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Meta-Analysis
. 2019 Jan 20;1(1):CD001324.
doi: 10.1002/14651858.CD001324.pub6.

Interventions for emergency contraception

Jie Shen  1 , Yan Che, Emily Showell, Ke Chen, Linan Cheng
Affiliations
Meta-Analysis

Interventions for emergency contraception

Jie Shen et al. Cochrane Database Syst Rev. .

Abstract

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.

PubMed Disclaimer

Conflict of interest statement

JS: no conflicts of interest. YC: no conflicts of interest KC: no conflicts of interest LC: participated in emergency contraceptive trials included in this review (including Chen 2011). LC did not participate in selecting these studies, or extracting their data. LC has received travel costs and consulting fees from Regenex Pharmaceutical Corporation, China Resources Zizhu Pharmaceutical Co, and Bayer Pharma AG. ES: no conflicts of interest

Figures

1
1
Study flow diagram
2
2
Risk of bias graph: review authors' judgements about each risk of bias item presented as percentages across all included studies
3
3
Risk of bias summary: review authors' judgements about each risk of bias item for each included study
4
4
Forest plot of comparison 2.1: levonorgestrel versus Yuzpe, outcome 2.1.1 Observed number of pregnancies (all women)
5
5
Funnel plot of comparison 2.4: Low‐dose mifepristone (< 25 mg) versus levonorgestrel 1.5 mg, outcome 2.4.1 Observed number of pregnancies (all women)
6
6
Forest plot of comparison 2.4: Low‐dose mifepristone (< 25 mg) versus levonorgestrel 1.5 mg, outcome 2.4.1 ITT (all loss follow‐up as pregnancy in levonorgestrel, and no pregnancy in mifepristone)
1.1
1.1. Analysis
Comparison 1 Intrauterine contraceptive device versus control (expectant management), Outcome 1 Observed number of pregnancies.
2.1
2.1. Analysis
Comparison 2 Levonorgestrel versus Yuzpe, Outcome 1 Observed number of pregnancies (all women).
2.2
2.2. Analysis
Comparison 2 Levonorgestrel versus Yuzpe, Outcome 2 Observed number of pregnancies (by risk status).
2.3
2.3. Analysis
Comparison 2 Levonorgestrel versus Yuzpe, Outcome 3 Observed number of pregnancies (time from intercourse).
2.4
2.4. Analysis
Comparison 2 Levonorgestrel versus Yuzpe, Outcome 4 Need for extra dose.
2.5
2.5. Analysis
Comparison 2 Levonorgestrel versus Yuzpe, Outcome 5 Any side effect.
2.6
2.6. Analysis
Comparison 2 Levonorgestrel versus Yuzpe, Outcome 6 Specific side effects.
2.7
2.7. Analysis
Comparison 2 Levonorgestrel versus Yuzpe, Outcome 7 Menses.
3.1
3.1. Analysis
Comparison 3 Levonorgestrel (all doses) versus anordrin (all doses), Outcome 1 Observed number of pregnancies (all women).
3.2
3.2. Analysis
Comparison 3 Levonorgestrel (all doses) versus anordrin (all doses), Outcome 2 Any side effect.
4.1
4.1. Analysis
Comparison 4 Mifepristone mid‐dose (25 mg‐50 mg) versus levonorgestrel 1.5 mg, Outcome 1 Observed number of pregnancies (all women).
4.2
4.2. Analysis
Comparison 4 Mifepristone mid‐dose (25 mg‐50 mg) versus levonorgestrel 1.5 mg, Outcome 2 Observed number of pregnancies (by risk status).
4.3
4.3. Analysis
Comparison 4 Mifepristone mid‐dose (25 mg‐50 mg) versus levonorgestrel 1.5 mg, Outcome 3 Any side effect.
4.4
4.4. Analysis
Comparison 4 Mifepristone mid‐dose (25 mg‐50 mg) versus levonorgestrel 1.5 mg, Outcome 4 Specific side effect.
4.5
4.5. Analysis
Comparison 4 Mifepristone mid‐dose (25 mg‐50 mg) versus levonorgestrel 1.5 mg, Outcome 5 Menses.
4.6
4.6. Analysis
Comparison 4 Mifepristone mid‐dose (25 mg‐50 mg) versus levonorgestrel 1.5 mg, Outcome 6 ITT (all loss follow‐up as pregnancy in LNG, and no preg in Mife).
4.7
4.7. Analysis
Comparison 4 Mifepristone mid‐dose (25 mg‐50 mg) versus levonorgestrel 1.5 mg, Outcome 7 ITT (all loss follow‐up as no pregnancy in LNG, and preg in Mife).
5.1
5.1. Analysis
Comparison 5 Mifepristone low dose (< 25 mg) versus levonorgestrel 1.5 mg, Outcome 1 Observed number of pregnancies (all women).
5.2
5.2. Analysis
Comparison 5 Mifepristone low dose (< 25 mg) versus levonorgestrel 1.5 mg, Outcome 2 Observed number of pregnancies (by risk status).
5.3
5.3. Analysis
Comparison 5 Mifepristone low dose (< 25 mg) versus levonorgestrel 1.5 mg, Outcome 3 Observed number of pregnancies (time from intercourse).
5.4
5.4. Analysis
Comparison 5 Mifepristone low dose (< 25 mg) versus levonorgestrel 1.5 mg, Outcome 4 Any side effect.
5.5
5.5. Analysis
Comparison 5 Mifepristone low dose (< 25 mg) versus levonorgestrel 1.5 mg, Outcome 5 Specific side effect.
5.6
5.6. Analysis
Comparison 5 Mifepristone low dose (< 25 mg) versus levonorgestrel 1.5 mg, Outcome 6 Menses.
5.7
5.7. Analysis
Comparison 5 Mifepristone low dose (< 25 mg) versus levonorgestrel 1.5 mg, Outcome 7 ITT (all loss follow‐up as pregnancy in LNG, and no preg in Mifepristone).
5.8
5.8. Analysis
Comparison 5 Mifepristone low dose (< 25 mg) versus levonorgestrel 1.5 mg, Outcome 8 ITT (all loss follow‐up as no pregnancy in LNG, and preg in Mifepristone).
6.1
6.1. Analysis
Comparison 6 Mifepristone (all doses) versus Yuzpe, Outcome 1 Observed number of pregnancies (all women).
6.2
6.2. Analysis
Comparison 6 Mifepristone (all doses) versus Yuzpe, Outcome 2 Observed number of pregnancies (by risk status).
6.3
6.3. Analysis
Comparison 6 Mifepristone (all doses) versus Yuzpe, Outcome 3 Observed number of pregnancies (time from intercourse).
6.4
6.4. Analysis
Comparison 6 Mifepristone (all doses) versus Yuzpe, Outcome 4 Need for extra dose.
6.5
6.5. Analysis
Comparison 6 Mifepristone (all doses) versus Yuzpe, Outcome 5 Any side effect.
6.6
6.6. Analysis
Comparison 6 Mifepristone (all doses) versus Yuzpe, Outcome 6 Specific side effects.
6.7
6.7. Analysis
Comparison 6 Mifepristone (all doses) versus Yuzpe, Outcome 7 Menses.
7.1
7.1. Analysis
Comparison 7 Mifepristone (all doses) versus anordrin (all doses), Outcome 1 Observed number of pregnancies (all women).
7.2
7.2. Analysis
Comparison 7 Mifepristone (all doses) versus anordrin (all doses), Outcome 2 Any side effect.
7.3
7.3. Analysis
Comparison 7 Mifepristone (all doses) versus anordrin (all doses), Outcome 3 Specific side effects.
7.4
7.4. Analysis
Comparison 7 Mifepristone (all doses) versus anordrin (all doses), Outcome 4 Menses.
8.1
8.1. Analysis
Comparison 8 Mifepristone alone (low or mid dose) versus mifepristone + anordrin (all doses), Outcome 1 Observed number of pregnancies (all women).
8.2
8.2. Analysis
Comparison 8 Mifepristone alone (low or mid dose) versus mifepristone + anordrin (all doses), Outcome 2 Any side effect.
8.3
8.3. Analysis
Comparison 8 Mifepristone alone (low or mid dose) versus mifepristone + anordrin (all doses), Outcome 3 Specific side effects.
8.4
8.4. Analysis
Comparison 8 Mifepristone alone (low or mid dose) versus mifepristone + anordrin (all doses), Outcome 4 Delay in menses.
9.1
9.1. Analysis
Comparison 9 Mifepristone versus mifepristone + misoprostol (all doses), Outcome 1 Observed number of pregnancies (all women).
9.2
9.2. Analysis
Comparison 9 Mifepristone versus mifepristone + misoprostol (all doses), Outcome 2 Specific side effect.
10.1
10.1. Analysis
Comparison 10 Mifepristone alone (all doses) versus mifepristone + tamoxifen (all doses), Outcome 1 Observed number of pregnancies (all women).
10.2
10.2. Analysis
Comparison 10 Mifepristone alone (all doses) versus mifepristone + tamoxifen (all doses), Outcome 2 Specific side effect.
10.3
10.3. Analysis
Comparison 10 Mifepristone alone (all doses) versus mifepristone + tamoxifen (all doses), Outcome 3 Menses.
11.1
11.1. Analysis
Comparison 11 Mifepristone alone (all doses) versus mifepristone + methotrexate (all doses), Outcome 1 Observed number of pregnancy (all women).
11.2
11.2. Analysis
Comparison 11 Mifepristone alone (all doses) versus mifepristone + methotrexate (all doses), Outcome 2 Any side effect.
11.3
11.3. Analysis
Comparison 11 Mifepristone alone (all doses) versus mifepristone + methotrexate (all doses), Outcome 3 Menses.
12.1
12.1. Analysis
Comparison 12 Mifepristone (all doses) versus danazol (all doses), Outcome 1 Observed number of pregnancies (all women).
12.2
12.2. Analysis
Comparison 12 Mifepristone (all doses) versus danazol (all doses), Outcome 2 Any side effect.
12.3
12.3. Analysis
Comparison 12 Mifepristone (all doses) versus danazol (all doses), Outcome 3 Specific side effect.
12.4
12.4. Analysis
Comparison 12 Mifepristone (all doses) versus danazol (all doses), Outcome 4 Menses.
13.1
13.1. Analysis
Comparison 13 Mifepristone versus gestrinone, Outcome 1 Observed number of pregnancies (all women).
13.2
13.2. Analysis
Comparison 13 Mifepristone versus gestrinone, Outcome 2 Side effects.
13.3
13.3. Analysis
Comparison 13 Mifepristone versus gestrinone, Outcome 3 Menses.
14.1
14.1. Analysis
Comparison 14 High‐dose oestrogens versus Yuzpe, Outcome 1 Observed number of pregnancies (all women).
15.1
15.1. Analysis
