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A randomised comparative evaluation of the copper 7, multiload copper 250 and T Copper-220C IUDs
CONTRACEPTION
A RANDOMISED COMPARATIVE EVALUATION OF THE COPPER 7, MULTILOAD COPPER 250 AND T COPPER-220C IUDs
T.H. Goh, T.A. Sinnathuray, V. Sivanesaratnam, & D.K. Sen Department of Obstetrics & Gynaecology, University of Malaya, Kuala Lumpur, Malaysia
L.S. Lim, S.S. Ratnam, S.M.M. Karim & T. McCarthy Department of Obstetrics & Gynaecology, National University of Singapore, Singapore
H. Hutapea, M.J. Hanafiah & P. Simandjuntak Department of Obstetrics & Gynaecology, University of North Sumatra, Medan, Indonesia
ABSTRACT Two new Cu-IlJDs, the TCu-220C and Multiload Cu250, were evaluated against the Cu7 in 1,199 subjects in a randomised, multicentric trial using a common study protocol. During the 2 years following insertion, cumulative first-segment rates for total use-related terminations showed no significant differences between the 3 devices; however, the Cu7 had a significantly higher termination rate for accidental pregnancy compared to the TCu-220C and its expulsion rate was significantly higher than the ML Cu250. The rate of accidental pregnancy was higher and the expulsion rate lower with the ML Cu25O compared to the TCu-220C but these differences were not significant. The results are discussed in relation to IUD design and their application in family planning.
Submitted for publication September 18, 1981 Accepted for publication December 17, 1982
JANUARY
1983 VOL. 27 NO. 1
75
CONTRACEFTION INTXODUCTION
High use-effectiveness in both parous and nulliparous women have been reported with the TCu-220C (1,2,3) and Multiload 250 (ML Cu 250) IUDs (4,5,6). However, comparative studies with the Cu7 (7,8) have not hitherto allowed an objective evaluation of these newer IUDs because many factors that influence IUD performance were not controlled (9). Thus, whether these newer IUDs are better and whether the hypothetical basis for their design are valid have not been adequately tested. In this study the ML Cu 250 and TCu-220C were evaluated using the Cu7 as the standard. In order that a meaningful comparison could be made, the essential criteria as outlined by Mishell were observed (9). The study commenced on 1st April 1975 at three University centres in Kuala Lumpur (Malaysia), Singapore and in Medan (North Sumatra). The cut-off date was Jlst December 1980. The Cu-IUDs are small devices: eact:measures 36 nun in length and is provided with a monofilament tail for retrival. The rationale for the design of the ML Cu 250 (4,s) and the TCu-220C (10) have previously been reported. The Cu7 requires no further introduction, having been extensively tested before.
MATERIALS AND MSTHODS SubSects were only included for study if they satisfied the following criteria: (i) healthy, informed volunteers aged 19-35 years who would rely solely on the Cu-IUD for contraception, (ii) general and pelvic examination revealed no pathology including the Papanicolaou smear, (iii) no less than 4 weeks postabortal and 8 weeks postpartum, (iv) frequently exposed to the risk of pregnancy, i.e. currently cohabiting and had at least one previous pregnancy, and (v) ability to come for follow-up and to complete the menstrual diary card. The standard contraindications to Cu-IUD insertion were followed (LO). The Cu-IUDs were supplied in individual sterile packages. Insertion technique was as previously described for the Cu7 (11); the TCu220C and ML Cu 250 were inserted according to the manufacturers' instructions. The type of IUD inserted leas based on random allocation and only known just prior to insertion. The follow-up examinations
76
JANUARY
1983 VOL. 27 NO. 1
CONTRACEPTION
were scheduled at 6 weeks, 3 months, 6 months, one year and finally at 2 years. Defaulters were traced by means of telephone or mail and home visits carried out if there was no response. Data on the first-segment of IUD use were analysed using the life-table method with definitions as set out by Tietze and Lewit (12). A computer program was used for analysis and differences in gross rates were compared using chi square (12,13,14).A value of p>O.Os is considered not statisticallysignificant. RESULTS There were 1,199 insertions: Singapore 452, Kuala Lumpur 344 and Medan 403. At the cut-off date, 825 (69%) had completed 2 years: 261 with the Cu7, 286 with the TCu-220C and 278 with the ML Cu250. Failure of insertion was encountered in 4 cases: one each with Cu7 and TCu-220C, and two with ML Cu250. The distributionof age, parity and previous contraceptive history in the three Cu-IUD populations are shown in Tables I-III; as expected, no significant differences were observedbetween them. The study population was generally young and of low parity: 840 or 70% were under 30 years old while 58% were of parity O-2. The net and gross cumulative first segment termination rates are presented in Tables IV and V. Significantdifferencesbetween the 3 devices were found only in their rates of expulsionand accidental pregnancy. Exoulsion The Cu7 had the highest expulsion rate and this was significantly higher compared to the ML Cu250 (p < 0.05). The difference between the ML Cu250 and TCu-220C and between the Cu7 and TCu-220C were not significant. AccidentalPregnancy There were 35 accidental pregnancies,all of which were intrauterine; none had a completely expelled IUD while partial expulsion was only found with the Cu7; in most cases, this had not been noticed by the patient. The rate was higher in the Cu7 compared to the TCu-220C (p < 0.05) but the difference between the Cu7 and ML Cu250 did not reach significantlevels.
