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Featured researches published by Francisco Alvarez.


Contraception | 1991

PROLONGED INTRAUTERINE CONTRACEPTION: A SEVEN-YEAR RANDOMIZED STUDY OF THE LEVONORGESTREL 20 mcg/DAY (LNg 20) AND THE COPPER T380 Ag IUDS

Irving Sivin; Janet Stern; Elsimar M. Coutinho; Carlos E.R. Mattos; Sayed El Mahgoub; Soledad Diaz; Margarita Pavez; Francisco Alvarez; Vivian Brache; Francisco Thevenin; Juan Diaz; Anibal Faundes; Margarita Díaz; Terence McCarthy; Daniel R. Mishell; Donna Shoupe

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.


Contraception | 1990

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

Irving Sivin; Sayed El Mahgoub; Terence McCarthy; Daniel R. Mishell; Donna Shoupe; Francisco Alvarez; Vivian Brache; Elvira Jimenez; Juan Diaz; Anibal Faundes; Margarita Díaz; Elsimar M. Coutinho; Carlos E.R. Mattos; Soledad Diaz; Margarita Pavez; Janet Stern

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.


Contraception | 1985

ANOVULATION, INADEQUATE LUTEAL PHASE AND POOR SPERM PENETRATION IN CERVICAL MUCUS DURING PROLONGED USE OF NORPLANTR IMPLANTS

Vivian Brache; Anibal Faundes; E. D. B. Johansson; Francisco Alvarez

Blood samples for progesterone assay were collected for a total of 49 cycles, from 27 volunteers using the NORPLANT system. Levonorgestrel determinations were carried out in the same samples. A group of 12 women with normal cycles were studied in the same manner to serve as controls. Of the 49 cycles studied, 20 (41%) were ovulatory. The mean levonorgestrel level in ovulatory patients was 0.34 +/- 0.11 ng/ml (S.D.) compared to 0.42 +/- 0.14 ng/ml (S.D.) in anovulatory cycles. Compared to the control group, progesterone levels were significantly lower for users of NORPLANT implants during days -12 to -10 (p less than 0.025), -9 to -7 (p less than 0.05), -6 to -4 (p less than 0.0005) and days -3 to -1 (p less than 0.01). Cervical mucus evaluations and post-coital tests were done around mid-cycle in 29 of the cycles studied. All samples of cervical mucus were of poor quality, viscous and scarce, with a mean SPK of 4.1 +/- 2.3 cm. Most had absent or atypical ferning. Twenty-one subjects (73%) had a post-coital score of 1, and 4 (14%) of zero. Thus, anovulation, inadequate luteal phase and the direct effect of the continuous administration of levonorgestrel over cervical function, all seem to contribute to the effectiveness of NORPLANT implants.


American Journal of Obstetrics and Gynecology | 1992

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

Irving Sivin; Janet Stern; Soledad Diaz; Margarita Pavez; Francisco Alvarez; Vivian Brache; Daniel R. Mishell; Maria Lacarra; Terence McCarthy; Pentti Holma; Philip D. Darney; Cynthia Klaisle; Sven-Eric Olsson; Viveca Odlind

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.


Contraception | 1984

Intrauterine contraception with copper and with levonorgestrel: A randomized study of the TCu 380Ag and levonorgestrel 20 mcg/day devices

Irving Sivin; Francisco Alvarez; Juan Diaz; Soledad Diaz; Sayed El Mahgoub; Elsimar M. Coutinho; Vivian Brache; Margarita Díaz; Anibal Faundes; Margarita Pavez; Carlos E.R. Mattos; Janet Stern

First year results of a randomized study of 1509 users of the Copper T380Ag with a silver core or of an IUD releasing 20 mcg day of levonorgestrel are reported. The cumulative gross pregnancy rate for each device was 0.3 per 100 at one year, with more than 490 women having one year of use with each device. The levonorgestrel-releasing device was associated with significantly fewer bleeding days and significantly increased hemoglobin levels when compared with pre-admission values or the one year values observed among users of the TCu380Ag. Terminations attributable to amenorrhea were significantly more frequent among users of the levonorgestrel-releasing device. The TCu 380Ag was associated with increased frequency and severity of dysmenorrhea compared with pre-admission levels or with the steroid-releasing device. Hemoglobin levels were somewhat reduced among users of the TCu 380Ag device. Terminations attributable to pain were, however, not significantly different by device. Continuation rates at the end of the first year were not significantly different by device.


Contraception | 1986

Recovery of fertility after use of the levonorgestrel 20 mcg/d or Copper T 380 Ag intrauterine device.

Hedia Belhadj; Irving Sivin; Soledad Diaz; Margarita Pavez; Ana-Sofia Tejada; Vivian Brache; Francisco Alvarez; Donna Shoupe; Harlene Breaux; Daniel R. Mishell; Terry McCarthy; Veronica Yo

Following use of either the Levonorgestrel 20 mcg/day or the TCu 380 Ag IUD in a randomized comparative study, 110 women stopped contracepting to have planned pregnancies. Pregnancy rates and recovery of fertility have been assessed. Age at acceptance, duration of use, parity and intervals between last pregnancy and IUD insertion or removal were similar for both groups. Life table pregnancy rates at one year were higher than 90 per cent for both device groups; but because some women quickly changed their minds or had been at risk of pregnancy only a short time before the analysis date, only 60.9 percent had actually become pregnant. Median time to planned pregnancy was 3 months for the TCu 380 Ag group and 4 months for the Levonorgestrel 20 group. Neither duration of use nor age at insertion or age at termination affected the pregnancy rates significantly.