Comparison 15 Danazol (all doses) versus Yuzpe, Outcome 1 Observed number of pregnancies (all women).
15.2
15.2. Analysis
Comparison 15 Danazol (all doses) versus Yuzpe, Outcome 2 Specific side effects.
15.3
15.3. Analysis
Comparison 15 Danazol (all doses) versus Yuzpe, Outcome 3 Menses.
16.1
16.1. Analysis
Comparison 16 Ulipristal acetate (all doses) versus levonorgestrel, Outcome 1 Observed number of pregnancies (all women).
16.2
16.2. Analysis
Comparison 16 Ulipristal acetate (all doses) versus levonorgestrel, Outcome 2 Observed number of pregnancies (by risk status).
16.3
16.3. Analysis
Comparison 16 Ulipristal acetate (all doses) versus levonorgestrel, Outcome 3 Observed number of pregnancies (time from intercourse).
16.4
16.4. Analysis
Comparison 16 Ulipristal acetate (all doses) versus levonorgestrel, Outcome 4 Observed number of pregnancies within 0‐72 h.
16.5
16.5. Analysis
Comparison 16 Ulipristal acetate (all doses) versus levonorgestrel, Outcome 5 Specific side effects.
16.6
16.6. Analysis
Comparison 16 Ulipristal acetate (all doses) versus levonorgestrel, Outcome 6 Menses.
17.1
17.1. Analysis
Comparison 17 Levonorgestrel split dose, 24 hours versus 12 hours, Outcome 1 Observed number of pregnancy (all women).
17.2
17.2. Analysis
Comparison 17 Levonorgestrel split dose, 24 hours versus 12 hours, Outcome 2 Observed number of pregnancies (by risk status).
17.3
17.3. Analysis
Comparison 17 Levonorgestrel split dose, 24 hours versus 12 hours, Outcome 3 Specific side effects.
17.4
17.4. Analysis
Comparison 17 Levonorgestrel split dose, 24 hours versus 12 hours, Outcome 4 Menses.
18.1
18.1. Analysis
Comparison 18 Levonorgestrel single dose versus split dose, Outcome 1 Observed number of pregnancies (all women).
18.2
18.2. Analysis
Comparison 18 Levonorgestrel single dose versus split dose, Outcome 2 Observed number of pregnancies (by risk status).
18.3
18.3. Analysis
Comparison 18 Levonorgestrel single dose versus split dose, Outcome 3 Observed number of pregnancies (time from intercourse).
18.4
18.4. Analysis
Comparison 18 Levonorgestrel single dose versus split dose, Outcome 4 Specific side effects.
18.5
18.5. Analysis
Comparison 18 Levonorgestrel single dose versus split dose, Outcome 5 Menses.
19.1
19.1. Analysis
Comparison 19 Mifepristone low dose (10 mg) versus low dose (5 mg), Outcome 1 Observed number of pregnancies (all women).
19.2
19.2. Analysis
Comparison 19 Mifepristone low dose (10 mg) versus low dose (5 mg), Outcome 2 Specific side effects.
19.3
19.3. Analysis
Comparison 19 Mifepristone low dose (10 mg) versus low dose (5 mg), Outcome 3 Delay of menses.
20.1
20.1. Analysis
Comparison 20 Low dose mifepristone (10 mg) versus split low dose mifepristone (10 mg x2), Outcome 1 Observed number of pregnancies (all women).
20.2
20.2. Analysis
Comparison 20 Low dose mifepristone (10 mg) versus split low dose mifepristone (10 mg x2), Outcome 2 Any side effect.
20.3
20.3. Analysis
Comparison 20 Low dose mifepristone (10 mg) versus split low dose mifepristone (10 mg x2), Outcome 3 Menses.
21.1
21.1. Analysis
Comparison 21 Mifepristone mid dose (25‐50 mg) versus mifepristone low dose (< 25 mg), Outcome 1 Observed number of pregnancies (all women).
21.2
21.2. Analysis
Comparison 21 Mifepristone mid dose (25‐50 mg) versus mifepristone low dose (< 25 mg), Outcome 2 Observed number of pregnancies (by risk status).
21.3
21.3. Analysis
Comparison 21 Mifepristone mid dose (25‐50 mg) versus mifepristone low dose (< 25 mg), Outcome 3 Any side effect.
21.4
21.4. Analysis
Comparison 21 Mifepristone mid dose (25‐50 mg) versus mifepristone low dose (< 25 mg), Outcome 4 Specific side effects.
21.5
21.5. Analysis
Comparison 21 Mifepristone mid dose (25‐50 mg) versus mifepristone low dose (< 25 mg), Outcome 5 Menses.
22.1
22.1. Analysis
Comparison 22 Mifepristone mid dose (50 mg) versus mifepristone mid dose (25 mg), Outcome 1 Observed number of pregnancies (all women).
22.2
22.2. Analysis
Comparison 22 Mifepristone mid dose (50 mg) versus mifepristone mid dose (25 mg), Outcome 2 Any side effect.
22.3
22.3. Analysis
Comparison 22 Mifepristone mid dose (50 mg) versus mifepristone mid dose (25 mg), Outcome 3 Specific side effects.
22.4
22.4. Analysis
Comparison 22 Mifepristone mid dose (50 mg) versus mifepristone mid dose (25 mg), Outcome 4 Delay in menses.
23.1
23.1. Analysis
Comparison 23 Mid dose mifepristone split dose comparisons, Outcome 1 Observed number of pregnancies (all women).
23.2
23.2. Analysis
Comparison 23 Mid dose mifepristone split dose comparisons, Outcome 2 Any side effect.
23.3
23.3. Analysis
Comparison 23 Mid dose mifepristone split dose comparisons, Outcome 3 Early menses.
23.4
23.4. Analysis
Comparison 23 Mid dose mifepristone split dose comparisons, Outcome 4 Delay menses.
24.1
24.1. Analysis
Comparison 24 Mifepristone high dose (> 50 mg) versus mifepristone low dose (< 25 mg), Outcome 1 Observed number of pregnancies (all women).
24.2
24.2. Analysis
Comparison 24 Mifepristone high dose (> 50 mg) versus mifepristone low dose (< 25 mg), Outcome 2 Observed number of pregnancies (by risk status).
24.3
24.3. Analysis
Comparison 24 Mifepristone high dose (> 50 mg) versus mifepristone low dose (< 25 mg), Outcome 3 Any side effect.
24.4
24.4. Analysis
Comparison 24 Mifepristone high dose (> 50 mg) versus mifepristone low dose (< 25 mg), Outcome 4 Specific side effects.
24.5
24.5. Analysis
Comparison 24 Mifepristone high dose (> 50 mg) versus mifepristone low dose (< 25 mg), Outcome 5 Menses.
25.1
25.1. Analysis
Comparison 25 Mifepristone high dose (> 50 mg) versus mifepristone mid dose (25‐50 mg), Outcome 1 Observed number of pregnancies (all women).
25.2
25.2. Analysis
Comparison 25 Mifepristone high dose (> 50 mg) versus mifepristone mid dose (25‐50 mg), Outcome 2 Any side effect.
25.3
25.3. Analysis
Comparison 25 Mifepristone high dose (> 50 mg) versus mifepristone mid dose (25‐50 mg), Outcome 3 Specific side effects.
25.4
25.4. Analysis
Comparison 25 Mifepristone high dose (> 50 mg) versus mifepristone mid dose (25‐50 mg), Outcome 4 Menses.
26.1
26.1. Analysis
Comparison 26 Half‐dose Yuzpe versus standard Yuzpe, Outcome 1 Observed number of pregnancies (all women).
26.2
26.2. Analysis
Comparison 26 Half‐dose Yuzpe versus standard Yuzpe, Outcome 2 Any side effect.
26.3
26.3. Analysis
Comparison 26 Half‐dose Yuzpe versus standard Yuzpe, Outcome 3 Specific side effects.
27.1
27.1. Analysis
Comparison 27 Copper intrauterine device versus mifepristone (all doses), Outcome 1 Observed number of pregnancies (all women).
27.2
27.2. Analysis
Comparison 27 Copper intrauterine device versus mifepristone (all doses), Outcome 2 Any side effect.
27.3
27.3. Analysis
Comparison 27 Copper intrauterine device versus mifepristone (all doses), Outcome 3 Specific side effects.
27.4
27.4. Analysis
Comparison 27 Copper intrauterine device versus mifepristone (all doses), Outcome 4 Menses.
28.1
28.1. Analysis
Comparison 28 Time elapsed since intercourse in levonorgestrel, Outcome 1 ≤ 24 h vs > 24‐48 h.
28.2
28.2. Analysis
Comparison 28 Time elapsed since intercourse in levonorgestrel, Outcome 2 ≤ 24 h vs > 48‐72 h.
28.3
28.3. Analysis
Comparison 28 Time elapsed since intercourse in levonorgestrel, Outcome 3 > 24‐48 h vs > 48‐72 h.
28.4
28.4. Analysis
Comparison 28 Time elapsed since intercourse in levonorgestrel, Outcome 4 < 72 h vs > 72 h.
29.1
29.1. Analysis
Comparison 29 Time elapsed since intercourse (coitus‐treatment interval) in mifepristone, Outcome 1 ≤ 24 h vs > 24‐48 h.
29.2
29.2. Analysis
Comparison 29 Time elapsed since intercourse (coitus‐treatment interval) in mifepristone, Outcome 2 ≤ 24 h vs > 48‐72 h.
29.3
29.3. Analysis
Comparison 29 Time elapsed since intercourse (coitus‐treatment interval) in mifepristone, Outcome 3 > 24‐48 h vs > 48‐72 h.
29.4
29.4. Analysis
Comparison 29 Time elapsed since intercourse (coitus‐treatment interval) in mifepristone, Outcome 4 < 72 h vs > 72 h.
30.1
30.1. Analysis
Comparison 30 Time elapsed since intercourse in Yuzpe, Outcome 1 ≤ 24 h vs > 24‐48 h.
30.2
30.2. Analysis
Comparison 30 Time elapsed since intercourse in Yuzpe, Outcome 2 ≤ 24 h vs > 48‐72 h.
30.3
30.3. Analysis
Comparison 30 Time elapsed since intercourse in Yuzpe, Outcome 3 > 24‐48 h vs > 48‐72 h.
31.1
31.1. Analysis
Comparison 31 Time elapsed since intercourse in ulipristal acetate, Outcome 1 ≤ 24 h vs > 24‐48 h.
31.2
31.2. Analysis
Comparison 31 Time elapsed since intercourse in ulipristal acetate, Outcome 2 ≤ 24 h vs > 48‐72 h.
31.3
31.3. Analysis
Comparison 31 Time elapsed since intercourse in ulipristal acetate, Outcome 3 > 24‐48 h vs > 48‐72 h.
31.4
31.4. Analysis
Comparison 31 Time elapsed since intercourse in ulipristal acetate, Outcome 4 < 72 h vs > 72 h.
32.1
32.1. Analysis
Comparison 32 High‐risk women versus low‐risk women (all hormonal methods), Outcome 1 Observed number of pregnancies.
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References

