***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: A levonorgestrel-releasing IUD and the Copper T 380Ag IUD were in r and omized comparison for seven years in five clinics . In two other clinics the r and omized study was truncated at five years , but use of the Copper T continued . No pregnancies occurred to users of either device in years 6 and 7 . Cumulative pregnancy rates were 1.1 per 100 at seven years for the steroid-releasing and 1.4 per 100 for the copper-releasing IUDs .  Cumulative rates of PID did not differ between devices . Infection rates appeared to be lowest during the sixth and seventh years of the study . Termination attributable to amenorrhea was the principal contributor to differences in cumulative continuation rates between devices . At the five clinics that carried the comparative study to seven years , cumulative continuation rates were 24.9 per 100 for LNg20 IUD users and 29.4 per 100 for TCu 380Ag users . Women who used either method for periods of five to seven years experienced , on average , marked to mild increases in hemoglobin as compared with levels at admission . The Copper T380 family and the LNg20 IUDs represent the most effective reversible contraceptive methods yet studied in long-term r and omized trials IUDs releasing 20 mcg/day of levonorgestrel ( LNg20 ) were in r and omized trial together with the Copper T , model TCu 380Ag , in seven centers involving 2244 women . Two-year ( 25 months ) gross cumulative pregnancy rates were 0.2 + /- 0.2 and 0.9 + /- 0.3 for the levonorgestrel and copper releasing devices , respectively ( P greater than 0.05 ) . There were no ectopic pregnancies in more than 1600 woman-years of use of each device . Removal rates for bleeding and /or pain or for medical reasons other than menstrual problems did not differ significantly between devices . Oligomenorrhea or amenorrhea prompted 10.7 per hundred ( gross rate , 8.4 net rate ) women using the LNg 20 IUD to request removal in the two-year period , significantly above the 0.2 per hundred rate among women with the Copper IUD ( P less than 0.001 ) . At the end of two years an estimated 59.4 per 100 women were continuing use of the LNg 20 IUD , and 67.5 per 100 ( P less than 0.001 ) with the TCu 380Ag . This difference is almost wholly ascribable to a marked reduction in bleeding episodes and days among women using the LNg 20 device with concomitant removal of device . Hemoglobin rose an average of 0.5 g/dl ( P less than 0.001 ) for this group whereas women using the TCu 380Ag experienced a decline of 0.2 g/dl compared with baseline values ( P less than 0.001 ) In 90 women with a norgestrel‐releasing IUCD inserted and 50 women having a copper releasing IUCD  , cul‐turing of cervical and vaginal secretion was performed prior to , and 3 and 12 months after insertion of the IUCD . There were no significant changes in the cervical or vaginal microflora , and no significant differences between the groups . According to these findings , locally released progestogens from an IUCD do not affect the microflora of the vagina or of the cervix The clinical performance of a levonorgestrel IUD , releasing 20 mcg/day , used by 293 women at the Family Planning Clinic of the State University of Campinas , was evaluated up to the end of the seventh year of use .  No pregnancies  occurred in 899 women-years of observation . The cumulative removal rate for amenorrhea or severe hypomenorrhea was 15.7 per 100 women at seven years . The expulsion rate was within ranges observed with copper IUDs in the same clinic . The continuation rate was 49.5 % at three years and 23.7 at seven years . The cumulative loss to follow-up rate was 13.7 % at seven years . The effectiveness , good continuation rate , and reduction of the amount of blood loss make this device appropriate to be offered to Brazilian women , as an additional contraceptive option An improved long-acting Norgestrel-T contraceptive device has been developed . The effects of different release levels of levonorgestrel on the endometrium were studied in a selected group of 42 subjects . A r and omized comparative study of the clinical performance of Cu-T 200 and Ng-T devices was undertaken in 200 fertile women for 15 months . Quantitation of the menstrual blood loss was performed on a selected group of 20 users . This new Ng-T device proved highly effective in fertility control . It was associated with a significant reduction in the amount of menstrual blood loss and incidence of termination probabilities due to bleeding and pain A r and omized comparative performance study of two  levonorgestrel intrauterine devices ( IUDs )  and a copper ( Nova-T ) IUD  ( Leiras , Turku , Finl and ) was performed at two clinics in Finl and and one in Brazil . The 24-month cumulative event rates per 100 women are reported . Six thous and woman-months of use were recorded with the levonorgestrel IUD and 3000 with the Nova-T device .  