Contraception
-
The relationship between the use of barrier contraception methods and the risk of cervical neoplasia was analyzed using data from a case-control study conducted in the greater Milan area, northern Italy. A total of 367 cases of invasive cancer under 60 years of age were compared with 323 subjects in hospital for acute conditions unrelated to any of the established or suspected risk factors for cervical cancer, and 316 cases of cervical intraepithelial neoplasia were compared with 258 outpatient controls. Ever-use of barrier methods (condom and diaphragm) was reported by 6% of the cases of invasive cancer and 12% of hospital controls. ⋯ Considering the total use of barrier methods, compared to never use, the relative risk of invasive cervical cancer was 0.4 (95% confidence interval 0.2-0.9) and decreased with duration of use (chi 2(1), trend = 5.18, p = 0.02). Likewise, use of barrier methods lowered the risk of intraepithelial neoplasia; the estimated relative risks were 0.9 in users for less than two years and 0.6 for two or more (chi 2(1), trend = 4.61, p = 0.03). Although the protection for invasive cancer appeared to be greater at older ages and in multiparous women, the relative risks were not significantly heterogeneous in various strata of parity, number of sexual partners, oral contraceptive use and history of Pap smears.
-
The BIOSELF 110 is a hand-held, non-invasive electronic instrument that measures basal body temperature and cycle length, and automatically identifies the fertile and infertile phases of the menstrual cycle with flashing red light and green light signals, respectively. The device was evaluated in 77 cycles from 33 ovulatory women in Kuala Lumpur, Malaysia. Ultrasound monitoring of maximum follicular diameter (MFD) and urinary LH measurements with Ovustick were used as reference methods to estimate the time of ovulation and the fertile period. ⋯ The mean interval from the onset of the fertile period (first flashing red light day) to the MFD day was 6.9 days (SD 2.6), and from the MFD day to the end of the fertile period, 3.1 days (SD 2.2). The BIOSELF 110 showed itself to be a reliable device for identifying the fertile and infertile phases of the menstrual cycle and, thus, should be a useful aid for couples seeking pregnancy. Prospective clinical trials are underway to assess the contraceptive effectiveness of the device.
-
Clinical Trial
Vaginal bleeding patterns among women using one natural and eight hormonal methods of contraception.
Menstrual diary records were obtained from a total of 5257 women using nine different methods of contraception, one natural and eight hormonal. This paper presents a comparative analysis of their vaginal bleeding patterns. The analytic procedures follow the recommendations of a recent WHO workshop on bleeding pattern analysis, which involve dividing each subject's diary into successive 90-day reference periods, calculating ten indices for each period, and classifying women according to whether they have "clinically important" bleeding disturbances. ⋯ The incidence of amenorrhea rose from just under 10% in their first injection interval to over 40% in their fourth. The methods of analysis recommended by WHO in 1985 still require substantial refinement. Nevertheless, they are more sensitive than those used previously for WHO trials and produce an easily understood, clinically meaningful characterization of bleeding patterns.
-
A microcomputer software was developed to analyse menstrual diaries following the reference period method as described in the article "The analysis of vaginal bleeding patterns induced by fertility regulating methods" published in this journal (Contraception, 34:253-260, 1986). The programme allows the analysis of groups of diaries selected according to subjects' characteristics recorded at commencement of the diary. ⋯ The output can be presented graphically as Box-whisker plots. A tutorial is included in the package.
-
In order to disclose differences between users and non-users of oral contraceptives (OC), 620 women aged 15-54 were invited to participate in an in depth interview about sexual, contraceptive, and reproductive life events. Of the 585 women who participated, 459 were consecutive gynecological in- or outpatients, and 126 were selected from visitors in general practice. Data was analysed by multivariate test statistics. ⋯ No correlation was found to coital frequency (whether earlier, present or during pregnancy or menstruation), number of births and abortions, or to social classification. In epidemiological research on benefits and risks of oral contraceptives, confounding influence of one or more variables is of crucial importance. The present findings point at sexual and life-style habits as potential confounders in the study of OC and associated diseases.