL, MEDLINE, Embase, PsycINFO, CINAHL, Popline and PubMed, The Chinese biomedical databases and UNDP/UNFPA/WHO/World Bank Special Programme on Human Reproduction (HRP) emergency contraception database. We also searched ICTRP and ClinicalTrials.gov as well as contacting content experts and pharmaceutical companies, and searching reference lists of appropriate papers.

SELECTION CRITERIA

Randomised controlled trials including women attending services for EC following a single act of unprotected intercourse were eligible.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures recommended by Cochrane. The primary review outcome was observed number of pregnancies. Side effects and changes of menses were secondary outcomes.

MAIN RESULTS

We included 115 trials with 60,479 women in this review. The quality of the evidence for the primary outcome ranged from moderate to high, and for other outcomes ranged from very low to high. The main limitations were risk of bias (associated with poor reporting of methods), imprecision and inconsistency. Comparative effectiveness of different emergency contraceptive pills (ECP)Levonorgestrel was associated with fewer pregnancies than Yuzpe (estradiol-levonorgestrel combination) (RR 0.57, 95% CI 0.39 to 0.84, 6 RCTs, n = 4750, I2 = 23%, high-quality evidence). This suggests that if the chance of pregnancy using Yuzpe is assumed to be 29 women per 1000, the chance of pregnancy using levonorgestrel would be between 11 and 24 women per 1000.Mifepristone (all doses) was associated with fewer pregnancies than Yuzpe (RR 0.14, 95% CI 0.05 to 0.41, 3 RCTs, n = 2144, I2 = 0%, high-quality evidence). This suggests that if the chance of pregnancy following Yuzpe is assumed to be 25 women per 1000 women, the chance following mifepristone would be between 1 and 10 women per 1000.Both low-dose mifepristone (less than 25 mg) and mid-dose mifepristone (25 mg to 50 mg) were probably associated with fewer pregnancies than levonorgestrel (RR 0.72, 95% CI 0.52 to 0.99, 14 RCTs, n = 8752, I2 = 0%, high-quality evidence; RR 0.61, 95% CI 0.45 to 0.83, 27 RCTs, n = 6052, I2 = 0%, moderate-quality evidence; respectively). This suggests that if the chance of pregnancy following levonorgestrel is assumed to be 20 women per 1000, the chance of pregnancy following low-dose mifepristone would be between 10 and 20 women per 1000; and that if the chance of pregnancy following levonorgestrel is assumed to be 35 women per 1000, the chance of pregnancy following mid-dose mifepristone would be between 16 and 29 women per 1000.Ulipristal acetate (UPA) was associated with fewer pregnancies than levonorgestrel (RR 0.59; 95% CI 0.35 to 0.99, 2 RCTs, n = 3448, I2 = 0%, high-quality evidence). Comparative effectiveness of different ECP dosesIt was unclear whether there was any difference in pregnancy rate between single-dose levonorgestrel (1.5 mg) and the standard two-dose regimen (0.75 mg 12 hours apart) (RR 0.84, 95% CI 0.53 to 1.33, 3 RCTs, n = 6653, I2 = 0%, moderate-quality evidence).Mid-dose mifepristone was associated with fewer pregnancies than low-dose mifepristone (RR 0.73; 95% CI 0.55 to 0.97, 25 RCTs, n = 11,914, I2 = 0%, high-quality evidence). Comparative effectiveness of Cu-IUD versus mifepristoneThere was no conclusive evidence of a difference in the risk of pregnancy between the Cu-IUD and mifepristone (RR 0.33, 95% CI 0.04 to 2.74, 2 RCTs, n = 395, low-quality evidence). Adverse effectsNausea and vomiting were the main adverse effects associated with emergency contraception. There is probably a lower risk of nausea (RR 0.63, 95% CI 0.53 to 0.76, 3 RCTs, n = 2186 , I2 = 59%, moderate-quality evidence) or vomiting (RR 0.12, 95% CI 0.07 to 0.20, 3 RCTs, n = 2186, I2 = 0%, high-quality evidence) associated with mifepristone than with Yuzpe. levonorgestrel is probably associated with a lower risk of nausea (RR 0.40, 95% CI 0.36 to 0.44, 6 RCTs, n = 4750, I2 = 82%, moderate-quality evidence), or vomiting (RR 0.29, 95% CI 0.24 to 0.35, 5 RCTs, n = 3640, I2 = 78%, moderate-quality evidence) than Yuzpe. Levonorgestrel users were less likely to have any side effects than Yuzpe users (RR 0.80, 95% CI 0.75 to 0.86; 1 RCT, n = 1955, high-quality evidence). UPA users were more likely than levonorgestrel users to have resumption of menstruation after the expected date (RR 1.65, 95% CI 1.42 to 1.92, 2 RCTs, n = 3593, I2 = 0%, high-quality evidence). Menstrual delay was more common with mifepristone than with any other intervention and appeared to be dose-related. Cu-IUD may be associated with higher risks of abdominal pain than mifepristone (18 events in 95 women using Cu-IUD versus no events in 190 women using mifepristone, low-quality evidence).

AUTHORS' CONCLUSIONS

Levonorgestrel and mid-dose mifepristone (25 mg to 50 mg) were more effective than Yuzpe regimen. Both mid-dose (25 mg to 50 mg) and low-dose mifepristone(less than 25 mg) were probably more effective than levonorgestrel (1.5 mg). Mifepristone low dose (less than 25 mg) was less effective than mid-dose mifepristone. UPA was more effective than levonorgestrel.Levonorgestrel users had fewer side effects than Yuzpe users, and appeared to be more likely to have a menstrual return before the expected date. UPA users were probably more likely to have a menstrual return after the expected date. Menstrual delay was probably the main adverse effect of mifepristone and seemed to be dose-related. Cu-IUD may be associated with higher risks of abdominal pain than ECPs.