References to studies included in this review

Arowojolu 2002 {published data only}
    1. Arowojolu AO, Okewole LA, Adekunle AO. Comparative evaluation of the effectiveness and safety of two regimens of levonorgestrel for emergency contraception in Nigerians. Contraception 2002;66:269‐73. - PubMed
Ashok 2002 {published data only}
    1. Ashok PW, Stalder C, Wagaarachchi PT, Flett GM, Melvin L, Templeton A. A randomised study comparing a low dose of mifepristone and the Yuzpe regimen for emergency contraception. BJOG 2002;109:553‐60. - PubMed
Askalani 1987 {published data only}
    1. Askalani AH, Al‐Senity AM, Al‐Agizy HM, Salam HI, Al‐Masry GI, El‐Sadek SM. Evaluation of copper T‐200 as a post‐coital contraceptive. Egyptian Journal of Obstetrics and Gynaecology 1987;13:63‐6.
Bu 2006 {published data only (unpublished sought but not used)}
    1. Bu GY, Yang MY, Cao XL. Clinical study on administration of low dose of mifepristone and levonorgestrel in urgent postcoital contraception [小剂量米非司酮和左炔诺孕酮用于紧急避孕的临床研究]. Progress in Modern Biomedicine 2006;6(2):53‐4.
Cao 1999 {published data only}
    1. Cao P, Li M, Xu J, Li Q. Different doses of mifepristone for emergency contraception [不同剂量米非司酮用于紧急避孕效果的观察与分析]. Journal of Practical Obstetrics and Gynecology 1999;15:295‐6.
Cao 2011 {published data only}
    1. Cao YQ, Yang AH, Zhu XL. A comparative clinical study on mifepristone with levonorgestrel for emergency contraception [米非司酮和左炔诺孕酮在紧急避孕中的临床研究]. Chinese Journal of General Practice 2011;9(7):1087‐8.
Carbonell 2015 {published data only}
    1. Carbonell JL, Garcia R, Gonzalez A. Mifepristone 5 mg versus 10 mg for emergency contraception: double‐blinded randomized clinical trial. International Journal of Women's Health 2015;7:95‐102. - PMC - PubMed
Chen 2001 {published data only}
    1. Chen G. Mifepristone for emergency contraception [米非司酮用于紧急避孕的临床观察]. Journal of Guangxi Traditional Chinese Medical University 2001;4:22‐4.
Chen 2002a {published data only}
    1. Chen R, Li Q, Zhang Y, Huang M, Chen Y, Zhong X, et al. A comparative study of low‐dose mifepristone for emergency contraception [两种不同小剂量米非司酮用于紧急避孕的临床研究]. Shi Yong Yi Xue Zha Zi 2002;10:1028‐9.
Chen 2002b {published data only}
    1. Chen H, Min X. Mifepristone in combination with MTX for emergency contraception [米非司酮加用氨甲喋呤用于紧急避孕的研究]. Strait Pharmaceutical Journal 2002;3:51‐2.
Chen 2008 {published data only}
    1. Chen Y. A comparative study of mifepristone and LNG for emergency contraception [米非司酮、左炔诺孕酮用于紧急避孕的临床效果对比性观察]. China Foreign Medical Treatment 2008;34:60.
Chen 2009 {published data only}
    1. Chen S, An HB, Wang D, Jin FB. Different dose of mifepristone for emergency contraception [不同剂量米非司酮用于紧急避孕的临床观察]. China Health Care Nutrition ‐ Clinical Medicine Journal 2009;2:28‐9.
Chen 2013 {published data only}
    1. Chen SJ, Wen CX, Huang CX. A comparative study on mifepristone with levonorgestrel for emergency contraception [左炔诺孕酮与米非司酮用于紧急避孕的效果比较]. Chinese Journal of Ethnomedicine and Ethnopharmacy 2013;10:105.
Chen 2015 {published data only}
    1. Chen CX. A comparative study on mifepristone with levonorgestrel for emergency contraception [米非司酮与左炔诺孕酮用于紧急避孕临床对比研究]. Medical Forums in Basic 2015;8:1024‐5.
Cheng 1999a {published data only}
    1. Cheng L, Tong CH, Xiao ZH. Low doses of mifepristone for emergency postcoital contraception [不同剂量米非司酮用于紧急避孕的临床多中心研究]. Chinese Journal of Obstetrics and Gynaecology 1999;6:335‐8.
Cheng 2009 {published data only}
    1. Cheng S. Clinical observation on YUTING for emergency contraception [毓婷预防早孕的临床疗效观察]. Chinese Journal of Modern Drug Application 2009;8:147‐8.
Creinin 2006 {published data only}
    1. Creinin MD, Schlaff W, Archer DF, Wan L, Frezieres R, Tomas M, et al. Progesterone receptor modulator for emergency contraception. A randomized controlled trial. Obstetrics & Gynecology 2006;108:1089‐97. - PMC - PubMed
Dada 2010 {published data only}
    1. Dada OA, Godfrey EM, Piaggio G, Hertzen H, Nigerian Network for Reproductive Health Research and Training. A randomized, double‐blind, noninferiority study to compare two regimens of levonorgestrel for emergency contraception in Nigeria. Contraception 2010;82(4):373‐8. - PubMed
Ding 2005 {published data only}
    1. Ding G. Different doses of mifepristone for emergency contraception [不同剂量米非司酮用于紧急避孕的临床观察]. Journal of Practical Diagnosis and Therapy 2005;19:226‐7.
Dong 2009 {published data only}
    1. Dong JF. Two different methods for emergency contraception [两种不同方法用作紧急避孕的临床研究]. Practical Clinical Journal of Integrated Traditional Chinese and Western Medicine 2009;9(1):58‐9.
Du 2002 {published data only}
    1. Du J. Low dose of mifepristone for emergency contraception [小剂量米非司酮用于紧急避孕的临床观察]. Henan Yi Yao Xin Xi 2002;11:14‐5.
Ellertson 2003a {published data only}
    1. Ellertson C, Webb A, Blanchard K, Bigrigg A, Haskell S, Shochet T, et al. Modifying the Yuzpe regimen of emergency contraception: a multicenter randomized controlled trial. Obstetrics and Gynecology 2003;101:1160‐7. - PubMed
Fan 2001a {published data only}
    1. Fan H, Cheng Y, Guo F, Wu S, Tan Y, Chen X, et al. Low dose of mifepristone for emergency contraception. Hubei Yu Fang Yi Xue Zha Zi 2001;23:52.
Fang 2000 {published data only}
    1. Fang Q, Guo X, Pan J, Xiao J, Li Y. A comparative study on different doses of mifepristone for emergency contraception [不同剂量米非司酮用于紧急避孕的临床观察]. Maternal and Child Health Care of China 2000;15:48‐9.
Farajkhoda 2009 {published data only}
    1. Farajkhoda T, Khoshbin A, Enjezab B, Bokaei M, Karimi Zarchi M. Assessment of two emergency contraceptive regimens in Iran: levonorgestrel versus the Yuzpe. Niger Journal of Clinical Practice 2009;12(4):450‐2. - PubMed
Fu 2000 {published data only}
    1. Fu X, Wang L, Jiang Q, Yang X. Anordrin and mifepristone for emergency contraception [双炔失碳酯或米非司酮用于紧急避孕临床观察]. Journal of Qinghai Medical College 2000;21:43‐4.
Gan 2007 {published data only}
    1. Gan XH, Jiang H, Li LP. A clinical study of low‐dose mifepristone for emergency contraception [小剂量米非司酮用于紧急避孕的临床观察]. Modern Medicine Health 2007;23(11):1634‐5.
Glasier 1992 {published and unpublished data}
    1. Glasier A, Thong KJ, Dewar M, Mackie M, Baird D. Postcoital contraception with mifepristone (letter). Lancet 1991;337:1414‐5. - PubMed
    1. Glasier A, Thong KJ, Dewar M, Mackie M, Baird DT. Mifepristone (RU 486) compared with high‐dose estrogen and progestogen for emergency postcoital contraception. New England Journal of Medicine 1992;327:1041‐4. - PubMed
Glasier 2010 {published data only}
