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1.
Despite concern over high pregnancy rates and levels of risk for sexually transmittedinfections, adolescent fertility rates in the Dominican Republic have not changed substantially since the early 1980's, and actually increased during the early to mid 1990s. The present study was undertaken to assess the factors contributing to the recent rise in fertility among Dominican adolescents. The findings suggest that although contraceptive use among adolescents and young adults has increased, this has been more than offset by ominous trends on other determinants of fertility. Among these are declines in mean age at first sex and first marriage/union without a commensurate decline in mean age at first contraceptive use, and stubbornly high discontinuation rates for oral contraceptives andcondoms. There is also some evidence that rates of induced abortion among adolescents may have increased, without which adolescent fertility rates would have been even higher. Demand for children among Dominican adolescents remains strong, suggesting that efforts to reduce the current high prevalence of risky sexual behaviors need to influence social norms in order to be successful.  相似文献   

2.
Multiple decrement life table technique is used to analyze the oral contraceptive use in a sample of once married women in Metropolitan Toronto. The overall pattern in the Canadian data is found to be essentially similar to that found in the U. S. Continuation rates show differences by cause of decrement. Two types of rates, net and absolute, are presented, and the relationship between single decrement continuation rates and total continuation rates is examined. Some problems of clinical versus retrospective sample survey data in studies of contraceptive effectiveness are commented on.  相似文献   

3.
In this paper results recently published in this journal concerning the influence of birthspacing on child survival are reviewed, and two reasons are suggested why the statistical associations observed in the data collected in the World Fertility Survey may be, at least in part, spurious. Where reporting is poor, it is argued that errors may often be responsible for a substantial portion of the association between interval length and mortality, and also for the apparent influence of the death of one child on the survival prospects of a younger sibling. Where the reported dates of birth and death are reliable but contraceptive prevalence is high, there is the problem that contraceptive practice is apt to be closely associated with other behaviour likely to have a direct effect on mortality.  相似文献   

4.
The current status of and prospects for contraceptive methods is reviewed. Regulations governing the development, safety, and effectiveness of contraceptive methods are discussed, as well as the nature of the female and male reproductive system. Methods reviewed include coitus interruptus, the condom, spermicidal contraceptive agents, postcoital douching, the vaginal diaphragm, male and female sterilization, the rhythm method, oral contraceptives, IUDs, induced abortion, progesterone-releasing IUDs, postcoital estrogens, abortifacient agents (prostaglandins), immunization against human chorionic gonadotropin (HCG), pharmacologic suppression of the corpus luteum, long-acting injections of Depo-Provera, implantation of capsules containing norgestrel, the intravaginal ring, intracervical devices, release of contraceptive steroids through an arm bracelet, and male contraceptive agents. New areas of contraceptive research include influencing the release of luteininzing hormone-releasing hormone, 'turning-off' corpus luteum function in early pregnancy by competitors for HCG, affecting sperm or ovarian membranes to prevent fertilization, and interferring with sperm and egg development.  相似文献   

5.
Previous studies report that neighborhood characteristics influence pregnancy and childbearing risk among African-American adolescent women. These studies, however, leave unidentified the effects of many neighborhood properties on the proximate determinants of nonmarital fertility. In this study I examine the effects of neighborhood characteristics on the risk of nonmarital first intercourse and on contraceptive use among black female adolescents. The results suggest that neighborhood socioeconomic status, female employment and marital dissolution rates, and peers’ departure from mainstream lifecourse trajectories influence young black women’s sexual and contraceptive behavior. The effects of female employment and socioeconomic status are greater for teens in urban neighborhoods than for teens living elsewhere.  相似文献   