Pregnancy rates at 2 years of use were 0.6 and 0 with the two levonorgestrel IUDs and 3.3 with the Nova-T IUD .  Removal rates because of bleeding and /or pain were low with all three IUDs : 7.5 , 7.6 , and 7.1 , respectively , at 24 months . Recordings of the number of days of bleeding showed significantly fewer days of bleeding during use of the levonorgestrel IUDs than the Nova-T IUD from the second month of use onward , until the end of the second year . No infections were recorded in association with use of the levonorgestrel IUDs , and only one termination because of infection was recorded for the Nova-T IUD . The continuation rates of use at 24 months were 66.6 , 60.7 , and 71.9 for the two levonorgestrel IUDs and the Nova-T IUD , respectively ; the differences were not statistically significant Data obtained from question naires on the occurrence of  dysmenorrhoea in women using IUDs inserted r and omly ( 146 of them Progestasert and 149 Copper 7 ) are analyzed . In both groups a reduction in the intensity of menstrual cramps was observed over 12 months of use . Although these reductions are significant in each group , they are slightly higher in Progestasert users . However , on comparing the reduction tendencies of both groups , the difference between them is not significant . No significant differences become apparent either when comparing premenstrual and intermenstrual camps . The usefulness of simple question naires directed at detecting the nature of pain in currently used family planning forms for IUD users is discussed A r and omized study was performed in two clinics in order to compare the efficacy , safety and acceptability of a new model of a levonorgestrel-releasing intracervical device situated either in the cervical canal ( group I ) or in the uterine cavity ( group II ) . Group I included 151 women ( age 18 - 43 ) and group II , 147 women ( age 19 - 43 ) . The number of nulliparous women was 145 . The total expulsion rate was 9.1 % . The expulsion rate was lower among nulliparous women ( 4.8 % ) than among parous women ( 13.1 % ) . There was also a significant difference in the expulsion rates between the two clinics . Two pregnancies occurred in both groups and two of these were ectopic , one in each group . The other two occurred after unnoticed expulsion . These figures give 12-month cumulative pregnancy rates of 1.3 % and 1.4 % in groups I and II , respectively . Total infection rate was 0.3 % . The continuation rates were 82.1 % in group I and 85.0 % in group II after the first year . At three-month follow-up there were significantly fewer menstrual problems in group I than in group II ( p = 0.0266 ) . It is concluded that expulsion is still a problem with a small device but it may be diminished by intrauterine insertion and by selecting the users carefully Increased menstrual blood loss ( MBL ) associated with intrauterine device  (  IUD )  use may precipitate or aggravate iron deficiency anaemia , adversely affecting the health of women particularly those from developing countries . Studies were conducted to define the association of MBL and iron status in South American women ; to determine the level of MBL induced by IUD use which would result in iron depletion , the length of time for this depletion to occur and , comparing various IUDS , to determine if any currently tested IUDs are suited to long-term use in South American women . A total of 395 women received one of 5 types of IUDs in Santiago , Chile , and Juiz de Fora , Brazil :  Lippes Loop , Multiload-250 and Multiload-375 were used in both centres ; in Santiago some subjects received the Copper-7 or ProgestasertR devices and in Juiz de Fora , the TCu 200 and the T-Chloroquin IUDs were also tested . MBL and haemoglobin ( HGB ) were measured for 3 menstrual cycles before insertion , and following insertion , at one , two , four , six , nine , twelve , eighteen and twenty-four months in the majority of cases . Serum ferritin was measured before insertion and at intervals of six months . Mean values of MBL prior to IUD insertion in both centres varied from 21 - 30 ml . As with previous publications , the use of the Lippes Loop was associated with the greatest increase in MBL which was sustained throughout the 24 months of observation . Women who had one of the two types of Multiload devices inserted also had increased