    1. Glasier AF, Cameron ST, Fine PM, Logan SJ, Casale W, Horn J, et al. Ulipristal acetate versus levonorgestrel for emergency contraception: a randomised non‐inferiority trial and meta‐analysis. Lancet 2010;375(9714):555‐62. - PubMed
Hamoda 2004 {published data only}
    1. Hamoda H, Ashok PW, Stalder C, Flett GMM, Kennedy E, Templeton A. A randomized trial of mifepristone (10 mg) and levonorgestrel for emergency contraception. Obstetrics & Gynecology 2004;104:1307‐13. - PubMed
Han 1995 {published data only}
    1. Han X, Weng L, Zhang L, Zeng T, Xiao B. Clinical trial of mifepristone and anordrin for emergency contraception [米非司酮,双炔失碳酯单独或联合应用于紧急避孕的临床观察]. Journal of Reproductive Medicine (China) 1995;4:206‐11.
Han 1996 {published data only}
    1. Han X, Weng L, Xiao B. Emergency contraception with mifepristone and anordrin [米非司酮用于紧急避孕的临床观察]. Chinese Journal of Obstetrics and Gynecology 1996;9:526‐9. - PubMed
Han 1999a {published data only}
    1. Han X, Jin X, Weng L. A comparative study of mifepristone with levonorgestrel for emergency contraception [左炔诺孕酮或米非司酮用于紧急避孕的临床观察]. Journal of Practical Obstetrics and Gynecology 1999;6:294‐5.
Han 2001a {published data only}
    1. Han L, Ma Y, Li H. Low doses of mifepristone for emergency contraception [低剂量米非司酮用于紧急避孕]. Fudan University Journal of Medical Sciences 2001;2:176‐7.
He 2002 {published data only}
    1. He CH, Gui YL, Yang J, Wang BS, Zheng E, Gao ES, et al. A randomized comparative study on mifepristone alone and in combination with tamoxifen for emergency contraception. Contraception 2002;66:221‐4. - PubMed
Ho 1993 {published and unpublished data}
    1. Ho PC, Kwan MSW. A prospective randomized comparison of levonorgestrel with the Yuzpe regimen in post‐coital contraception. Human Reproduction 1993;8:389‐92. - PubMed
Hoseini 2013 {published data only}
    1. Hoseini FS, Eslami M, Abbasi M, Noroozi Fashkhami F, Besharati S. A randomized, controlled trial of levonorgestrel vs. the Yuzpe regimen as emergency contraception method among Iranian women. Iranian Journal of Public Health 2013;42(10):1158‐66. - PMC - PubMed
Hu 2003 {published data only}
    1. Hu X, Lu C. A comparative study of mifepristone with levonorgestrel for emergency contraception [米非司酮、左炔诺孕酮用于紧急避孕的临床效果观察]. Sichuan Medical Journal 2003;24(8):F004.
Jin 2012 {published data only}
    1. Jin YC, Jin YY. A comparative study on efficiency and side effects of mifepristone with levonorgestrel for emergency contraception [毓婷与米非司酮在紧急避孕中的效果及不良反应分析]. Seek Medical and Ask the Medicine 2012;10(2):167‐8.
Lai 2004 {published data only}
    1. Lai Z, Wang J, Zhou Z, Lu H, Song X, Sun J. A comparative study of low‐dose mifepristone for emergency contraception [低剂量米非司酮用于紧急避孕的临床观察]. Maternal and Child Health Care of China 2004;19(2):36‐8.
Lan 2006 {published data only}
    1. Lan XL, Chen LP, Ye QH. Clinical study of low‐dose mifepristone for emergency contraception [小剂量米非司酮用于紧急避孕的临床观察]. Clinical Medicine 2006;26(11):68‐9.
Lei 2013 {published data only}
    1. Lei X, Yang G. A comparative observation on mifepristone with levonorgestrel for emergency contraception [米非司酮与左炔诺孕酮用于紧急避孕的效果比较]. Medical Information 2013;26(15):486.
Li 2000a {published data only}
    1. Li A, Zhang Y. Low dose of mifepristone for emergency contraception [小剂量米非司酮用于紧急避孕的疗效观察]. Journal of Guangxi Medical University 2000;17:857.
Li 2000b {published data only}
    1. Li Q, Chen R, Zhang Y, Huang M, Chen RX, Zhong X. A comparative study of mifepristone 50 mg and 25 mg for emergency contraception [50mg与25mg米非司酮用于紧急避孕的临床效果比较]. Guangdon Medical Journal 2000;22:884‐5.
Li 2000c {published data only}
    1. Li H, Chang JP, Li J. A study of low‐dose mifepristone for emergency contraception [小剂量米非司酮用于紧急避孕的临床观察]. Heilongjiang Medical Journal 2000;23:90.
Li 2002a {published data only}
    1. Li W. A comparative study of mifepristone with levonorgestrel for emergency contraception [米非司酮与左炔诺酮用于紧急避孕的临床效果观察]. Guizhou Journal of Medicine 2002;5:457.
Li 2005b {published data only}
    1. Li J. A comparative study of mifepristone with levonorgestrel for emergency contraception [米非司酮和左炔诺酮用于紧急避孕效果观察]. Anthology of Medicine 2005;5:754.
Liang 2001 {published data only}
    1. Liang JZ, Zhou MR. A randomised comparative study on mifepristone and levonorgestrel for emergency contraception [米非司酮和左炔诺孕酮在紧急避孕中的临床观察]. Heilongjiang Medical Journal 2001;25:594.
Liao 2003 {published data only}
    1. Liao AH, Chang CF, Zhu JW. Randomised controlled prospective studies of mifepristone in small doses and levonorgestrel for emergency contraception [小剂量米非司酮和左炔诺孕酮用于紧急避孕的随机对照研究]. Chinese Journal of Practical Gynaecology and Obstetrics 2003;19:25‐7.
Lin 2000 {published data only}
    1. Lin N, Cheng W, Yang Y, Shao L. A comparative study of mifepristone and LNG for emergency contraception [小剂量米非司酮与左旋18‐甲基炔诺酮单方用于紧急避孕的比较研究]. Tianjing Medical Journal 2000;28:601‐3.
Liu 2000 {published data only}
    1. Liu JL, Liu LH, Li KZ, Liu HL. Comparative study of the efficacy of low‐dose mifepristone and levonorgestrel on the emergency contraception [低剂量米非司酮与左旋18甲基炔谱酮紧急避孕临床效果观察]. Practical Preventive Medicine 2000;7:126‐7.
Liu 2001 {published data only}
    1. Liu L, Wang Z, Li L. Mifepristone and anordrin for emergency contraception [米非司酮、双炔失碳酯用于紧急避孕的临床观察]. Zhong Guo Yiu Sheng Yu Yi Chuan Zha Zi 2001;9:108‐11.
Liu 2002b {published data only}
    1. Liu L, Chen A. A comparative study of mifepristone with Cu‐IUD for emergency contraception [米非司酮与带铜宫内节育器（IUD）用于紧急避孕方法的对比观察]. Journal of Changzhi Medical College 2002;61:198‐9.
Liu 2009 {published data only}
    1. Liu RQ. A comparative study of mifepristone and LNG for emergency contraception [米非司酮和毓婷紧急避孕的有效性和安全性评价]. China Pharmaceuticals 2009;19:68‐9.
Lou 2002 {published data only}
    1. Lou C. Low‐dose mifepristone for emergency contraception [低剂量米非司酮用于紧急避孕的效果]. Xian Dai Shi Yong YI Xue 2002;14:485.
Lou 2005 {published data only}
    1. Lou X, Ma L, Yang Y. Mifepristone and C53 contraceptive in postcoital contraception [米非司酮与双炔失碳酯联合用于紧急避孕的临床观察]. Journal of Chinese Modern Gynaecology and Obstetrics 2005;2:405‐6.
Miras 2014 {published data only}
    1. Miras RG, Sanchez AG, Miras LG, Llibre Guerra JJ, Jesus Delgado González M, Penalver Cruz AM. Mifepristone efficacy for emergency contraception when comparing 5 and 10 milligrams doses [Eficacia de la mifepristona como comtraceptivo de emergencia al comparar dosis de 5 y 10 miligramos]. Revista Cubana de Obstetricia y Ginecologia 2014;40(3):326‐35.
Ngai 2005 {published data only}