JANUARY
1983 VOL. 27 NO. 1
CONTRACEPTION
TABLE I
Method
CONTRACEPTIVE HISTORYOF IUD USERS (%)
cu7 N = 398
TCu-220C N = 401
ML cu250 N = 400
None
36.9
32.1
32.0
Pill
21.8
21.1
25.7
Injectables
1.2
0.7
1.0
IUD
9.0
10.2
7.0
21.3
Other More than one
TABLE II
Age Group (years)
9.5
20.9
22.0
14.7
12.2
AGE DISTRIBUTIONOF IUD USERS ($1
cu7
TCu-220C
2.0
2.7
3.3
20 -
27.9
28.2
24.5
25 -
42.0
38.2
41.5
30 -
23.1
24.9
24.8
Under 20
35 -
5.0
5.2
6.0
Unknown
0.0
0.7
0.0
Mean (SE)
78
27.1 (0.2)
27.1 (0.22)
27.4 (0.22)
JANLJARY 1983 VOL. 27 NO. 1
CONTRACEPTION
Other Terminations There were no significant differences between the 3 IUDs in non-userelated terminations and in use-related IUD removals. There were no uterine or cervical perforations and clinically diagnosed pelvic infection was recorded once with each device. Comparison between 3 Centres For the Cu7, TCu-220C and ML Cu250,respectively, no significant differences were found in each category of use-related terminations when the three study centres were compared.
TABLE III
PARITY DISTRIBUTION OF IUD USERS (%I
cu7
TCu-220C
ML cu250
0
6.5
7.4
7.7
1
14.5
15.7
16.2
2
33.4
35.1
35.5
3
23.1
20.1
22.0
Over 3
22.3
21.4
18.5
Parity
Mean (SE)
2.64
(0.08)
2.50
(0.08)
2.44 (0.08)
DISCUSSION In this investigation, the 3 IUDs were tested under identical conditions so that the IUD was the only important variable studied; the success of this approach is reflected in the relative uniformity achieved in the results from the 3 centres and in the distribution of age, parity and contraceptive history among the respective Cu-IUD groups.
JANUARY
1983 VOL. 27 NO. 1
79
CONTRACEPTION
00.
. .