6.
In the developing world about 120 million women have an unmet need for contraception. They want to postpone childbearing, yet they do not use contraception, often because of the unavailability of services and supplies. However, according to a recent article by John Bongaarts, the primary factors are lack of knowledge about a contraceptive method, concern about side effects, and the disapproval of the male partner in developing countries. Lack of knowledge means inability to describe the uses of a contraceptive, its side effects, and the locale of its availability. An approximate knowledge index was calculated for such women, which showed that knowledge level positively correlated with contraceptive prevalence. Countries where the index was below 50% had a contraceptive prevalence of 8% only. The determinant reasons why women were reluctant to use the pill, IUD, and sterilization had to do with health and the fear of side effects, such as nausea and increased bleeding. The contraceptive prevalence among these women was reduced by 71% for the pill, 86% for the IUD, and 52% for sterilization. In Sub-Saharan countries nearly 70% of women cited partner disapproval of contraception, although they had never discussed family planning with their partners. The central concept for reducing unmet need is access with quality, which means that services are voluntary, safe, and appropriate in delivery. Some of the recommendations to reduce the unmet need for contraception include: one-on-one same-sex discussions to increase contraceptive knowledge and acceptability; sensitive responses by programs to their client's health concerns; support by service providers to women negotiating with male partners in order to mitigate male disapproval; and sex education and family planning services to reduce unwanted and early sexual contact and pregnancy while girls develop identities apart from mothering roles.  相似文献   

7.
Accurate measurement of induced abortion is necessary for understanding the fertility dynamics of a population and for making projections about the future. Changes in abortion rates can amplify or dampen the impact of changes in contraception. This paper presents a methodology for calculating marital induced abortion rates from observed marital fertility and contraceptive prevalence and for modeling the impact of substituting contraception for abortion on future fertility. The methodology is validated against observed abortion complications in three populations, and the impact of substituting contraception for abortion on expected fertility is demonstrated.  相似文献   

8.
Literature on the effect of decision-making patterns on contraceptive use often does not (1) distinguish between women participating in decisions and controlling them, and (2) account for effects of common decision-making patterns within the community. In Uganda where high fertility persists, both of these factors may be relevant to adoption of contraception. We used data from the 1995/96 Negotiating Reproductive Outcomes (NRO) Study which surveyed 1,750 women in 78 communities located in two districts in Uganda. We assessed the effects of individual and community factors on the adoption of modern contraceptive methods using multilevel logistic regression. We included measures of decision-making patterns at both the individual and community levels that distinguished husband-dominated, joint, and wife-dominated decision-making patterns. Contraceptive use is 29% more likely in communities where women more commonly have unilateral control over household decisions. This strong effect of normative decision-making patterns within the community is net of individual education and community education, both of which had strong and significant effects. Less traditional gender roles as measured by normative decision-making patterns seem to support more innovative fertility behavior. Community decision-making patterns matter importantly for contraceptive use in this low contraceptive prevalence setting and need to be assessed elsewhere. Further, women’s influence is inadequately measured where joint decision-making and wife-dominated decision-making are considered together.  相似文献   

9.
Education and family planning can both be influenced by policy and are thought to accelerate fertility decline. However, questions remain about the nature of these effects. Does the effect of education operate through increasing educational attainment of women or educational enrollment of children? At which educational level is the effect strongest? Does the effect of family planning operate through increasing contraceptive prevalence or reducing unmet need? Is education or family planning more important? We assessed the quantitative impact of education and family planning in high-fertility settings using a regression framework inspired by Granger causality. We found that women's attainment of lower secondary education is key to accelerating fertility decline and found an accelerating effect of contraceptive prevalence for modern methods. We found the impact of contraceptive prevalence to be substantially larger than that of education. These accelerating effects hold in sub-Saharan Africa, but with smaller effect sizes there than elsewhere.  相似文献   

10.
In this paper the hypothesis that ‘contraceptive confidence’ promotes accelerated childbearing is presented and examined. Methodological difficulties in investigating the question empirically are discussed. Because of the absence of a direct measure, a proxy indicator of ‘contraceptive confidence’ is used in multivariate analyses of maternity history data. These give results consistent with the existence of a contraceptive confidence effect. Evidence is also presented (a) of shorter second birth intervals among women who were in higher status occupations before marriage and (b) of an inverse association between educational qualifications and length of intervals after the first. These findings are construed as supporting the basic thesis regarding contraceptive confidence. The contraceptive confidence idea is discussed in the context of related work on an acceleration effect associated with women's labour-force participation. Several difficulties in interpreting the findings are considered and some implications are discussed.  相似文献   

