***TASK*** the task is to summarize an input biomedical literature in six sentences 
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    Input: Objective To compare 100 mg mifepristone with the st and ard Yuzpe regimen for emergency contraception BACKGROUND A single 10 mg dose of mifepristone , and two 0.75 mg doses of levonorgestrel 12 h apart , are effective for emergency contraception . Because no studies had compared the efficacies of both compounds , or investigated a single dose of 1.5 mg levonorgestrel , we undertook this three-arm trial . METHODS We did a r and omised , double-blind trial in 15 family-planning clinics in 10 countries . We r and omly assigned 4136 healthy women with regular menstrual cycles , who requested emergency contraception within 120 h of one unprotected coitus , to one of three regimens : 10 mg single-dose mifepristone ; 1.5 mg single-dose levonorgestrel ; or two doses of 0.75 mg levonorgestrel given 12 h apart . The primary outcome was unintended pregnancy ; other outcomes were side-effects and timing of next menstruation . Analysis was by intention to treat , but we did exclude some patients from the final analyses . FINDINGS Of 4071 women with known outcome , pregnancy rates were 1.5 % ( 21/1359 ) in those given mifepristone , 1.5 % ( 20/1356 ) in those assigned single-dose levonorgestrel , and 1.8 % ( 24/1356 ) in women assigned two-dose levonorgestrel . These proportions did not differ significantly ( p=0.83 ) . The relative risk of pregnancy for single-dose levonorgestrel compared with two-dose levonorgestrel was 0.83 ( 95 % CI 0.46 - 1.50 ) , and that for levonorgestrel ( the two regimens combined ) compared with mifepristone , 1.05 ( 0.63 - 1.76 ) . Side-effects were mild and did not differ greatly between groups , and most women menstruated within 2 days of the expected date . Women who took levonorgestrel had earlier menses than did those who took mifepristone . INTERPRETATION The three regimens studied are very efficacious for emergency contraception and prevent a high proportion of pregnancies if taken within 5 days of unprotected coitus . Mifepristone and levonorgestrel do not differ in efficacy . A 1.5 mg single levonorgestrel dose can substitute two 0.75 mg doses 12 h apart Twenty-seven women requesting postcoital contraception were r and omly allocated to take an ethinylestradiol/dl-norgestrel combination or danazol . Urine specimens were assayed for luteinising hormone ( LH ) and pregnanediol-3-glucuronide ( P3 G ) levels from the day of the postcoital treatment to the next period . In addition , the urine sample s of these recruits and 12 additional women were assayed for the Beta-subunit of human chorionic gonadotropin ( B-hCG ) . A consistent pattern of alteration in urinary steroids was lacking , indicating a heterogeneous effect on ovarian function . There was no evidence of early pregnancy in successfully treated cases . We suggest that the main mechanism of action of these drugs is at the endometrial level OBJECTIVE --To compare the effectiveness and acceptability of three regimens of postcoital contraception . DESIGN --R and omised group comparison of ethinyloestradiol 100 micrograms plus levonorgestrel 500 micrograms repeated after 12 hours ( Yuzpe method ) ; danazol 600 mg repeated after 12 hours ; and mifepristone 600 mg single dose . SETTING --Community family planning clinic . SUBJECTS--616 consecutive women with regular cycles aged 16 to 45 years . MAIN OUTCOME MEASURES --Number of pregnancies , incidence of side effects , and timing of next period . RESULTS --The raw pregnancy rates ( with 95 % confidence intervals ) for the Yuzpe , danazol , and mifepristone groups were 2.62 % ( 0.86 % to 6.00 % ) , 4.66 % ( 2.15 % to 8.67 % ) , and 0 % ( 0 % to 1.87 % ) respectively . Overall , these rates differed significantly ( chi 2 = 8.988 , df = 2 ; p = 0.011 ) . The differences between the mifepristone and Yuzpe groups and between the mifepristone and danazol groups were also significant . Side effects were more common and more