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Biomedical subjects

Dan Apter

Publications and source records attributed to Dan Apter.

6 recordsLinked to original sources
PubMed2003

Criteria for selective screening for Chlamydia trachomatis.

BACKGROUND: On the basis of studies in ethnically diverse populations, it appears that the best strategy for prevention of infections is screening of all women aged 25 years or younger. GOAL: The goal was to determine screening criteria in an ethnically and socioeconomically homogenous population with low prevalence of genital chlamydia infection. STUDY DESIGN: Women (N = 1198) attending two family planning clinics were screened for and surveyed for risk factors. Data were analyzed with multivariate logistic regression. RESULTS: The overall prevalence of infection was 3.5%. Risk markers for the infection included marital status, number of sex partners, and age. Screening women aged 25 years or younger would have identified 28% of all chlamydial infections, while screening all women aged 30 years or younger would have identified 83% of infections. CONCLUSION: Because of its feasibility, age appears to still be the best screening criterion. However, extension of the screening to include women up to 30 years of age should be considered.

Adolescent↗
PubMed2002

Low dose mifepristone and two regimens of levonorgestrel for emergency contraception: a WHO multicentre randomised trial.

BACKGROUND: A single 10 mg dose of mifepristone, and two 0.75 mg doses of levonorgestrel 12 h apart, are effective for emergency contraception. Because no studies had compared the efficacies of both compounds, or investigated a single dose of 1.5 mg levonorgestrel, we undertook this three-arm trial. METHODS: We did a randomised, double-blind trial in 15 family-planning clinics in 10 countries. We randomly assigned 4136 healthy women with regular menstrual cycles, who requested emergency contraception within 120 h of one unprotected coitus, to one of three regimens: 10 mg single-dose mifepristone; 1.5 mg single-dose levonorgestrel; or two doses of 0.75 mg levonorgestrel given 12 h apart. The primary outcome was unintended pregnancy; other outcomes were side-effects and timing of next menstruation. Analysis was by intention to treat, but we did exclude some patients from the final analyses. FINDINGS: Of 4071 women with known outcome, pregnancy rates were 1.5% (21/1359) in those given mifepristone, 1.5% (20/1356) in those assigned single-dose levonorgestrel, and 1.8% (24/1356) in women assigned two-dose levonorgestrel. These proportions did not differ significantly (p=0.83). The relative risk of pregnancy for single-dose levonorgestrel compared with two-dose levonorgestrel was 0.83 (95% CI 0.46-1.50), and that for levonorgestrel (the two regimens combined) compared with mifepristone, 1.05 (0.63-1.76). Side-effects were mild and did not differ greatly between groups, and most women menstruated within 2 days of the expected date. Women who took levonorgestrel had earlier menses than did those who took mifepristone. INTERPRETATION: The three regimens studied are very efficacious for emergency contraception and prevent a high proportion of pregnancies if taken within 5 days of unprotected coitus. Mifepristone and levonorgestrel do not differ in efficacy. A 1.5 mg single levonorgestrel dose can substitute two 0.75 mg doses 12 h apart.

Adult↗
PubMed2002

Oral contraceptive use before first birth and risk of breast cancer: a case control study.

BACKGROUND: The aim of this study was first, to investigate whether women starting oral contraceptive (OC) use at a young age and before first birth have an increased risk for breast cancer and second, to report difficulties encountered in studying long-term health impacts of medical technologies. METHODS: Breast cancers occurring up until 1997 among 37153 Helsinki students born between 1946 and 1960 were identified by record linkage from the Finnish Cancer Registry; for each cancer case, five age-matched random controls were picked from the same student population. Those who had used the Helsinki Student Health Service (HSHS) at least three times (150 cases and 316 controls) form the final study subjects. Data on OC use and background characteristics were collected from patient records, and data on live births were derived from the population register. Odds ratios (OR) were adjusted for number of births, smoking and sports activity. RESULTS: Compared to the few non-users, OC users had a higher risk of breast cancer: the adjusted OR was 2.1 (95% confidence interval 1.1-4.2). Among OC users, no statistically significant differences in risk of breast cancer were found in regard to starting age or first birth, but small numbers made confidence intervals wide. Even though we had chosen students to be our study group, the population turned out to be unsuitable to answer our research question: most women had started their OC use old (at the age of 20 or later) and there were very few unexposed (almost all had used OC and before their first birth). CONCLUSIONS: Because adoption of the modern pattern of OC use was not common among students, it is unlikely that the impact of early and extended OC use can be studied before 2010, when women born in the 1960s are 40 to 50 years old.

Journal Article↗
PubMed2002

Efficacy, cycle control, and user acceptability of a novel combined contraceptive vaginal ring.

OBJECTIVE: To assess the contraceptive efficacy, cycle control, tolerability, and user acceptability of a novel combined contraceptive vaginal ring for up to 13 cycles. METHODS: Healthy women requesting contraception were enrolled in this 1-year multicenter study. Each ring released 120 microg of etonogestrel and 15 microg of ethinylestradiol daily, and was used for 3 weeks followed by a 1-week ring-free period. RESULTS: A total of 2322 women started treatment and so formed the intent-to-treat population. Subjects were followed for 23,298 cycles, equivalent to 1786 woman-years. Compliance was good with 85.6% of cycles in full compliance with specified criteria. In the intent-to-treat population, 21 pregnancies occurred, giving a Pearl Index of 1.18 (95% confidence interval 0.73, 1.80). Eleven of the pregnancies were attributable to noncompliance; the Pearl Index for the per-protocol population was 0.77 (95% confidence interval 0.37, 1.40). The mean incidence of withdrawal bleeding was 98.5% in all cycles. Irregular bleeding occurred in 5.5% of all cycles, and in most women, early or late withdrawal bleeding was restricted to spotting. The ring was well tolerated with a low incidence of adverse events; only 2.5% of all discontinuations were device related. The ring was easy to insert and remove and did not interfere with intercourse. Eighty-five percent of women were satisfied with the ring, and 90% would recommend its use to others. CONCLUSION: The ring is an effective contraceptive with excellent cycle control that is convenient, well tolerated, and highly acceptable to users.

Adolescent↗
PubMed2002

Update on female pubertal development.

PURPOSE OF REVIEW: To elucidate recent findings regarding female puberty. The successful completion of puberty is a prerequisite for reproduction. Many later disorders of fertility and metabolism may develop during puberty. New more sensitive and specific assays provided us with possibilities for a better understanding of the process of puberty, and the discovery of new factors such as leptin evoked the hope of finding key regulators of the onset of puberty. RECENT FINDINGS: The secular trend towards earlier menarche appears now to have come to an end, but discussions about changes in the age of pubertal onset still continue. In a few detected cases of leptin mutations puberty has not occurred spontaneously. The intact secretion of leptin seems to be a necessary prerequisite for the onset of puberty. Apart from that, recent research has indicated that leptin levels mainly reflect body composition. Leptin as well as gonadotropins, steroids and growth hormone shows specific circadian patterns. The 24 h pattern of leptin is similar before and after puberty, but the 24 h pattern of the other hormones changes. The serum concentration of inhibin B increases in the years preceding puberty and in early puberty, whereas inhibin A increases in mid to late puberty. SUMMARY: The biological significance of the changing circadian patterns remains to be determined. Inhibin B serum concentrations together with follicle-stimulating hormone may indicate remaining potential ovarian activity during childhood in, for example, patients with Turner syndrome, but more information and other possible markers are needed.

Adolescent↗