    1. Ngai SW, Fan S, Li S, Cheng L, Ding J, Jing X, et al. A randomized trial to compare 24 h versus 12 h double dose regimen of levonorgestrel for emergency contraception. Human Reproduction 2005;20:307‐11. - PubMed
Pei 2001 {published data only}
    1. Pei JH, Wang ZX. A randomised comparative study of mifepristone in small doses and levonorgestrel for emergency contraception [小剂量米非司酮与左炔诺孕酮用于紧急避孕的临床观察]. Haerbin Medicine 2001;21:32‐3.
Qi 2000a {published data only}
    1. Qi Y, Zhang J, Cao Y, Zhang Z. A comparative clinical trial on two low doses of mifepristone for emergency contraception [两种低剂量米非司酮用于紧急避孕随机对比临床观察]. Maternal and Child Health Care of China 2000;15:701‐4.
Qi 2003 {published data only}
    1. Qi M, Wang Y, Yan L. A comparative study of low‐dose mifepristone with levonorgestrel for emergency contraception ‐ 288 cases report [小剂量米非司酮与左炔诺孕酮片紧急避孕288例观察]. Journal of Qinghai Medical College 2003;24:255‐6.
Qian 1999 {published data only}
    1. Qian L. Three doses of mifepristone for emergency contraception [三种剂量米非司酮用于紧急避孕的临床观察]. Chinese Journal of Family Planning 1999;7:322‐3.
Rowlands 1983 {published data only}
    1. Rowlands S, Guillebaud J, Bounds W, Booth M. Side effects of danazol compared with an ethinyloestradiol/norgestrel combination when used for postcoital contraception. Contraception 1983;27:39‐49. - PubMed
    1. Rowlands S, Kubba AA, Guillebaud J, Bounds W. A possible mechanism of action of danazol and an ethinylestradiol/norgestrel combination used as postcoital contraceptive agents. Contraception 1986;33:539‐45. - PubMed
Sang 1999 {published data only}
    1. Sang GW, Shao Q, Zhang J, Zhang M, Chen S, Song S, et al. A randomized multicentre clinical trial on different doses of mifepristone alone and in combination with anordrin as emergency contraception [不同剂量米非司酮及合并双炔失碳酯用于紧急避孕的多中心随机临床研究]. Chinese Journal of Obstetrics and Gynaecology 1999;34(6):331‐4. - PubMed
Shao 2010 {published data only}
    1. Shao XY. Clinical observation on mifepristone for emergency contraception [米非司酮用于紧急避孕的临床观察]. Practical Clinical Journal of Integrated Traditional Chinese and Western Medicine 2010;10(3):55.
Sheng 2002 {published data only}
    1. Sheng A. Clinical observation of the efficacy of mifepristone and levonorgestrel on the emergency contraception [小剂量米非司酮和左炔诺酮用于紧急避孕的疗效观察]. Academic Journal of Jiangsu University (Medicine) 2002;12:246‐9.
Sheng 2008 {published data only}
    1. Sheng SY. A clinical study of LNG‐COC for emergency contraception [复方左炔诺孕酮用于紧急避孕的临床观察]. Asia‐Pacific Traditional Medicine 2008;4(9):93‐4.
Su 2001 {published data only}
    1. Su W, Chui JY, Liu P. A comparative study of IUCD with mifepristone and with levonorgestrel for emergency contraception [米非司酮、 左炔诺孕酮和IUCD用于紧急避孕的临床观察研究]. Journal of Baotou Medicine 2001;25:24.
Sun 2000 {published data only}
    1. Sun Y, Wang X. A clinical comparative study of mifepristone with levonorgestrel for emergency contraception [米非司酮,左炔诺孕酮用于紧急避孕的临床效果观察]. Chinese Journal of Family Planning 2000;8:172‐3.
Sun 2003 {published data only}
    1. Sun P. Mifepristone for emergency contraception [米非司酮用于紧急避孕的研究]. Journal of Chinese Practice Medicine 2003;5:92.
Sun 2007 {published data only}
    1. Sun MX. A clinical comparative study of LNG vs. LNG‐COC for emergency contraception [左炔诺孕酮和复方短效避孕药用于紧急避孕的临床观察]. Chinese Journal of Family Planning 2007;15(6):366‐7.
Tan 1999 {published data only}
    1. Tan K, Mai T, He P, Lin H, Li S. Low doses of mifepristone for emergency contraception [分两次服用小剂量米非司酮用于紧急避孕]. Chinese Journal of Family Planning 1999;7:470‐1.
Tan 2003 {published data only}
    1. Tan L, Zheng G, Li J. Mifepristone for emergency contraception ‐ 150 cases report [150例米非司酮用于紧急避孕的临床观察]. Health Vocational Education 2003;21:138‐9.
Tao 2014 {published data only}
    1. Tao XL, Xiong J. A study on mifepristone for emergency contraception [复方米非司酮应用于紧急避孕150例]. Herald of Medicine 2014;33(6):742‐3.
Tian 2013 {published data only}
    1. Tian ZM. A clinical comparative observation among copper IUD and mifepristone for emergency contraception [Cu‐IUD和米非司酮用于紧急避孕的效果比较]. China Health Care & Nutrition 2013;9:5238.
Van Santen 1985a {published data only}
    1. Santen MR, Haspels AA. A comparison of high‐dose estrogens versus low‐dose ethinylestradiol and norgestrel combination in postcoital interception: a study in 493 women. Fertility and Sterility 1985;43:206‐13. - PubMed
    1. Santen MR, Haspels AA. Comparative randomized double‐blind study of high dosage ethinylestradiol versus ethinylestradiol and norgestrel combination in postcoital contraception. Acta Endocrinologica 1982;99(suppl 246):2.
von Hertzen 2002 {published data only}
    1. Hertzen H, Piaggio G, Ding J, Chen J, Song S, Bartfai G, et al. Low dose mifepristone and two regimens of levonorgestrel for emergency contraception. Lancet 2002;360:1803‐10. - PubMed
Wang 1999 {published data only}
    1. Wang Z, Liu L, Liu Q, Zhang H. A clinical comparative study of mifepristone with anordrin for emergency contraception [米非司酮,双炔失碳酯用于紧急避孕临床效果观察]. Chinese Journal of Family Planning 1999;7:320‐1.
Wang 2000a {published data only}
    1. Wang C, Tian M, Chang Y, Shao M. A clinical comparative observation among copper IUD, lower dose mifepristone and levonorgestrel for emergency contraception [含铜IUD、小剂量米非司酮与左炔诺孕酮用于紧急避孕的临床比较观察]. Journal of Chinese Physician 2000;2:271‐3.
Wang 2000b {published data only}
    1. Wang Q, Li A. A comparative study of levonorgestrel with low dose mifepristone for emergency contraception [左炔诺孕酮和小剂量米非司酮用于紧急避孕的临床观察]. Northwestern Pharmaceutical Journal 2000;15:72.
Wang 2001 {published data only}
    1. Wang SZ, Huang ZK, Li S. Clinical trial of mifepristone in different dose for emergency contraception [不同剂量米非司酮用于紧急避孕的临床比较观察]. Chinese Journal of Practical Gynaecology and Obstetrics 2001;9:534‐6.
Wang 2003 {published data only}
    1. Wang Y, Liu H. A comparative study on low doses of mifepristone with levonorgestrel for emergency contraception [左炔诺孕酮和小剂量米非司酮用于紧急避孕的临床观察]. Chinese Journal of Family Planning 2003;8:505‐6.
Wang 2004 {published data only}
    1. Wang L, Lv Y, Guan D, Zhang H, Yao L. 12.5 mg mifepristone for emergency contraception [12.5 mg 米非司酮用于紧急避孕的临床研究]. Chinese General Practice 2004;7:1477‐8.
Wang 2006a {published data only}
    1. Wang J. A comparative study on different doses of mifepristone for emergency contraception [不同剂量米非司酮用于紧急避孕的临床疗效研究]. Journal Huaihai Medicine 2006;24:19‐20.
Wang 2008 {published data only}
    1. Wang ZW, Qu HW. Two different doses of mifepristone for emergency contraception [两种剂量米非司酮进行紧急避孕比较分析]. Chinese Journal of Misdiagnosis 2008;20:4819‐20.
