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Biomedical subjects

I Sivin

Publications and source records attributed to I Sivin.

At least 37 records · Page 2Linked to original sources
PubMed1994

A five-year evaluation of NORPLANT II implants in China.

A five-year study of NORPLANT II rod implants was undertaken in four large cities and metropolitan areas in eastern China. Designed to test the safety, efficacy and acceptability of these implants, the study involved 1,208 women and was conducted concurrently with a similar study of NORPLANT capsule implants. At the end of five years, the gross pregnancy rate was 0.65 per 100, and the continuation rate was 65.3 per 100. Both these values were similar to and not statistically different from the rates of the capsule implant users. In 4,828 woman-years of use, there were few severe adverse events reported. Users and providers found the method to be an acceptable long-term contraceptive method of great reliability.

Adult↗
PubMed1994

Health during prolonged use of levonorgestrel 20 micrograms/d and the copper TCu 380Ag intrauterine contraceptive devices: a multicenter study. International Committee for Contraception Research (ICCR).

OBJECTIVES: To measure and compare the incidence of adverse events during use of two medicated intrauterine devices (IUDs). DESIGN: A multicenter prospective 7-year randomized study. SETTING: Family planning clinics, primarily in developing countries. SUBJECTS: Women age 18 to 38 years at admission, desiring contraception and without contraindications to IUDs. MAIN OUTCOME MEASURES: Incidence of complaints, conditions, and rates of specific termination for each IUD. METHODS: Subjects recorded menstrual events, and clinical staff registered all complaints and conditions found on examination at four first-year clinic visits and at semiannual visits thereafter. Difference in rates were analyzed by chi 2 statistics. RESULTS: Annual pregnancy rates for each IUD averaged 0.2/100 women whereas upper genital tract infection occurred at rates of 0.6 to 0.7 per 100 years of use. The levonorgestrel-releasing IUD significantly decreased bleeding and spotting days in comparison with historical data for noncontraceptors and with the copper-medicated IUD. Dysmenorrhea, vaginitis, and myoma in women with the levonorgestrel IUD were markedly decreased in comparison with the experience of copper IUD users. Significantly higher rates of amenorrhea, delayed ovarian follicular atresia, skin and hair conditions, and headache were observed with the steroid IUD than with the copper-releasing IUD. Rates of reported adverse effects for either IUD were highest in the first 2 years of use and among women under age 25. CONCLUSIONS: Long-term use of copper or levonorgestrel IUDs is characterized by very low rates of pregnancy and by a low and declining annual incidence of side effects, including pelvic infection and borderline anemia. The levonorgestrel-releasing IUD reduced the incidence of bleeding and, in the long term, of myoma and myoma-related surgery in comparison with the copper T IUD. Both IUDs proved highly acceptable and had few unanticipated side effects.

Adolescent↗
PubMed1994

Contraception with NORPLANT implants.

NORPLANT progestogen-only implant contraception provides several years of effective protection against pregnancy following a single application. It is reversible whenever desired, with return to normal fertility. Drug release and concentrations are maximal in the first month of use, when a set of six capsules releases approximately 85 micrograms/day of levonorgestrel. Release is 25-30 micrograms/day at 60 months. Circulating drug concentrations and pregnancy rates vary inversely with body weight at placement, but even among heavier women, failure rates are below those of oral contraceptives in the general population. Side-effects are most marked at the initiation of use. Disruption of normal menstrual patterns occurs in 70-80% of recipients initially. Menstrual blood loss is decreased, however, and most women experience modest increases in haemoglobin. Headache, acne, other skin or hair problems, changes of weight and of mood and abdominal pain, are the most common side-effects attributed to NORPLANT contraception. The frequency of occurrence of side-effects diminishes with increased duration of use. The comparative paucity of major side-effects, coupled with the method's convenience and effectiveness and its very long action have made NORPLANT implants highly acceptable in both developing and developed countries.

Contraceptive Agents, Female↗
PubMed1994

A 5-year evaluation of NORPLANT contraceptive implants in China.