r?o Y
0;;: &d v
hi f 0
80
JANUARY 1983 VOL. 27 NO. 1
1.6
other personal reasons
2243
91.2
2095
86.1
Continuation rate
91.6
2233
78.6
3942
(2.1)
Woman-months
21.4
2.4
3.2
(1.8)
(%
0.8
O-5
2.1
4.2
5.7
3.9
cu7
13.9
(::I,
0.8
1.0
wants pregnancy
Tot&-relevant. terminations (SE)
0.5
1.5
other medical reasons
l-3
3-l
Removals: pain/bleeding
2.0
3.1
2.5
4.4
Expulsions
0.8
0.3
0.5
2.3
Accidental pregnancy
ML cu250
4.3
TCu
cu7
6 months
84.9
84.8
4273
(1.8)
4288
15.2
(1.8)
1.6
3.4
2.3
4.1
2.3
1.5
71.7
7203
28.3 (2.4)
2.9
5.1
2.6
77.1
7874
22.9 (2.2)
2.1
6.8
2.4
6.1
3.6
6.8
6.1
1.8
TCu
74.4
7808
25.6 (2.3)
2.1
7.4
4-2
6.5
2.8
2.6
ML ~~250
24 months
4.8
ML cu2.50 cu7
15.1
1.3
4.2
0.8
5.1
3.0
0.8
TCu
12 months
NET CUMULATIVE TERMINATION RATES PER 100 WOMEN (N = 1199)
Types of Termination
TABLE V
3
8
CONTRACEPTION No serious or life-threatening complications were encountered. Insertion difficulties were uncommon, probably because our subjects were mostly parous women. We found the ML Cu250 the easiest to insert properly, unlike the TCu-220C and Cu7 which have a more complicated insertion procedure. The simple insertion technique of the ML Cu250 would seem to be a distinct advantage in IUD programs, where relatively inexperienced personnel may be performing the insertions (9); also, since no manipulation of the IUD is needed, the risk of introducing infection at the time of insertion is reduced although in this study, we were unable to demonstrate this advantage. The expulsion rate of the ML Cu250 was the lowest and this is consistent with the hypothesis that its transverse arms provide a fundal-seeking effect (5). the transverse arms of the TCu provide static In contrast, anchorage in-utero whereas the Cu7 does not have such a firm retentive mechanism (1.5). Several factors may be responsible for the different rates of pregnancy failure observed, such as intra-uterine positioning of the device, vector design, area of copper and its disposition on the IUD (10). None of these attributes was studied individually so that it is not However, possible to rank their importance. little difference in pregnancy failure rates has been observed within the range of 200300 mm2 exposed area of copper (10). We might therefore speculate that the high expulsion rate of the Cu7 and the presence of copper on the transverse arms of the TCu-220C are the significant factors underlying their different pregnancy rates. No problems were encountered during removal of all 3 IUDs. However, loss of copper coils was noted on both the ML Cu2.50 and Cu7 devices removed electively at 2 years. This observation does not lend support to the contention that the thicker copper wire on the ML ‘Cu250 ensures a longer life-span in-utero (5). On the other hand, the copper sleeves on the TCu-220C appeared tarnished but grossly intact, a feature which is consistent with its projected life-span (10). In view of the lack of important or statistically significant differences between the ML Cu250 and the TCu-220C, we prefer, on the basis of the use of the ML Cu250 in family planning programs; our experience, and though not significantly different its use-effectiveness is high, of ease of insertion which is from the TCu-220C, has the advantage
82
JANUARY
1983 VOL. 27 NO. 1
CONTRACEPTION crucial if good results are to be consistently achieved. While the TCu-220C may have a greater demographic impact because of its longer life-span (IO), and may be particularly suitable for developing countries where medical and financial resources are limited, it is debatable whether these considerations are relevant in environments where the IUD is used primarily for birth-spacing rather than for family limitation.
Acknowledgements This study was supported by the International Development Research Centre, Ottawa. Our thanks are also due to Miss Verghese, Project Coordinator; Miss Y.M. Yong and Dr. S.C. Alex Lee for statistical analysis, Sister Patricia Mathews and Miss K. Rajeswary.
REFERENCES 1.
Sivin I. & Stern J. Long-acting, more effective Copper-T IUDs: A summary of U.S. experience, 1970-75. Stud. Fam. Plann. 10: 263281 (1979).
2.
Cooper D.L., Millen A.K. & Mishell D.R. The Copper-T-220C: A new long-acting intrauterine contraceptive device. Amer. J. Obstet. Gynaecol. 124: 121-124 (1976).
3.
Van der Pas H. Long-acting intrauterine contraceptive devices. Medicated IUDs and Polymeric Delivery Systems - International Symposium, Amsterdam, Holland, June 27-30, 1979. Abstract No. IS.
4.
Van OS W.A.A., Rhemrev P.E.R., Bomert L. & Aartsen E.J. Experience with a combined multiload contraceptive intrauterine device. 8th World Congress of Fertility & Sterility. Buenos Aires, Nov. 39, 1974.
5.