11.
The prevalence of intentional control of reproduction increases in developing countries in which there is rapid modernization, and there are also important changes in breastfeeding practices. The effects of increased contraception and reduced breastfeeding on the pace and level of fertility and on the patterns and levels of infant and early childhood mortality are in opposite directions. In this paper we propose a technique to estimate the net effects of such changes on the natural rate of increase, and to assess the gross contribution of the various components of change. Applications of the technique to Latin American countries indicate that changes in fertility due to higher contraceptive prevalence are dominant, but that they are partially offset by the indirect effects on fertility of changes in breastfeeding. Likewise, changes in breastfeeding have the strongest direct impact on infant mortality, but are partially offset by the beneficial effects of a more favourable pace of childbearing induced by higher contraceptive prevalence.  相似文献   

12.
Much of the inconsistency that has appeared in studies of the effect of women's work on fertility in less developed countries has been attributed to the varying accessibility of employment in the modern sector. The analysis presented in this paper shows that continuity of work matters more than sector of work. It also confirms that, even in a setting of low contraceptive prevalence, increased fecundity associated with the less intense breastfeeding practices of working women do not result in shorter birth intervals. The influence of women's work on fertility control is likely to be underestimated if the effects of sporadic versus continuous work are conflated, or if fecundity differentials by work status are unmeasured.  相似文献   

13.
Much of the inconsistency that has appeared in studies of the effect of women's work on fertility in less developed countries has been attributed to the varying accessibility of employment in the modern sector. The analysis presented in this paper shows that continuity of work matters more than sector of work. It also confirms that, even in a setting of low contraceptive prevalence, increased fecundity associated with the less intense breastfeeding practices of working women do not result in shorter birth intervals. The influence of women's work on fertility control is likely to be underestimated if the effects of sporadic versus continuous work are conflated, or if fecundity differentials by work status are unmeasured.  相似文献   

14.
Potter RG 《Demography》1966,3(2):297-304
Two problems are associated with the analysis of use-effectiveness of contraception. First, couples belonging to a sample of contraceptors typically vary in their monthly chances of contraceptive failure. Second, one does not observe for many, and perhaps a majority of the couples, how long they can remain protected with the contraceptive, because either they are stopping contraception to plan a pregnancy or else observation of them is being interrrupted by lost contact, by discontinuation of contraception for other reasons, or by the end of the study. It is argued that because of these two problems-namely, sample heterogeneity and incomplete histories-the Pearl pregnancy rate, which has been traditionally used to measure contraceptive effectiveness, is inadequate.A life table method is described that permits one to combine incomplete histories with complete ones for purposes of estimating the proportions of the sample that might have remained protected for specified periods if all members had remained under observation for these periods. The versatility of the techniques is illustrated in relation toa retrospective survey. A detailed account of procedure is given. Finally, it is shown that only under specialized conditions that are rarely met in practice is it possible to estimate the results of the new technique from knowledge of Pearl pregnancy rates alone.  相似文献   

15.
Redundant use of contraception occurs when periods of contraceptive use overlap with periods of reduced fecundity, and will downwardly bias estimates of contraceptive failure rates. This paper investigates this bias using calendar data from the Demographic and Health Surveys. The paper presents unadjusted and adjusted 12-month failure rates for each of nine countries. The impact of redundant use on failure rates is generally modest. It tends to be greater in Indonesia, however, where both the incidence and the duration of overlap are relatively large.  相似文献   

16.
This paper examines the influence of media messages about family planning, and attitudes toward media promotion of family planning, on contraceptive behavior of married women in Ghana. It also examines the problem of reverse causation that arises in studies of this nature when the data used provide no information on the temporal order of the actual time that respondents were exposed to family planning information in the mass media and the time of adoption of contraceptive behavior. The results show that exposure to media messages on contraception exerts strong impact on current practice of, and intention to use, contraception. Women who had heard or seen advert on contraceptive brands, and women who favor broadcast of family planning messages in the media, are significantly more likely to adopt birth control behavior than women who had not heard or seen, and women who do not favor broadcast of such media messages, respectively. Regarding the problem of reverse causation, the study demonstrates that while being exposed to media messages significantly affects a woman's contraceptive behavior, the reverse does not seem to be the case. The policy implications of these results and how mass media could be used to promote family planning in Ghana are discussed.  相似文献   