OBJECTIVE: To assess the efficacy, safety, and acceptability of NORPLANT implants when used by Chinese women. METHODS: In a prospective, multicenter clinical trial, 10,718 women selecting NORPLANT implants were monitored semiannually for the first 2 study years and then annually through 5 years. Life table rates of pregnancy and other terminations were calculated, as were incidence rates of serious conditions leading to termination. RESULTS: The 5-year average annual pregnancy rate was 0.3 per 100 and the ectopic pregnancy rate was minimal, 0.09 per 1000 woman-years. Pregnancy rates correlated significantly with weight, but regardless of weight group, annual average pregnancy rates were less than one per 100. Younger women experienced higher pregnancy rates than did older users. Headache, myoma, dizziness, and weight gain led more frequently to termination than did other adverse events apart from menstrual disturbances. Mortality during use was 2.0 per 10,000 years, based on 44,954 years of experience. There were no cardiovascular or cerebrovascular deaths, and no deaths were attributable to NORPLANT use. Seventy-two per 100 initial acceptors used the implants continuously for 5 years. CONCLUSION: NORPLANT implants proved highly effective, safe, and acceptable among Chinese women regardless of province, age, or weight at admission.

Adult↗
PubMed1993

Another look at the Dalkon Shield: meta-analysis underscores its problems.

Numerous non-comparative clinical trials of the Dalkon Shield appear to provide ample evidence that the Dalkon Shield was an effective IUD; they seem to yield little evidence that it was a dangerous device, nor markedly different from its contemporaries. Equating the performance of the Dalkon Shield IUD to that of the Lippes Loop or of Copper IUDs is erroneous, however, with respect to rates of pregnancy, expulsion, pelvic infection, septic abortion, death with the device in situ, and tubal infertility. Randomized studies show the Dalkon Shield had approximately double the pregnancy rates of the Lippes Loop D or Copper IUDs (P < .05) and a significantly lower expulsion rate. These differences coupled together with the distinguishing multifilament tail of the Dalkon Shield underlay the higher rates of pregnancy complications, including septic abortions with the device in situ and deaths, associated with the Shield. A five-fold increased risk of hospitalized pelvic infection among Dalkon Shield users found in the Women's Health Study resulted not from ascertainment bias, but was related to the fact that Dalkon Shield users had more severe hospitalized PID than did other hospitalized women with PID and IUD use. Following cessation of distribution and of use of the Dalkon Shield, and following the FDA's recommendation to remove IUDs in case of pregnancy, there have been no deaths reported among pregnant American women with an IUD in situ in a 15-year period. Neither the IUDs of today nor those in use during 1970-1974 are equitable to the Dalkon Shield [corrected].

Case-Control Studies↗
PubMed1993

Four-year experience in a randomized study of the Gyne T 380 Slimline and the Standard Gyne T 380 intrauterine copper devices.

Performance of the Slimline and Standard models of the Gyne T 380 were measured through four years in a comparative study initially involving 996 women, seventy percent of whom were randomized to the Slimline device. Cumulative pregnancy rates of Slimline users were 0.3 +/- 0.2 per 100 both at three and at four years, as compared with rates of 1.5 +/- 0.9 and 3.8 +/- 1.7 at the same intervals for users of the Standard model (P > .05). The four-year explusion rate of the Slimline, 8.6 +/- 1.3 per 100, was significantly higher than the comparable rate of the Standard model, 4.4 +/- 1.6 (P < .05). The two Gyne T* models did not differ in continuation rates. First time IUD users, however, had substantially lower continuation rates than did former users (P < .001), in consequence of their relative youth and desire to have additional children. Other performance measures did not differ importantly by device.

Adolescent↗
PubMed1992

Rates and outcomes of planned pregnancy after use of Norplant capsules, Norplant II rods, or levonorgestrel-releasing or copper TCu 380Ag intrauterine contraceptive devices.