Thiery M., Van der Pas H., Van OS W.A.A., Tauber P.F. et al. Three years' experience with the ML Cu 250, a new copper-wired ?iti%rterine contraceptive device. Adv. Plann. Parent. Vol. XIII: 35-40 (1978).
JANUARY
1983 VOL. 27 NO. 1
83
CONTRACEPTION
6.
Kho F.H.G., de Bruin A.J.J. & Lips G.L.M. Clinical trial with Multiload Cu 250 IUDs. Medicated IUDs and Polymeric Delivery Systems - International Symposium, Amsterdam, Holland, June 27-30, 1979. Abstract No. 18.
7.
Wilson J. A personal series of Cu7 and ML 250 (ibid). Abstract No. 17.
8.
Barwin B.N. A randomised study of the Multiload 375 and the Copper 7 (ibid).AbstractNo. 13.
9.
Mishell D.R. The clinic factor in evaluatingIUDs. In: Analysis of IntrauterineContraception(HefnawiF. & Segal S.J., Editors) North Holland PublishingCo., Amsterdam1975, p. 27-36.
10.
Tatum H.J. Clinical aspects of intrauterine contraception: Circumspection1976. Fertil. & Steril. 28: 3-28 (1977).
11.
Newton J., Elias J., M&wan J. & Mann G. Intrauterinecontraception with the Copper 7: Evaluation after two years. Br. Med. J. 3: 447-450 (1974).
12.
Tietze C. & Lewit S. Recommendedproceduresfor the statistical evaluation of intrauterine contraception. Stud. Fam. Plann. 4: 35-42 (1973).
13.
Azen S.P., Roy S., Pike M.C. b Casagrande J. Some suggested improvementsto current statisticalmethods of analysing contraceptive efficacy.J. Chron. Dis. 29: 649-666 (1976).
14s
Potter R.G. Use-effectiveness of intrauterine contraception as a problem in competing risks, In: Family Planning in Taiwan (Freedman R. & Takeshita J., Editors). Princeton University Press, Princeton 1969, p. 458-484.
15.
Kamal I. Atlas of HysterographicStudies of the IUD-holding Uterus. International Development Research Centre, Ottawa 1979, pa 42-62.
84
JANUARY 1983 VOL. 27 NO. 1
A RANDOMISED COMPARATIVE EVALUATION OF THE COPPER 7, MULTILOAD COPPER 250 AND T COPPER-220C IUDs
T.H. Goh, T.A. Sinnathuray, V. Sivanesaratnam, & D.K. Sen Department of Obstetrics & Gynaecology, University of Malaya, Kuala Lumpur, Malaysia
L.S. Lim, S.S. Ratnam, S.M.M. Karim & T. McCarthy Department of Obstetrics & Gynaecology, National University of Singapore, Singapore
H. Hutapea, M.J. Hanafiah & P. Simandjuntak Department of Obstetrics & Gynaecology, University of North Sumatra, Medan, Indonesia
ABSTRACT Two new Cu-IlJDs, the TCu-220C and Multiload Cu250, were evaluated against the Cu7 in 1,199 subjects in a randomised, multicentric trial using a common study protocol. During the 2 years following insertion, cumulative first-segment rates for total use-related terminations showed no significant differences between the 3 devices; however, the Cu7 had a significantly higher termination rate for accidental pregnancy compared to the TCu-220C and its expulsion rate was significantly higher than the ML Cu250. The rate of accidental pregnancy was higher and the expulsion rate lower with the ML Cu25O compared to the TCu-220C but these differences were not significant. The results are discussed in relation to IUD design and their application in family planning.
Submitted for publication September 18, 1981 Accepted for publication December 17, 1982
JANUARY
1983 VOL. 27 NO. 1
75
CONTRACEFTION INTXODUCTION
High use-effectiveness in both parous and nulliparous women have been reported with the TCu-220C (1,2,3) and Multiload 250 (ML Cu 250) IUDs (4,5,6). However, comparative studies with the Cu7 (7,8) have not hitherto allowed an objective evaluation of these newer IUDs because many factors that influence IUD performance were not controlled (9). Thus, whether these newer IUDs are better and whether the hypothetical basis for their design are valid have not been adequately tested. In this study the ML Cu 250 and TCu-220C were evaluated using the Cu7 as the standard. In order that a meaningful comparison could be made, the essential criteria as outlined by Mishell were observed (9). The study commenced on 1st April 1975 at three University centres in Kuala Lumpur (Malaysia), Singapore and in Medan (North Sumatra). The cut-off date was Jlst December 1980. The Cu-IUDs are small devices: eact:measures 36 nun in length and is provided with a monofilament tail for retrival. The rationale for the design of the ML Cu 250 (4,s) and the TCu-220C (10) have previously been reported. The Cu7 requires no further introduction, having been extensively tested before.