17.
The use of contraceptives varies widely among Asian countries. Based on the most recent survey data available, the rate varies from nearly 8/10 married women aged 15-44 in Taiwan to fewer than 1/10 in Pakistan and Nepal. Women in East Asian countries are most likely to practice contraception, followed by those in Southeast Asia, with lower contraceptive prevalence rates found in South Asia. The rates of some East Asian nations now match those of the US and other developed nations, while in most South Asian nations contraception is spreading slowly. Contraceptive methods in use vary widely by country. The leading method in the greatest number of countries is sterilization, but in most countries several methods are nearly equal in popularity. Only in India is sterilization used by a majority of those people who practice contraception. Japan is the only country in which a majority of contraceptors use condoms, and only in China do 1/2 use IUDs. The choice of a particular contraceptive method is strongly influenced by 1) methods available through family planning programs, or promoted through the use of target systems; 2) religous and cultural factors; 3) concerns about side effects and safety; 4) ease of access to particular methods; 5) the medical profession; and 6) legality--in Japan the pill is illegal. In most countries the type of contraceptive that people prefer has changed since the introduction and promotion of modern methods of contraception. In general, there has been a shift to more effective methods. An increase in female sterilization at the expense of other methods such as the IUD or pill is the most common pattern. In countries where female sterilization is unpopular, use of such modern methods as the pill, IUD, or condom has increased at the expense of traditional methods.  相似文献   

18.
Abstract A probability model, building on the work of Perrin and Sheps, is presented and applied. The model makes it possible to follow a cohort of women from a pregnancy outcome to next conception. Principal simplifying assumptions are homogeneity among women and constant fecundity. Cases treated include no contraception; a single contraceptive method practised; and a second contraceptive method practised following a first one. Expected durations to next conception may be calculated in relation to the following factors: outcome of previous pregnancy, length of anovulation, natural fecundability, time first contraceptive method is initiated, characteristics of first contraceptive (effectiveness and continuation rate), characteristics of second contraceptive, and gap between termination of first and commencing second contraceptive. By suitably pairing runs of the model, one can construct experiments in which the only differentiating factor is use and non-use of a specified contraceptive, and, by differencing the corresponding mean durations to next conception, compute the net delay of next conception produced by that contraceptive.  相似文献   

19.
Lewis GL 《Population index》1983,49(2):189-198
The United States Agency for International Development (USAID) selected Westinghouse Health Systems to carry out contraceptive surveys. The primary objectives of the Contraceptive Prevalence Surveys (CPS) are to determine periodically the levels of contraceptive use in the country; to examine the correlates of and differentials in these levels in order to assess the impact of various types of governmental and nongovernmental programs; to identify factors that will facilitate an increase in contraceptive use, particularly factors involved in program planning activities; and to institutionalize in each country the capability to design and implement studies of contraceptive prevalence, to be undertaken at regular intervals by an in-country agency. Each CPS generally collects data on the basic demographic background of the country concerned, knowledge of contraceptive methods, prior contraceptive experience and current method used, past fertility behavior and future fertility intentions, present utilization of various types of service delivery systems, perceived accessibility of contraceptives, and reasons for nonacceptance of contraception. In the CPS project, data collection and field operations have been strongly stressed. Efforts have recently been made to expand the extent and sophistication of CPS data analysis. For example, 2 countries are currently using a series of mathematical techniques called synthetic estimators to estimate subnational levels of contraceptive use by merging CPS and census data. Westinghouse, in cooperation with the University of Michigan, is currently working to develop community characteristics module for inclusion in future CPS projects.  相似文献   

20.
Abstract The calculation of the number of births prevented for each item of contraceptive service provided entails the integration of a variety of factors relating to the potential fertility of users and the duration and effectiveness of use. This article differs from previous essays of this kind in that estimates of future potential fertility are based not on fertility rates but on age-specific means of inter-live birth intervals, modified by periods of use overlapping post-partum sterility, and by the probabilities attached to the development of permanent sterility and to the successful adoption of extra-programme birth control. In the first three years after acceptance of intra-uterine contraception by some 9,000 postpartum women of several ethnic origins in Singapore, it is calculated that about 4,800 births were prevented.  相似文献   

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