Wang 2012 {published data only}
    1. Wang CL. A comparative clinical study on mifepristone with levonorgestrel for emergency contraception [左炔诺孕酮和米非司酮用于紧急避孕的临床观察]. Guide of China Medicine 2012;10(5):102‐3.
Webb 1992 {published data only}
    1. Webb AM. Alternative treatments in oral postcoital contraception: interim results. Advances in Contraception 1991;7:271‐9. - PubMed
    1. Webb AMC, Russell J, Elstein M. Comparison of Yuzpe regimen, danazol, and mifepristone (RU486) in oral postcoital contraception. BMJ 1992;305:927‐31. - PMC - PubMed
Wei 2002a {published data only}
    1. Wei RH. Low dose of mifepristone for emergency contraception ‐ 200 cases report [小剂量米非司酮用于紧急避孕200例的临床观察]. Shanghai Sheng Wu Yi Xue Gong Cheng Zha Zi 2002;23:39‐42.
Wei 2011 {published data only}
    1. Wei H, He CB, Liu J. Low dose mifepristone for emergency contraception [小剂量米非司酮用于紧急避孕的临床研究]. Chinese and Foreign Women Health 2011;19(3):70.
WHO 1998 {published data only}
    1. WHO Task Force on Postovulatory Methods of Fertility Regulation. Randomised controlled trial of levonorgestrel versus the Yuzpe regimen of combined oral contraceptives for emergency contraception. Lancet 1998;352:428‐33. - PubMed
WHO 1999 {published data only}
    1. WHO Task Force on Postovulatory Methods of Fertility Regulation. Comparison of three single doses of mifepristone as emergency contraception: a randomised trial. Lancet 1999;353:697‐702. - PubMed
Wu 1999a {published data only}
    1. Wu S, Wang C, Wang Y, Cheng W, Zuo S, Li H, et al. A randomized, double‐blind, multicentre study on comparing levonorgestrel and mifepristone for emergency contraception [左炔诺孕酮和小剂量米非司酮用于紧急避孕的临床观察]. Chinese Journal of Obstetrics and Gynaecology 1999;34:327‐30. - PubMed
Wu 2002 {published data only}
    1. Wu XZ, Sao JY, Chen CQ, Yan Y, Fa YY, Liu JH, et al. A comparative study on methods for emergency contraception [两种紧急避孕方法比较性研究]. Reproduction & Contraception (China) 2002;22:152‐5.
Wu 2010 {published data only}
    1. Wu S, Dong J, Cong J, Wang CP, Hertzen H, Godfrey EM. Gestrinone compared with mifepristone for emergency contraception: a randomized controlled trial. Obstetrics and Gynecology 2010;115(4):740‐4. - PubMed
Xiao 2002 {published data only}
    1. Xiao BL, Hertzen H, Piaggio G. A randomized double‐blind comparison of two single doses of mifepristone for emergency contraception. Human Reproduction 2002;17:3084‐9. - PubMed
Xie 1998 {published data only}
    1. Xie X, Liu Y, Lin X. A clinical study on 600 cases of mifepristone for emergency contraception [米非司酮用于紧急避孕600例临床观察]. Reproduction & Contraception (China) 1998;18:224‐6.
Xie 2010 {published data only}
    1. Xie HH, Shang XM, Dai WY. Analysis of emergency contraception use mifepristone by different doses [不同剂量米非司酮用于紧急避孕的疗效分析]. Guide of China Medicine 2010;8(14):34‐5.
Xu 2000a {published data only}
    1. Xu Z. A comparative study of mifepristone, anordrin and levonorgestrel for emergency contraception [米非司酮、双炔失碳酯、左炔诺孕酮用于紧急避孕的临床观察]. Journal of Yichun Medical College 2000;12:248‐9.
Xu 2000b {published data only}
    1. Xu L, Wang Z. A comparative study on low dose mifepristone with levonorgestrel for emergency contraception [低剂量米非司酮、左炔诺孕酮用于紧急避孕的临床观察]. Chinese Journal of Family Planning 2000;8:419‐20.
Yang 2001 {published data only}
    1. Yang LJ. A comparative study on mifepristone, anordrin and danazol for emergency contraception [米非司酮双炔失碳酯丹那唑紧急避孕的临床研究]. Guangzhou Medical Journal 2001;32:12‐3.
Yang 2003 {published data only}
    1. Yang F. A comparative study on two low doses of mifepristone for emergency contraception. Journal of Clinical Research 2003;20:630‐1.
Ye 2013 {published data only}
    1. Ye LQ. A study on the effect of mifepristone for emergency contraception. For all Health 2013;7(1):12‐13.
Zeng 2007 {published data only}
    1. Zeng XY. A clinical study of Mifepristone in combination with MTX for emergency contraception. Practical Clinical Journal of Integrated Chinese and Western Medicine 2007;7(3):62‐3.
Zeng 2008 {published data only}
    1. Zeng MY, Zhu LF, Huang Y. A comparative study of low‐dose mifepristone for emergency contraception [小剂量米非司酮用于紧急避孕的临床观察]. International Medicine Health Guidance News 2008;14:68‐70.
Zhang 1998 {published data only}
    1. Zhang Y, Qiao G, Zhu P, Zhang S, Zhang J, Zhu N. Clinical observation of three lower doses of mifepristone for emergency contraception [三种低剂量米非司酮用于紧急避孕的临床观察]. Chinese Journal of Family Planning 1998;6:343‐5.
Zhang 1999b {published data only}
    1. Zhang X, Gao G, Shi J, Qu C, Leng Y. A clinical study on low doses of mifepristone for emergency contraception [低剂量米非司酮用于紧急避孕的临床效果观察]. Chinese Journal of Family Planning 1999;4:175‐6.
Zhang 2000 {published data only}
    1. Zhang JQ. Emergency contraception in high‐land [高原地区紧急避孕临床应用]. Chinese Journal of Family Planning 2000;8:552‐4.
Zhang 2002a {published data only}
    1. Zhang Y, Zhang W, Wang L. Low‐dose of mifepristone and anordrin for emergency contraception: observation of 116 cases [低剂量米非司酮并用双炔失碳酯用于紧急避孕116例分析]. Journal of Qiqihar Medical College 2002;4:415.
Zhang 2002b {published data only}
    1. Zhang Y, Wen L, Li S, Wang Y. Mifepristone for emergency contraception [米非司酮用于紧急避孕的临床研究]. Henan YI Yao Xin XI 2002;8:20‐1.
Zhang 2005 {published data only}
    1. Zhang L, Lai L, Deng X. Single and small dose of Mifepristone for emergency contraception of curative effect observe [单次小剂量米非司酮用于紧急避孕的疗效观察]. Journal of Gannan Medical College 2005;3:328‐30.
Zhang 2012 {published data only}
    1. Zhang H. A comparative clinical study on mifepristone with levonorgestrel for emergency contraception [左炔诺孕酮和米非司酮用于紧急避孕的临床观察]. Guide of China Medicine 2012;10(26):576‐7.
Zhang 2014 {published data only}
    1. Zhang LR. A comparative clinical study on mifepristone with levonorgestrel for emergency contraception [米非司酮与左炔诺孕酮用于紧急避孕的临床对比研究]. Modern Healthcare 2014;7:67.
Zhao 2003 {published data only}
    1. Zhao J, Liu R, Li H, Zhang Y. Different doses of mifepristone for emergency contraception [不同剂量米非司酮用于紧急避孕的临床观察]. Journal of Shandong University (Health Sciences) 2003;41:468.
Zheng 2005 {published data only}
    1. Zheng A. Low‐dose of mifepristone for emergency contraception [小剂量米非司酮用于紧急避孕的临床观察]. Youjiang Medical Journal 2005;4:375‐6.
Zuo 1999 {published data only}
    1. Zuo SH, Wu J, Liu L, Liu J, Gao Y. A clinical trial on two low doses of mifepristone for emergency contraception [两种低剂量米非司酮用于房事后紧急避孕的临床研究]. Reproduction & Contraception (China) 1999;6:352‐6.