MATERIALS AND MSTHODS SubSects were only included for study if they satisfied the following criteria: (i) healthy, informed volunteers aged 19-35 years who would rely solely on the Cu-IUD for contraception, (ii) general and pelvic examination revealed no pathology including the Papanicolaou smear, (iii) no less than 4 weeks postabortal and 8 weeks postpartum, (iv) frequently exposed to the risk of pregnancy, i.e. currently cohabiting and had at least one previous pregnancy, and (v) ability to come for follow-up and to complete the menstrual diary card. The standard contraindications to Cu-IUD insertion were followed (LO). The Cu-IUDs were supplied in individual sterile packages. Insertion technique was as previously described for the Cu7 (11); the TCu220C and ML Cu 250 were inserted according to the manufacturers' instructions. The type of IUD inserted leas based on random allocation and only known just prior to insertion. The follow-up examinations
76
JANUARY
1983 VOL. 27 NO. 1
CONTRACEPTION
were scheduled at 6 weeks, 3 months, 6 months, one year and finally at 2 years. Defaulters were traced by means of telephone or mail and home visits carried out if there was no response. Data on the first-segment of IUD use were analysed using the life-table method with definitions as set out by Tietze and Lewit (12). A computer program was used for analysis and differences in gross rates were compared using chi square (12,13,14).A value of p>O.Os is considered not statisticallysignificant. RESULTS There were 1,199 insertions: Singapore 452, Kuala Lumpur 344 and Medan 403. At the cut-off date, 825 (69%) had completed 2 years: 261 with the Cu7, 286 with the TCu-220C and 278 with the ML Cu250. Failure of insertion was encountered in 4 cases: one each with Cu7 and TCu-220C, and two with ML Cu250. The distributionof age, parity and previous contraceptive history in the three Cu-IUD populations are shown in Tables I-III; as expected, no significant differences were observedbetween them. The study population was generally young and of low parity: 840 or 70% were under 30 years old while 58% were of parity O-2. The net and gross cumulative first segment termination rates are presented in Tables IV and V. Significantdifferencesbetween the 3 devices were found only in their rates of expulsionand accidental pregnancy. Exoulsion The Cu7 had the highest expulsion rate and this was significantly higher compared to the ML Cu250 (p < 0.05). The difference between the ML Cu250 and TCu-220C and between the Cu7 and TCu-220C were not significant. AccidentalPregnancy There were 35 accidental pregnancies,all of which were intrauterine; none had a completely expelled IUD while partial expulsion was only found with the Cu7; in most cases, this had not been noticed by the patient. The rate was higher in the Cu7 compared to the TCu-220C (p < 0.05) but the difference between the Cu7 and ML Cu250 did not reach significantlevels.
JANUARY
1983 VOL. 27 NO. 1
CONTRACEPTION
TABLE I
Method
CONTRACEPTIVE HISTORYOF IUD USERS (%)
cu7 N = 398
TCu-220C N = 401
ML cu250 N = 400
None
36.9
32.1
32.0
Pill
21.8
21.1
25.7
Injectables
1.2
0.7
1.0
IUD
9.0
10.2
7.0
21.3
Other More than one
TABLE II
Age Group (years)
9.5
20.9
22.0
14.7
12.2
AGE DISTRIBUTIONOF IUD USERS ($1
cu7
TCu-220C
2.0
2.7
3.3
20 -
27.9
28.2
24.5
25 -
42.0
38.2
41.5
30 -
23.1
24.9
24.8
Under 20
35 -
5.0
5.2
6.0
Unknown
0.0
0.7
0.0
Mean (SE)
78
27.1 (0.2)
27.1 (0.22)
27.4 (0.22)
JANLJARY 1983 VOL. 27 NO. 1
CONTRACEPTION
Other Terminations There were no significant differences between the 3 IUDs in non-userelated terminations and in use-related IUD removals. There were no uterine or cervical perforations and clinically diagnosed pelvic infection was recorded once with each device. Comparison between 3 Centres For the Cu7, TCu-220C and ML Cu250,respectively, no significant differences were found in each category of use-related terminations when the three study centres were compared.