MBL and reduced ferritin for at least 12 months of use . TCu 200 and Copper-7 IUD users had an initial increase in MBL of 1 to 17 ml in the first six months of observation returning to normal levels beyond six months . Serum ferritin levels were lower for one year and then returned to admission values . ProgestasertR users confirmed previous reports of a reduction of 40 - 50 % in MBL and an increase in serum ferritin . Few significant changes in haemoglobin ( HGB ) concentrations were found . Serum ferritin levels on admission ranged from 7.1 to 16.4 ng/ml in Santiago and from 15.8 to 23.2 ng/ml in Juiz de Fora . Many women were in a marginal state of iron balance as evidence d by lower serum ferritin values . Changes in serum ferritin were very closely related to those in MBL . ( ABSTRACT TRUNCATED AT 400 WORDS In a prospect i ve , r and omized clinical trial of 2 IUDs , the Progestasert  ( 1963 women ) and the Cu T200  ( 186 women ) , there were no significant differences observed after a period of 12 months of observation , particularly with regard to efficacy . The Progestasert , however , must be changed at most 18 months after insertion ; thus , this IUD is less practical than the Cu T200 . ( author 's The clinical performance of two levonorgestrel-releasing intrauterine devices ( IUDs )  with different release rates was studied and compared with a copper-releasing Nova-T device in a r and omized partly double-blind multi clinical trial . Special attention was given to patterns of bleeding , hormonal side-effects , blood pressure and body weight . The clinical acceptability of the levonorgestrel IUDs was as good as that of the copper-releasing IUD . A highly significant decrease in the amount of menstrual blood loss was seen with the levonorgestrel-IUDs , the users of which experienced fewer days of bleeding than prior to insertion . Patients suffering from dysmenorrhea experienced relief from this symptom after insertion of a levonorgestrel-IUD . Some side-effects , usually referred to as hormonal , increased during the levonorgestrel-IUD use , but did not result in higher termination rates than with the Nova-T device . No changes in body weight were recorded for the levonorgestrel-IUDs and a slight decrease in both systolic and diastolic blood pressure was found after one year of use . No infections were recorded An intrauterine device , releasing approximately 20 micrograms/day of levonorgestrel ( LNg 20 ) , used by 1124 women , was studied in a r and omized trial of five years duration in comparison with the Copper T , model TCu 380Agm  in 1121 women . At five years , the gross cumulative pregnancy rate of 1.1 + /- 0.5 per 100 among users of the LNg 20 devices was not significantly different from the rate of 1.4 + /- 0.4 per 100 experienced by users of the Copper T 380Ag . The steroid-releasing IUD had significantly higher termination rates for expulsion and amenorrhea , a significantly lower termination rate for other menstrual problems and pain , and a lower continuation rate . The five-year continuation rate among women using the TCu 380Ag was 40.6 per 100 as compared with that of 33.0 per 100 among women r and omized to the LNg 20 device ( P less than .001 ) . Terminations attributed to amenorrhea with the LNg device primarily account for differences in continuation . These 
    Output:
    
LNG-20 users were significantly more likely than all the IUD users to discontinue because of hormonal side effects and menstrual disturbance , which on further breakdown of the data was due to amenorrhoea .
When the LNG-20 IUS was compared to Norplant-2 , the LNG-20 users were significantly more likely to experience amenorrhoea and oligomenorrhoea , but significantly less likely to experience prolonged bleeding and spotting .
No other significant differences were observed .
Progestasert users were significantly less likely to become pregnant and less likely to continue on the method than non-medicated IUD users after one year , but no significant differences was noted for these two outcomes when Progestasert users were compared to IUD<=250mm2 users .
REVIEW ER 'S CONCLUSIONS Current evidence suggests LNG-20 IUS users are no more or less likely to have unwanted pregnancies than IUD > 250mm2 and Norplant-2 users .
The LNG-20 IUS was more effective in preventing either intrauterine or extrauterine pregnancies than IUDs < = 250mm2 .
The contraceptive effectiveness of Progestasert was significantly better than non-medicated IUDs , but no difference was observed when compared to IUDs<=250mm2 .
Continuation of LNG-20 IUS use was similar to continuation of the non-hormonal IUDs and Norplant-2 .