References to studies excluded from this review

Ashok 2001 {published data only}
    1. Ashok PW, Wagaarachchi PT, Flett GM, Templeton A. Mifepristone as a late post‐coital contraceptive. Human Reproduction 2001;16:72‐5. - PubMed
Ashok 2004 {published data only}
    1. Ashok PW, Hamoda H, Flett GMM, Templeton A. Mifepristone versus the Yuzpe regimen (PC4) for emergency contraception. International Journal of Gynecology and Obstetrics 2004;87:188‐93. - PubMed
Ban 2001 {published data only}
    1. Ban X, Xiao Y, Fan H, Liu G, Liu Q, Yu L. A comparative clinical study on Tcu380A and Cu‐IUD for emergency contraception. Maternal & Child Health Care of China 2001;16:498‐501.
Benagiano G 2010 {published data only}
    1. Benagiano G, Hertzen H. Towards more effective emergency contraception?. Lancet 2010;375(9714):527‐28. - PubMed
Brache 2013 {published data only}
    1. Brache V, Cochon L, Deniaud M, Croxatto HB. Ulipristal acetate prevents ovulation more effectively than levonorgestral: analysis of pooled data from three randomized trials of emergency contraception regimens. Contraception 2013;88(5):611‐8. - PubMed
Byamugisha 2010 {published data only}
    1. Byamugisha JK, Mirembe FM, Faxelid E, Tumwesigye NM, Gemzell‐Danielsson K. A randomized clinical trial of two emergency contraceptive pill regimens in a Ugandan population. Acta Obstetricia et Gynecologica 2010;89:670‐6. - PubMed
Chen 2011 {published data only}
    1. Chen QJ, Xiang WP, Zhang DK, et al. Efficacy and safety of a levonorgestrel enteric‐coated tablet as an over‐the‐counter drug for emergency contraception: a Phase IV clinical trial. Human Reproduction (Oxford, England) 2011;26(9):2316‐21. - PMC - PubMed
Chen 2012 {published data only}
    1. Chen DY, Wang JL. A clinical observation on mifepristone and Yuzpe for emergency contraception. Chinese and Foreign Medical Research 2012;10(24):116‐7.
Creinin 1997 {published data only}
    1. Creinin MD. A reassessment of efficacy of the Yuzpe regimen of emergency contraception. Human Reproduction 1997;12:496‐8. - PubMed
D'Souza 2003 {published data only}
    1. D'Souza RE, Masters T, Bounds W, Guillebaud J. Randomised controlled trial assessing the acceptability of GyneFix versus Gyne‐T389S for emergency contraception. Journal of Family Planning and Reproductive Health Care 2003;29:23‐9. - PubMed
Dixon 1980 {published data only}
    1. Dixon GW. Ethinylestradiol and conjugated estrogens as postcoital contraceptives. JAMA 1980;244:1336‐9. - PubMed
Dong 2007 {published data only}
    1. Dong SZ, Wu SH. Comparing mifepristone, levonorgestrel and the copper IUD for emergency contraception: a report of 268 cases. Journal of Chinese Modern Gynecology and Obstetrics 4;2:127‐9.
Ellertson 2003b {published data only}
    1. Ellertson C, Evans M, Ferden S, Leadbetter C, Spears A, Johnestone K, et al. Extending the time limit for starting the Yuzpe regimen of emergency contraception to 120 hours. Obstetrics & Gynecology 2003;101:1168‐71. - PubMed
Espinos 1999 {published data only}
    1. Espinos JJ, Senosiain R, Vanrell C, Armengol J, Cuberas N, Calaf J. Safety and effectiveness of hormonal postcoital contraception: a prospective study. European Journal of Contraception and Reproductive Health Care 1999;4:27‐33. - PubMed
Fan 1998 {published data only}
    1. Fan Ai, Wang Y, Wang Z. Clinical study on 518 cases of emergency contraception. Chinese Journal of Family Planning 1998;6:408‐9.
Fan 2001b {published data only}
    1. Fan H, Zhou L. Emergency contraception with Multiload Cu 375 SL IUD: a multicentre clinical trial. Journal of Reproductive Medicine (China) 2001;10:70‐7. - PubMed
Fasoli 1989 {published data only}
    1. Fasoli M, Parazzini F, Cecchetti G, Vecchia CL. Post‐coital contraception: an overview of published studies. Contraception 1989;39:459‐69. - PubMed
Fine 2010b {published data only}
    1. Fine P, Mathe H, Ginde S, Cullins V, Morfesis J, Gainer E. Ulipristal acetate taken 48‐120 hours after intercourse for emergency contraception. Obstetrics and Gynecology 2010;115(2):247‐63. - PubMed
Gan 1999 {published data only}
    1. Gan SH, Chang M, Hu S, Zhang P, Chang M, Xu X. A clinical study on mifepristone 10mg for emergency contraception. Reproduction and Contraception (China) 1999;19:311‐3.
Gan SX 2001 {published data only}
    1. Gan SX, Li SS, Lu Y. Comparative study of the efficacy of mifepristone and levonorgestrel on the emergency contraception. Chinese Journal of Family Planning 2001;9:178‐81.
Gao 2001 {published data only}
    1. Gao ER, Zhao Sh, Lou CH. Study on the acceptability of emergency contraception among those who underwent induced abortion. Reproduction & Contraception (China) 2001;21:104‐9.
Glasier 2013 {published data only}
    1. Glasier A. Can we identify women at risk of pregnancy despite using emergency contraception? Data from randomized trials of ulipristal acetate and levonorgestrel. Obstetrical and Gynecological Survey 2013;68(3):208‐10. - PubMed
Gottardi 1979 {published data only}
    1. Gottardi G, Marzi MM, Pozzi S. Postcoital estrogen or IUD? [Oestrogène postcoital ou DIU?]. IPPF Europe Bulletin d'Information Régional 1979;8:7‐8. - PubMed
Gottardi 1986 {published data only}
    1. Gottardi G, Spreafico A, Orchi L. The postcoital IUD as an effective continuing contraceptive method. Contraception 1986;34:549‐58. - PubMed
Gu 2002 {published data only}
    1. Gu XY, Yie TF. Clinical study of the effect of Multiload 375 SL and levo‐norgestrel on emergency contraception. Chinese Journal of Family Planning 2002;10:740‐2.
Guillebaud 1983 {published data only}
    1. Guillebaud J, Kubba A, Rowlands S, White J, Elder EG. Postcoital contraception with danazol, compared with an ethinyloestradiol‐norgestrel combination or insertion of a intrauterine device. Journal of Obstetrics and Gynaecology 1983;suppl 1:s64‐8.
Halpern 2010 {published data only}
    1. Halpern V, Raymond EG, Lopez LM. Repeated use of pre‐ and postcoital hormonal contraception for prevention of pregnancy. Cochrane Database of Systematic Reviews 2010, Issue 1. [DOI: 10.1002/14651858.CD007595.pub2] - DOI - PubMed
Han 1999b {published data only}
    1. Han X, Wong L, Sun J. A clinical study on mifepristone alone and in combination with anordrin for emergency contraception. Chinese Journal of Family Planning 1999;7:411‐4.
Han 2001b {published data only}
    1. Han Y. The clinical observation of GyneFix IUD for emergency contraception. Journal of Practical Obstetrics and Gynecology 2001;17:171‐2.
Haspels 1976 {published data only}
    1. Haspels AA. Interception: post‐coital estrogens in 3016 women. Contraception 1976;14:375‐81. - PubMed
He 1991 {published data only}
    1. He C, Shi Y, Xu J, Look PFA. A multicenter clinical study on two types of levonorgestrel tablets administered for postcoital contraception. International Journal of Gynecology and Obstetrics 1991;36:43‐8. - PubMed
Ho 2013 {published data only}
    1. Ho PC. Levonorgestrel (LNG)‐development of hormonal methods of emergency contraception. European Journal of Contraception and Reproductive Health Care 2013;18:S44‐45.
Hoffman 1983 {published data only}
    1. Hoffman KOK. Postcoital contraception: experiences with ethinyl oestradiol/norgestrel and levonorgestrel only. In: Harrison RF, Bonnar J, Thompson W editor(s). Fertility and Sterility. Dublin: IFFS Fertility and Sterility, 1983:311‐6.
Jiang 2000 {published data only}
    1. Jiang L, Duan Y, Sun Y. A comparative study of mifepristone with levonorgestrel for emergency contraception. Chinese Journal of Family Planning 2000;8:463‐4.
Jiang 2002 {published data only}
    1. Jiang DX, Wu ER. Effects of gestrinone (R2323) on emergency contraception: a clinical observation of 120 cases. Journal of Reproductive Medicine 2002;11:326‐30.
Jin 2005 {published data only}
    1. Jin J, Weisberg E, Fraser IS. Comparison of three single doses of mifepristone as mifepristone as emergency contraception: a randomised controlled trial. Australian and New Zealand Journal of Obstetrics and Gynaecology 2005;45:489‐94. - PubMed
Kesserü 1973 {published data only}
    1. Kesserü E, Larranaga A, Parada J. Postcoital contraception with d‐norgestrel. Contraception 1973;7:367‐79.
Li 2001 {published data only}
    1. Li XY, Hu LY. A study of low‐dose mifepristone for emergency contraception. Chinese Journal of Practical Gynaecology and Obstetrics 2001;17:619‐20.
Li 2002b {published data only}
    1. Li F, Chen YX, Tang JH. Emergency contraception by low‐dose mifepristone: observation of 150 cases. Journal of First Military Medical University 2002;22:466. - PubMed
Li 2005a {published data only}
    1. Li F, Qian X, Wu W. A comparative study of mifepristone with Cu‐IUD for emergency contraception. Journal of Practice Medicine 2005;21:2313‐4.
Lippes 1976 {published data only}
    1. Lippes J, Malik T, Tatum HJ, Zielezny M. The postcoital copper‐T. Advances in Planned Parenthood 1976;11:24‐9. - PubMed
Lippes 1979 {published data only}
    1. Lippes J, Tatum HJ, Maulid D, Zielezny M. Postcoital copper IUD found to be effective in preventing pregnancy. Family Planning Perspectives 1979;11:195. - PubMed
Liu 2002a {published data only}
    1. Liu Y, Chen X. A comparative study of mifepristone with Cu‐IUD for emergency contraception. Journal of Qiqihar Medical College 2002;23:890‐1.
Luerti 1986 {published data only}
    1. Luerti M, Tonta A, Feria P, Molla R, Santini F. Post‐coital contraception by estrogen‐progestagen combination or IUD insertion. Contraception 1986;33:61‐8. - PubMed
Ma 2001 {published data only}
    1. Ma J. A study on 110 cases of emergency contraception. Chinese Journal of Practical Gynaecology and Obstetrics 2001;17:189.
Mo 2004 {published data only}
    1. Mo Y. A clinical observation on different dose of mifepristone for emergency contraception. Hainan Yi Xue 2004;15:42‐3.
Mor 2005 {published data only}
    1. Mor E, Saadat P, Kives S, White E, Reid RL, Paulson RJ, et al. Comparison of vaginal and oral administration of emergency contraception. Fertility and Sterility 2005;84:40‐5. - PubMed
Moreau 2012 {published data only}
    1. Moreau C, Trussell J. Results from pooled phase III studies of ulipristal scetate for emergency contraception. Contraception 2012;86:673‐80. - PMC - PubMed
Piaggio 2003a {published data only}