severe in the Yuzpe group ( 133 women ( 70 % ) ) than in either the danazol group ( 58 ( 30 % ) ) or the mifepristone group ( 72 ( 37 % ) ) . The Yuzpe regimen tended to induce bleeding early but mifepristone prolonged the cycle . Three women bled more than seven days late in the Yuzpe group compared with 49 in the mifepristone group . CONCLUSIONS --Mifepristone was effective in reducing expected pregnancy rates and the Yuzpe method also had a clinical effect . Danazol had little or no effect . A further multicentre trial is needed Objective We conducted a r and omized trial to determine whether pretreatment with meclizine reduces the incidence of nausea and vomiting associated with the Yuzpe regimen of emergency contraception . Methods We r and omly assigned 343 women aged 18–45 years who were not at risk for pregnancy to pretreatment with 50 mg of meclizine , placebo , or no drug 1 hour before the first of two doses of emergency contraceptive pills . We asked participants to complete three question naires over the following 48 hours . Results The incidence of nausea was 47 % in the group pretreated with meclizine and 64 % in the other two groups ( relative risk adjusted for center 0.7 , 95 % confidence intervals 0.6 , 0.9 for comparisons of meclizine with both placebo and no drug ) . The severity of nausea and the incidence of vomiting were also significantly lower in the meclizine pretreatment group than in the other two groups . Drowsiness was reported by about twice as many women in the meclizine pretreatment group ( 31 % ) than in the other two groups ( 13 % in the placebo group , 16 % in the no-pretreatment group ; P < .01 for both comparisons ) . Conclusion Meclizine is effective for preventing nausea and vomiting associated with the Yuzpe regimen of emergency contraceptive pills . Women using this drug should be caution ed to anticipate drowsiness Ethinylestradiol ( EE ) , at a dosage of 5 mg/day for 5 consecutive days ( 5 mg EE ) , has generally been used for interception . A combination of 200 micrograms EE and 2 mg dl-norgestrel ( EE + NG ) was proposed as an effective alternative . Efficacy and tolerance of these methods were compared in a r and omized , double-blind study . A group of 465 women was studied with a follow-up rate of 94.3 % . In the 5 mg EE group a pregnancy rate of 0.9 % was observed , and in the EE + NG group a rate of 0.4 % was found . These rates differ significantly from the expected rates ( P less than 0.0005 , in both series ) . Nausea was noted in 59.1 % of the 5 mg EE group and in 54.0 % of the EE + NG series . Nausea and vomiting occurred in 20.8 % and 15.8 % , respectively . The efficacy of both methods as alternative morning-after medication was confirmed . The new method is preferable because treatment is limited to only 1 day Emergency contraception was introduced in Nigeria over two decades ago , but few women have used this method even in emergency situations because of the side effects . To find an acceptable levonorgestrel regimen for emergency contraception in our community , the two-dose regimen 0.75-mg levonorgestrel 12 h apart ( group A ) and the single dose 1.5-mg levonorgestrel ( group B ) were studied in 1118 volunteers .  Mild side effects such as nausea , vomiting , lower abdominal pains , menorrhagia , dizziness , headache , and breast tenderness were reported . Significantly more women in the high-dose group reported headache , breast tenderness , and heavy menstrual flow . Eleven pregnancies ( 1.0 % ) were reported ( 7 in group A and 4 in group B ) . The crude relative risk of pregnancies was similar in the two groups ( RR = 0.71 , 95 % CI = 0.32 - 1.55 ; p > 0.05 ) [ corrected ] . On the other h and , the estimated effectiveness rate of 86.80 % in group A was significantly lower than the 92.99 % for group B ( p < 0.05 ) . The pregnancy rates increased with delay in starting treatment and if further acts of unprotected sexual intercourse took place after treatment . It was concluded that both regimens were effective and safe A