OBJECTIVES: The objectives were to measure rates of planned pregnancy and factors affecting these rates after use of very-long-acting contraceptive methods (Norplant or Norplant II implants, a levonorgestrel-releasing intrauterine contraceptive device, or the copper T (model TCu 380Ag) intrauterine contraceptive device. STUDY DESIGN: The design was a concurrent, multicenter prospective study of 372 women who stopped contraception for planned pregnancy. Analysis was by life-table, log-rank, and standard chi 2 methods. RESULTS: Pregnancy rates 12 and 24 months after cessation of contraceptive use were 82 and 89 per 100, respectively. Age at removal and family planning intentions at initiation of contraception were both significantly correlated with pregnancy rates (p less than 0.05), but former contraceptive regimen and duration of contraceptive use were not. Pregnancy outcomes did not deviate from normal limits and did not differ by contraceptive formerly used. CONCLUSION: Contraceptive implants releasing 30 micrograms/day of levonorgestrel or intrauterine contraceptive devices releasing 20 micrograms/day of levonorgestrel or having copper surface areas of 380 mm2 are associated with normal fertility after use for women seeking pregnancy at termination. Durations of use do not affect pregnancy rates.

Adult↗
PubMed1991

Prolonged intrauterine contraception: a seven-year randomized study of the levonorgestrel 20 mcg/day (LNg 20) and the Copper T380 Ag IUDS.

A levonorgestrel-releasing IUD and the Copper T 380Ag IUD were in randomized comparison for seven years in five clinics. In two other clinics the randomized 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 randomized trials.

Adolescent↗
PubMed1991

Two-year comparative trial of the Gyne T* 380 Slimline and Gyne T* 380 intrauterine copper devices.

In a randomized trial of the Gyne T* 380 Slimline, the-two year pregnancy rate was 0.3 per 100 and the continuation rate was 65 per 100. These rates did not differ statistically from those of the standard Gyne T* 380, nor did other performance parameters differ between devices by the log-rank test. Women under age 30 had lower continuation rates using either device than did women age 30 or older at admission because of removals for planned pregnancy. Conception rates among those who desired pregnancy were 35 per 100 at one month and 86 per 100 at one year.

Adult↗
PubMed1991

Dose- and age-dependent ectopic pregnancy risks with intrauterine contraception.

Analyses of randomized trials of copper intrauterine devices (IUDs) substantiate three hypotheses: 1) Ratios of ectopic to total pregnancies conceived during copper IUD use did not differ among devices; 2) pregnancy rates per 1000 woman-years varied inversely with copper surface area; and 3) ectopic pregnancy rates consequently varied inversely by copper surface area. Randomized trials also demonstrated that progestin-only IUDs had a markedly higher ratio of ectopic to total pregnancies, 171 per 1000, than did copper IUDs, at 39 per 1000 (P less than .001). Ectopic pregnancy rates per 1000 woman-years with progestin-only IUDs varied inversely with dose, notably for levonorgestrel-releasing devices. In a large United States IUD cohort study, ectopic pregnancy ratios of copper IUDs varied significantly (P less than .05) with age, as they do in the general population. Copper and non-medicated IUDs in the United States and the United Kingdom had age-specific ectopic pregnancy ratios six times those of non-contraceptors in the United States population during 1970-1978. The estimated rate of ectopic pregnancy for users of IUDs having 200 mm2 of copper was four-tenths that of non-contraceptors in the United States during 1970-1978. For users of devices with 350 mm2 or more of copper, ectopic pregnancy rates were one-tenth those of non-contraceptors. Rates for users of devices releasing 65 micrograms/day of progesterone are estimated to have been 50-80% above those of non-contraceptors. Devices releasing 20 micrograms/day of levonorgestrel have had ectopic pregnancy rates estimated to be 0.1 of those of non-contraceptors. Most IUDs protect against ectopic pregnancy.

Age Factors↗
PubMed1990

Long-term contraception with the levonorgestrel 20 mcg/day (LNg 20) and the copper T 380Ag intrauterine devices: a five-year randomized study.

An intrauterine device, releasing approximately 20 micrograms/day of levonorgestrel (LNg 20), used by 1124 women, was studied in a randomized 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 randomized to the LNg 20 device (P less than .001). Terminations attributed to amenorrhea with the LNg device primarily account for differences in continuation. These two intrauterine devices are the most effective long-term, reversible IUDs yet reported in the literature. No other contraceptive methods have exhibited such low long-term pregnancy rates in randomized comparative trials.

Adolescent↗