    1. Piaggio G, Heng Z, Hertzen H, Bilian X, Linan C. Combined estimates of effectiveness of mifepristone 10mg in emergency contraception. Contraception 2003;68:439‐46. - PubMed
Piaggio 2003b {published data only}
    1. Piaggio G, Hertzen H, Zhao H, Xiao BL, Cheng L. Meta‐analyses of randomized trials comparing different doses of mifepristone in emergency contraception. Contraception 2003;68:447‐52. - PubMed
Polakow 2013 {published data only}
    1. Polakow FS. Levonorgestrel used for emergency contraception during lactation‐A prospective observational cohort study on maternal and infant safety. Journal of Maternal‐Fetal and Neonatal Medicine 2013;26(3):219‐21. - PubMed
Qi 2000b {published data only}
    1. Qi Y, Zhang J, Cao Y, Yan W, Zhang Z. A clinical study on mifepristone at low dose for emergency contraception. Chinese Journal of Family Planning 2000;8:305‐7.
Qiao 2002 {published data only}
    1. Qiao Y. A clinical trial of mifepristone in combination with MTX for emergency contraception. Journal of Jining Medical College 2002;25:44.
Qin 2000 {published data only}
    1. Qin C. A clinical study on 137 cases of emergency contraception with mifepristone. Zhejiang Journal of Clinical Medicine 2000;2:302‐3.
Raymond 2000 {published data only}
    1. Raymond EG, Creinin MD, Barnhart KT, Lovvorn AE, Rountree RE, Trussell J. Meclizine for prevention of nausea associated with use of emergency contraceptive pills: a randomized trial. Obstetrics and Gynecology 2000;95:271‐7. - PubMed
Raymond 2006 {published data only}
    1. Raymond EG, Stewart F, Weaver M, Monteith C, Pol B. Impact of increased access to emergency contraceptive pills. Obstetrics and Gynecology 2006;108(5):1098‐106. - PubMed
Roye 2001 {published data only}
    1. Roye CF. Routine provision of emergency contraception to teens and subsequent condom use: a preliminary study. Journal of Adolescent Health 2001;28:165‐6. - PubMed
Ruan 2012 {published data only}
    1. Ruan JH. A clinical observation on LNG for emergency contraception [复方左炔诺孕酮用于紧急避孕的临床观察]. China Medicine and Pharmacy 2012;2(18):80‐1.
Scarduelli 1998 {published data only}
    1. Scarduelli C, Anselmino M, Caccamo A, Sezzi E, Lombroso Finzi GC. Emergency contraception: a new evaluation of effectiveness. P‐159. Abstracts of the 14th Annual Meeting of the ESHRF, Göteborg. 1998:208‐9.
Schilling 1979 {published data only}
    1. Schilling LH. An alternative to the use of high dose estrogen for postcoital contraception. Journal of American College of Health Association 1979;27:247‐9. - PubMed
Schreiber 2010 {published data only}
    1. Schreiber CA, Ratcliffe SJ, Barnhart KT. A randomized controlled trial of the effect of advanced supply of emergency contraception in postpartum teens: a feasibility study. Contraception 2010;81:435‐40. - PubMed
Scott 2012 {published data only}
    1. Scott LJ. Ulipristal acetate: a guide to its use in emergency contraception. Drugs and Therapy Perspectives 2012;28(2):6‐9.
Shaaban 2013 {published data only}
    1. Shaaban OM, Hassen SG, Nour SA, et al. Emergency contraceptive pills as a backup for lactational amenorrhea method (LAM) of contraception: a randomized controlled trial. Contraception 2013;87:363‐369. - PubMed
Shen 2010 {published data only}
    1. Shen HX. A observational study of mifepristone for emergency contraception. Journal of China Traditional Chinese Medicine Information 2010;2(28):163.
Shochet 2004 {published data only}
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Song 2007 {published data only}
    1. Song ZH, Wang Y, Chen P, Wang D, Lu WH. A clinical study of mifepristone and the copper IUD for emergency contraception. Chinese Medicine of Factory and Mine 2007;20(6):630‐1.
Sun 2005 {published data only}
    1. Sun Y, Che Y, Ding Y, Zhou W, Han Y, Fang K, et al. Systematic review of emergency contraception. Chinese Journal of Family Planning 2005;4:217‐22.
Tian 2000 {published data only}
    1. Tian Q. A comparative study of mifepristone with Cu‐IUD for emergency contraception. Journal of Henan Medical College for Staff and Workers 2000;12:51.
Turok 2010 {published data only}
    1. Turok DK, Gurtcheff SE, Handley E, Simonsen SE, Sok C, Murphy P. A pilot study of the copper T380A IUD and oral levonorgestrel for emergency contraception. Contraception 2010;82:520‐5. - PubMed
Turok 2014 {published data only}
    1. Turok DK, Jacobson JC, Dermish AI, Simonsen SE, Gurtcheff S, McFadden M, et al. Emergency contraception with a copper ICD or oral levonorgestrel: an observational study of 1‐year pregnancy rates. Contraception 2014;89(2014):222‐8. - PMC - PubMed
Turok 2016 {published data only}
    1. Turok DK, Sanders JN, Thompson IS. Preference for and efficacy of oral levonorgestrel for emergency contraception with concomitant placement of a levonorgestrel IUD: a prospective cohort study. Contraception 2016;93(6):526‐32. - PMC - PubMed
Van Santen 1983 {published data only}
    1. Santen MR, Haspels AA. Postcoital contraception with an IUD [Contraccezione con D.I.U. post‐coitale]. Contraccezione, Fertilita, Sessualita 1983;10:549‐57.
Van Santen 1985b {published data only}
    1. Santen MR, Haspels AA. Interception II: postcoital low‐dose estrogens and norgestrel combination in 633 women. Contraception 1985;31:275‐93. - PubMed
Virjo 1999 {published data only}
    1. Virjo I, Kirkkola AL, Isokoski M, Mattila K. Use and knowledge of hormonal emergency contraception. Advances in Contraception 1999;15:85‐94. - PubMed
Wang 2006b {published data only}
    1. Wang CP, Liu Y, Chang YF, Shao WQ. A comparing study of the copper intrauterine device and low dose of mifepristone for emergency contraception. Journal of Reproductive Medicine 2006;15(4):271‐3.
Wei 2002b {published data only}
    1. Wei R. Low‐dose of mifepristone for emergency contraception: observation of 309 cases. Jiangxi Medical Journal 2002;37:102‐4.
Wu 1999b {published data only}
    1. Wu C, Zhang Y. An extend study on using single dose of mifepriston 25mg for emergency contraception. Chinese Journal of Family Planning 1999;7:358‐60.
Wu 2005 {published data only}
    1. Wu S, Zhou Y. Clinical use of emergency contraception pill. Chinese Journal of Practical Gynaecology and Obstetrics 2005;21:15‐7.
Xiao 2004 {published data only}
    1. Xiao BL. Clinical study of emergency contraception with low‐dose mifepristone. Chinese Journal of Obstetrics and Gynecology 2004;39:35‐8. - PubMed
Yang 2002 {published data only}
    1. Yang Y, Liang X, Liu X. Low‐dose of mifepristone for emergency contraception: observation of 106 cases. Heilongjiang Medical Journal 2002;26:283.
Ye 2014 {published data only}
    1. Ye JM. A clinical observation on LNG for emergency contraception. Chinese journal of ethnomedicine and ethnopharmacy 2014;9:75.
Yu 2001 {published data only}
    1. Yu MD. A primary discussion of the drugs for emergency contraception. Anhui Medical and Pharmaceutical Journal 2001;5:95‐6.
Yuzpe 1974 {published data only}
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Yuzpe 1977 {published data only}
    1. Yuzpe AA, Lancee WJ. Ethinylestradiol and dl‐norgestrel as a postcoital contraceptive. Fertility and Sterility 1977;28:932‐6. - PubMed
Yuzpe 1982 {published data only}
    1. Yuzpe AA, Percival Smith R, Rademaker AW. A multicentre clinical investigation employing ethinylestradiol combined with dl‐norgestrel as a postcoital contraceptive agent. Fertility and Sterility 1982;37:508‐13. - PubMed
Zhang 1999a {published data only}
    1. Zhang J, Jing X, Wong L. Cu‐IUD versus mifepristone for emergency contraception. Chinese Journal of Obstetrics and Gynecology 1999;34:569‐70.
Zhang 1999c {published data only}
    1. Zhang M, Yang H, Wang Z, Liang X, Wang Y. A study on mifepristone alone and in combination with anordrin for emergency contraception. Zhejiang Journal of Practical Medicine 1999;4:1‐2.
Zhang 1999d {published data only}
    1. Zhang X, Du M, Ying Y. A study on mifepristone alone and in combination with anordrin for emergency contraception. Reproduction and Contraception (China) 1999;19:163‐8.
Zhang 1999e {published data only}
    1. Zhang X, Leng Y, Shi J, Gao G, Xu Y, Sun H. A study on LNG for emergency contraception. Chinese Journal of Family Planning 1999;7:375‐6.
Zhao 2006 {published data only}
    1. Zho H, Han L. Analysis of the reason for failure of emergency contraception. Journal of China‐Japan Friendship Hospital 2006;20:207‐10.
Zhao H 2001 {published data only}
    1. Zhao H, Tang JR, Wu MH, Cheng H. A comparative study of mifepristone with IUCD for emergency contraception. Journal of Capital University of Medical Sciences 2001;22:273‐4.
Zhu 1999 {published data only}
    1. Zhu P, Chai J, Wang N, Li G. An initial observation of mifepristone combined with MTX for the use of emergency contraception. Guangdong Journal of Medicine 1999;20:11‐2.
Zhu 2007 {published data only}
    1. Zhu YH, Ou YL. Clinical observational study of three methods for emergency contraception. Journal of Medical Theory and Practice 2007;20(2):200‐2.
Zuliani 1990 {published data only}
    1. Colombo UF, Zuliani G, Benzi G, Bregozzo T, Viezzoli T. [Contraccezione post coitale ormonale con danazolo: ristati di due differenti schemi posologici]. Pediatric and Adolescent Gynaecology. Paper presented at the III European Symposium on Pediatric and Adolescent Gynaecology; 1987 Oct 7‐10; Florence. Florence, Italy: CIC Edizioni Internazionali, 1987:206‐11.
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    1. Zuliani G, Colombo UF, Molla R. Hormonal postcoital contraception with an ethinylestradiol‐norgestrel combination and two danazol regimens. European Journal of Obstetrics Gynecology and Reproductive Biology 1990;37:253‐60. - PubMed
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References to ongoing studies

NCT01539720 {unpublished data only}
    1. NCT01539720. Levonorgestrel intrauterine system for emergency contraception (LIFE). clinicaltrials.gov/show/NCT01539720 first received: 21 February, 2012.
NCT02175030 {unpublished data only}
    1. NCT02175030. RAPID EC ‐ RCT assessing pregnancy with intrauterine devices for EC. clinicaltrials.gov/show/NCT02175030 first received: 23 June , 2014.
NCT02577601 {unpublished data only}
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References to other published versions of this review

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