TABLE III
PARITY DISTRIBUTION OF IUD USERS (%I
cu7
TCu-220C
ML cu250
0
6.5
7.4
7.7
1
14.5
15.7
16.2
2
33.4
35.1
35.5
3
23.1
20.1
22.0
Over 3
22.3
21.4
18.5
Parity
Mean (SE)
2.64
(0.08)
2.50
(0.08)
2.44 (0.08)
DISCUSSION In this investigation, the 3 IUDs were tested under identical conditions so that the IUD was the only important variable studied; the success of this approach is reflected in the relative uniformity achieved in the results from the 3 centres and in the distribution of age, parity and contraceptive history among the respective Cu-IUD groups.
JANUARY
1983 VOL. 27 NO. 1
79
CONTRACEPTION
00.
. .
r?o Y
0;;: &d v
hi f 0
80
JANUARY 1983 VOL. 27 NO. 1
1.6
other personal reasons
2243
91.2
2095
86.1
Continuation rate
91.6
2233
78.6
3942
(2.1)
Woman-months
21.4
2.4
3.2
(1.8)
(%
0.8
O-5
2.1
4.2
5.7
3.9
cu7
13.9
(::I,
0.8
1.0
wants pregnancy
Tot&-relevant. terminations (SE)
0.5
1.5
other medical reasons
l-3
3-l
Removals: pain/bleeding
2.0
3.1
2.5
4.4
Expulsions
0.8
0.3
0.5
2.3
Accidental pregnancy
ML cu250
4.3
TCu
cu7
6 months
84.9
84.8
4273
(1.8)
4288
15.2
(1.8)
1.6
3.4
2.3
4.1
2.3
1.5
71.7
7203
28.3 (2.4)
2.9
5.1
2.6
77.1
7874
22.9 (2.2)
2.1
6.8
2.4
6.1
3.6
6.8
6.1
1.8
TCu
74.4
7808
25.6 (2.3)
2.1
7.4
4-2
6.5
2.8
2.6
ML ~~250
24 months
4.8
ML cu2.50 cu7
15.1
1.3
4.2
0.8
5.1
3.0
0.8
TCu
12 months
NET CUMULATIVE TERMINATION RATES PER 100 WOMEN (N = 1199)
Types of Termination
TABLE V
3
8
CONTRACEPTION No serious or life-threatening complications were encountered. Insertion difficulties were uncommon, probably because our subjects were mostly parous women. We found the ML Cu250 the easiest to insert properly, unlike the TCu-220C and Cu7 which have a more complicated insertion procedure. The simple insertion technique of the ML Cu250 would seem to be a distinct advantage in IUD programs, where relatively inexperienced personnel may be performing the insertions (9); also, since no manipulation of the IUD is needed, the risk of introducing infection at the time of insertion is reduced although in this study, we were unable to demonstrate this advantage. The expulsion rate of the ML Cu250 was the lowest and this is consistent with the hypothesis that its transverse arms provide a fundal-seeking effect (5). the transverse arms of the TCu provide static In contrast, anchorage in-utero whereas the Cu7 does not have such a firm retentive mechanism (1.5). Several factors may be responsible for the different rates of pregnancy failure observed, such as intra-uterine positioning of the device, vector design, area of copper and its disposition on the IUD (10). None of these attributes was studied individually so that it is not However, possible to rank their importance. little difference in pregnancy failure rates has been observed within the range of 200300 mm2 exposed area of copper (10). We might therefore speculate that the high expulsion rate of the Cu7 and the presence of copper on the transverse arms of the TCu-220C are the significant factors underlying their different pregnancy rates. No problems were encountered during removal of all 3 IUDs. However, loss of copper coils was noted on both the ML Cu2.50 and Cu7 devices removed electively at 2 years. This observation does not lend support to the contention that the thicker copper wire on the ML ‘Cu250 ensures a longer life-span in-utero (5). On the other hand, the copper sleeves on the TCu-220C appeared tarnished but grossly intact, a feature which is consistent with its projected life-span (10). In view of the lack of important or statistically significant differences between the ML Cu250 and the TCu-220C, we prefer, on the basis of the use of the ML Cu250 in family planning programs; our experience, and though not significantly different its use-effectiveness is high, of ease of insertion which is from the TCu-220C, has the advantage
82
JANUARY
1983 VOL. 27 NO. 1
CONTRACEPTION crucial if good results are to be consistently achieved. While the TCu-220C may have a greater demographic impact because of its longer life-span (IO), and may be particularly suitable for developing countries where medical and financial resources are limited, it is debatable whether these considerations are relevant in environments where the IUD is used primarily for birth-spacing rather than for family limitation.