two-year controlled clinical study of the effectiveness of postcoital IUD as a continuing contraceptive method in 98 women requesting a postcoital contraception is presented . The control group was selected from women requesting an IUD as contraceptive choice . The rates of accidental pregnancy , expulsion and removal for medical reasons did not differ between the two groups . Removal for personal reasons was the only termination event that showed a significant difference at one year . Moreover , the removal for personal reasons of interceptive IUD users mainly occurred in the early months after insertion . Postcoital IUD has proved to be an effective continuing contraceptive method . Special attention and sympathetic counseling should be given to postcoital IUD users before insertion and during the three months following insertion The study compares the effectiveness and acceptability of three regimes of postcoital contraception : 1 ) ethinylestradiol 100 μg/levonorgestrel 500 μg repeated after 12 hours ( Yuzpe method ) ; 2 ) danazol 600 mg repeated after 12 hours ; and 3 ) RU486 600 mg single dose .  Between 1 April 1990 and 15 October 1990 , 215 women were selected and r and omly allocated to the three treatment groups . One hundred and sixty eoght were fully followed up , 35 ongoing and 8 lost to follow-up . All women had regular cycles and were aged 16–45 years . All treatments were given within 72 hours of unprotected intercourse and follow-up was until normal menstruation or diagnosis of pregnancy . β-HCG was measured quantitatively where there was a suspicion of pregnancy . The data obtained show similar failure rates  ( Yuzpe 1/57 , danazol 2/57 , RU486 1/54 ) but more side-effects in the Yuzpe group ( nausea 74.1 % , vomiting 22.4 % , breast tenderness 22.4 % ) than in the other two ( danazol : nausea 31.6 % , vomiting 3.5 % , breast tenderness 19.3 % ) and ( RU486 :  nausea 36.4 % , vomiting 3.6 % , breast tenderness 23.6 % ) . There was one apparent allergic reaction in the danazol group . RU486 caused greater cycle disturbance , prolonging the cycle considerably . Initial results suggest that danazol and RU486 may be much more acceptable methods of postcoital contraception due to reduced side-effects and , in the latter case , single dose . Although numbers are small at present , the effectiveness of the newer methods appear similar to Yuzpe . ResuméCette étude compare l'efficacité et l'acceptabilité de trois protocol es de contraception postcoïtale : 1-ethinylestradiol 100 μg/lévonorgestrel 500 μg , renouvelé douze heures après . 2-Danazol 600 mg , renouvelé après 12 heures . 3-RU 486 , 600 mg en dose unique . Entre le 1er avril 1990 et le 15 octobre 1990 , 215 femmes ont été choisies et réparties par r and omisation dans trois groupes de traitement . 168 ont été suivies du début à la fin , 35 sont en cours de suivi , et 8 ont ab and onné l'étude . Toutes les femmes avaient des cycles réguliers et étaient âgées de 16 à 45 ans . Tous les traitements ont été administrés dans les 72 heures après un rapport non protégé et le suivi a continué jusqu'à l'apparition d'une menstruation normale ou l'établissement d'un diagnostic de grossesse . Le résultat obtenu fait apparaître des taux d'échec identiques ( Yuzpe 1/57 , Danazol 2/57 , RU 486 1/54 ) , mais avec plus d'effets secondaires dans le groupe Yuzpe ( nausées 74.1 % , vomissements 22.4 % , tension mammaire 22.4 % ) que dans les deux autres groupes ( Danazol : nausées 31.6 % , vomissements 3.5 % , tension mammaire 19.3 % et RU 486 : 
    Output:
    
Delay in the onset of subsequent menses was the main unwanted effect of mifepristone and seemed to be dose-related .
Mifepristone middle dose ( 25 - 50 mg ) was superior to other hormonal regimens .
Mifepristone low dose ( < 25 mg ) could be more effective than levonorgestrel 0.75 mg ( two doses ) but this was not conclusive .
Levonorgestrel proved more effective than the Yuzpe regimen .
The copper IUD was another effective emergency contraceptive that can provide ongoing contraception