Contraception | 1997

Contraceptives for lactating women: A comparative trial of a progesterone-releasing vaginal ring and the Copper T 380A IUD

Irving Sivin; Soledad Diaz; Horacio B. Croxatto; P. Miranda; Mamdouh M. Shaaban; Ezzat H. Sayed; Bilian Xiao; Shang-Chun Wu; Mingkun Du; Francisco Alvarez; Vivian Brache; Sriani Basnayake; Terry McCarthy; Maria Lacarra; Daniel R. Mishell; Suporn Koetsawang; Janet Stern; Theodore M. Jackanicz

From approximately one week before normal ovulation resumes, lactating women require protection against pregnancy by a contraceptive that is safe for both infant and mother in a multicenter one-year study, the natural hormone, progesterone, delivered vaginally by a sequence of four contraceptive rings designed for continuous use, was evaluated as a contraceptive for nursing mothers in comparison with the Copper T 380A IUD. Individual rings release in effective average dose of 10 mg day for a 3 month period. Evaluation included measures of lactational performance as well as of contraceptive efficacy and safety to mother and child. Nine participating clinics enrolled 802 ring users and 734 IUD acceptors between postpartum days 29 and 63. Life table analyses were performed with parallel decrements for ring and IUD subjects. Continuation in the study and analysis required that subjects not stop breastfeeding. The ring, with a one-year pregnancy rate of 1.5 per 100, did not differ significantly from the IUD with respect to contraceptive effectiveness (p > 0.05). More than half of the ring subjects were continuing at 6 months post admission and a quarter (23.5 per hundred) were still using the ring and breastfeeding one year after admission. Women with the IUD, however, had higher continuation rates (p < 0.001) at both time points. The largest single decrement for each method was that for weaning. Ring users had more complaints of vaginal problems but had fewer vaginal disorders on examination. At 12 months postpartum, 46 per 100 continuing ring users remained in amenorrhea. Lactation performance and the health and weight gain of the infants were similar among users of either regimen.


Contraception | 1987

Two years of intrauterine contraception with levonorgestrel and with copper: A randomized comparison of the TCu 380Ag and levonorgestrel 20 mcg/day device

Irving Sivin; Janet Stern; Juan Diaz; Margarita Díaz; Anibal Faundes; Sayed El Mahgoub; Soledad Diaz; Margarita Pavez; Elsimar M. Coutinho; Carlos E.R. Mattos; Terry McCarthy; Daniel R. Mishell; Donna Shoupe; Francisco Alvarez; Vivian Brache; Elvira Jimenez

IUDs releasing 20 mcg/day of levonorgestrel (LNg20) were in randomized 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).


Studies in Family Planning | 1990

Assessing the acceptability of NORPLANT implants in four countries: findings from focus group research.

Zimmerman M; Haffey J; Crane E; Szumowski D; Francisco Alvarez; Bhiromrut P; Brache; Lubis F; M. Salah; Mamdouh M. Shaaban

In 1986-87, a qualitative research project was conducted in the Dominican Republic, Egypt, Indonesia, and Thailand to expand understanding of the acceptability of NORPLANT contraceptive implants beyond inferences made on the basis of continuation rates. In each of the four study sites, focus group discussions or in-depth interviews were held with potential acceptors, current NORPLANT users, discontinuers, husbands of women in these three groups, and service providers. Nonclinical participants generally had little formal education and lived primarily in urban or semi-urban areas where NORPLANT has been available for at least five years. The study focused on attitudes, perceptions, and experiences of each group regarding NORPLANT implants. Results suggest that factors having an impact on the acceptability of NORPLANT implants fall into three general categories: medical/technical, cultural/religious, and informational/educational. This article discusses each of these categories, including programmatic implications of the findings, and puts forward recommendations for enhancing NORPLANT introduction efforts on the basis of these findings.


Contraception | 2001

Levonorgestrel concentrations during 7 years of continuous use of Jadelle contraceptive implants.

Irving Sivin; Livia Wan; Sirpa Ranta; Francisco Alvarez; Vivian Brache; Daniel R. Mishell; Philip D. Darney; Arijit Biswas; Soledad Diaz; Orawan Kiriwat; Manee Piya Anant; Cynthia Klaisle; Margarita Pavez; Janet Schechter

Serum levonorgestrel concentrations were assayed in a multicenter, 7-year study of 199 users of Jadelle rod implants. We examined drug levels, patterns of changes, factors affecting drug levels, and concentrations at which pregnancies occurred. Mean levonorgestrel concentrations declined from 435 pg/mL at 1 month of use to 64% of that value (280 pg/mL) at the end of 3 years. Between the end of the third and fifth years neither mean nor median serum levels varied markedly. At 5 years the mean concentration was again 64% of the first months mean. Declining levels were observed thereafter through the end of 7 years when the mean, 224 pg/mL, was 52% of the 1-month value. Last measured drug concentrations of women who became pregnant during Jadelle use had mean and median values of 152 and 144 pg/mL, respectively, and a maximum value of 180 pg/mL. Analyses indicated ponderal index, body weight, duration of use, and a single clinical center were the most important variables affecting measured levonorgestrel levels. Approximately one-third of assays in the sixth and seventh years were found to be below 180 pg/mL, suggesting that Jadelle levonorgestrel implants would not maintain sufficiently high levels of effectiveness against pregnancy after 5 years and that heavier women would then be at greater risk of pregnancy.

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Anibal Faundes

State University of Campinas

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Daniel R. Mishell

University of Southern California

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Leila Cochon

State University of Campinas

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