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Biomedical subjects

I Sivin

Publications and source records attributed to I Sivin.

At least 19 recordsLinked to original sources
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↗
PubMed1990

A randomized trial of the Gyne T 380 and Gyne T 380 Slimline Intrauterine Copper devices.

To facilitate manufacture and insertion of the Gyne T 380 IUD, design changes were instituted. Copper collars were seated flush at the ends of the horizontal crossbar of the device. A randomized study of the Gyne T 380 Slimline, the new design, was undertaken in comparison with the standard Gyne T 380. A total of 996 women were enrolled, with 698 Slimline insertions and 298 of the standard Gyne T. No statistically significant difference in ease of insertion or in performance was detected between the models. At one year, the pregnancy rate of each model was below 0.5 per 100 and the continuation rate was 79-80 per 100. Pelvic inflammatory disease or endometritis was found in one percent of subjects in the first year. This is the seventh multicenter randomized study of a collared T IUD with 380 mm2 of copper surface. In all seven, the one-year gross pregnancy rate has been 1.2 per 100 or lower.

Adult↗
PubMed1990

Clinical assessment of treatments for prolonged bleeding in users of Norplant implants.

The effectiveness of three drugs in controlling prolonged bleeding in the first year of NORPLANT implants use was tested. The drugs were levonorgestrel (L-Ng, 0.03 mg twice a day for 20 days), ethinylestradiol (EE, 0.05 mg per day for 20 days) and ibuprofen (Ib, 800 mg three times a day for 5 days) and were given orally. A control group received a placebo (PL, one pill of lactose for 20 days). Treatment should start each time a woman experienced eight consecutive days of bleeding or spotting. The 183 volunteers were not aware of the drug administered. A daily record of bleeding and spotting and of treatment intake was maintained. One-hundred-forty women completed the study period; 60 never used the prescribed treatment. Women treated with the three test drugs had significantly fewer bleeding and spotting days during the treated month and also throughout the study year than women using the placebo. The mean number of bleeding plus spotting days per actually treated subject in the first year was 77, 94, 101 and 129 days for the EE, Ib, L-Ng and PL groups, respectively. The administration of EE might help in the management of prolonged bleeding during the first year of NORPLANT implants use.

Administration, Oral↗
PubMed1979

A randomized double blind study of two oral contraceptives.

To study the question of whether one brand of oral contraceptives may be as acceptable as another for use of publicly-assisted family planning programs, a double blind study of two well-known brands, Ovral and Norinyl, was undertaken in Costa Rica and Trinidad. The pills were randomly assigned to 1,200 women. Common side effects - nausea, dizziness, vomiting, headaches - were associated with both Norinyl and Ovral. Differences in event rates for these conditions were much more marked by country than by the pill used. Ovral was associated with increases in skin problems, notably chloasma, in Cost Rica. A higher percentage of women using Norinyl reported intermenstrual bleeding and spotting in both countries. In Costa Rica continuation rates for Norinyl were adversely affected by this. With these exceptions there appear to be no important differences between the brands that would affect their use in family planning programs.

Adolescent↗
PubMed1979

Copper T IUD use and ectopic pregnancy rates in the United States.

Over a four-year exposure period, the rate of ectopic pregnancy for women using a Copper T IUD was less than 1 per 1000 years of use. The cumulative 4-year probability of having an ectopic pregnancy while using the Copper T was 4 per 1000 women. These results are based on a study of 35,496 women with 38,064 years of use. Data on ectopic pregnancies in the United States provide a basis with which IUD experience may be compared. The National Hospital Discharge Survey shows a doubling in the number of ectopic pregnancies and in the incidence rates between 1965 and 1976. The relative risk of ectopic pregnancy among IUD users as compared with sexually active women not using the pill or sterilization may have been above 1 in 1965. In 1976, the relative risk is estimated to have been below 1. Compared with all woman-years of exposure, including women using contraceptive sterilization and the pill, the relative risk of extopic pregnancy to IUD users in 1976 was about 1. The IUD could not have been a major factor contributing to the recent doubling in the rate of ectopic pregnancy in the U.S.

Adult↗
PubMed1978

Long acting contraceptive implants. An analysis of menstrual bleeding patterns.

The menstrual patterns of women using subdermal implants of levonorgestrel and norgestrienone included in a double-blind clinical trial was evaluated by the method developed by the International Committee on Contraception Research. Women using Copper T200 randomly selected in the same clinics were used as controls. Both implant regimens were associated with a high frequency of reduced bleeding and norgestrel patients had also a high proportion of increased and irregular bleeding. Termination of use was associated to increased bleeding but not so much to reduced bleeding.

Adolescent↗