Acknowledgements This study was supported by the International Development Research Centre, Ottawa. Our thanks are also due to Miss Verghese, Project Coordinator; Miss Y.M. Yong and Dr. S.C. Alex Lee for statistical analysis, Sister Patricia Mathews and Miss K. Rajeswary.
REFERENCES 1.
Sivin I. & Stern J. Long-acting, more effective Copper-T IUDs: A summary of U.S. experience, 1970-75. Stud. Fam. Plann. 10: 263281 (1979).
2.
Cooper D.L., Millen A.K. & Mishell D.R. The Copper-T-220C: A new long-acting intrauterine contraceptive device. Amer. J. Obstet. Gynaecol. 124: 121-124 (1976).
3.
Van der Pas H. Long-acting intrauterine contraceptive devices. Medicated IUDs and Polymeric Delivery Systems - International Symposium, Amsterdam, Holland, June 27-30, 1979. Abstract No. IS.
4.
Van OS W.A.A., Rhemrev P.E.R., Bomert L. & Aartsen E.J. Experience with a combined multiload contraceptive intrauterine device. 8th World Congress of Fertility & Sterility. Buenos Aires, Nov. 39, 1974.
5.
Thiery M., Van der Pas H., Van OS W.A.A., Tauber P.F. et al. Three years' experience with the ML Cu 250, a new copper-wired ?iti%rterine contraceptive device. Adv. Plann. Parent. Vol. XIII: 35-40 (1978).
JANUARY
1983 VOL. 27 NO. 1
83
CONTRACEPTION
6.
Kho F.H.G., de Bruin A.J.J. & Lips G.L.M. Clinical trial with Multiload Cu 250 IUDs. Medicated IUDs and Polymeric Delivery Systems - International Symposium, Amsterdam, Holland, June 27-30, 1979. Abstract No. 18.
7.
Wilson J. A personal series of Cu7 and ML 250 (ibid). Abstract No. 17.
8.
Barwin B.N. A randomised study of the Multiload 375 and the Copper 7 (ibid).AbstractNo. 13.
9.
Mishell D.R. The clinic factor in evaluatingIUDs. In: Analysis of IntrauterineContraception(HefnawiF. & Segal S.J., Editors) North Holland PublishingCo., Amsterdam1975, p. 27-36.
10.
Tatum H.J. Clinical aspects of intrauterine contraception: Circumspection1976. Fertil. & Steril. 28: 3-28 (1977).
11.
Newton J., Elias J., M&wan J. & Mann G. Intrauterinecontraception with the Copper 7: Evaluation after two years. Br. Med. J. 3: 447-450 (1974).
12.
Tietze C. & Lewit S. Recommendedproceduresfor the statistical evaluation of intrauterine contraception. Stud. Fam. Plann. 4: 35-42 (1973).
13.
Azen S.P., Roy S., Pike M.C. b Casagrande J. Some suggested improvementsto current statisticalmethods of analysing contraceptive efficacy.J. Chron. Dis. 29: 649-666 (1976).
14s
Potter R.G. Use-effectiveness of intrauterine contraception as a problem in competing risks, In: Family Planning in Taiwan (Freedman R. & Takeshita J., Editors). Princeton University Press, Princeton 1969, p. 458-484.
15.
Kamal I. Atlas of HysterographicStudies of the IUD-holding Uterus. International Development Research Centre, Ottawa 1979, pa 42-62.
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