Showing papers on "Fertility published in 1968"
Journal Article•
127 citations
Journal Article•
TL;DR: Clinical observations indicate a high percentage of women conceive promptly after discontinuance of oral contraceptives, and longer use of the IUD decreased conception rates.
Abstract: This statistical evaluation of human fertility following the discontinuance of intrauterine contraception uses as its main source of data the Cooperative Statistical Program. On January 1 1968 files contained 746 reported women who had IUDs removed because the couple wanted a child. Of these 611 were followed for at least 3 months after removal. 527 or 86% were known to have conceived. Younger women conceived at higher rates than older ones. Longer use of the IUD decreased conception rates. Fertility rates following discontinuation of oral contraceptives is less available and reported statistics are thought to be inadequate. Clinical observations indicate a high percentage of women conceive promptly after discontinuance of oral contraceptives.
125 citations
TL;DR: The inhibitory actions of α-ergocryptin on fertility and lactation in the rat are altered differentially in the 2-bromo derivative of this ergot alcaloid, and it is unlikely that the fertility inhibiting and the lactation inhibiting effects of 2- bromo-α-ergOCryptin are governed by a single mechanism of action.
Abstract: The inhibitory actions of α-ergocryptin on fertility and lactation in the rat are altered differentially in the 2-bromo derivative of this ergot alcaloid. It is therefore unlikely that the fertility inhibiting and the lactation inhibiting effects of 2-bromo-α-ergocryptin are governed by a single mechanism of action.
124 citations
TL;DR: Family history data derived from the records of three parishes in Bavaria provide evidence for several important demographic questions when analysed in conjunction with information concerning the prevalent breast-feeding practices, and suggests strongly that breast feeding can prolong birth intervals substantially.
Abstract: Family history data derived from the records of three parishes in Bavaria provide evidence for several important demographic questions when analysed in conjunction with information concerning the prevalent breast-feeding practices. The results suggest strongly that breast feeding can prolong birth intervals substantially. The evidence concerning the independent influence of infant deaths on subsequent birth intervals is inconclusive. It is clear, however, that even if such an influence did exist it was relatively small, compared to the effect of lactation. In addition the results do not lend support to the hypothesis that couples experiencing low child mortality practised family limitation more than couples experiencing high child mortality. In all three parishes, however, fertility appeared to influence infant mortality. Infants born after short intervals were subject to considerably higher mortality risks than infants following longer intervals.
92 citations
Journal Article•
62 citations
57 citations
54 citations
TL;DR: In this article, the authors used survey data collected in predominantly lower-and middle-income neighborhoods of San Juan, Puerto Rico, to test three propositions: participation in the labor force is associated with increased influence by the wife in family decision-making, particularly with respect to having additional children.
Abstract: Using survey data collected in predominantly lowerand middle-income neighborhoods of San Juan, Puerto Rico, the author tests three propositions. (1) Participation in the labor force is associated with increased influence by the wife in family decision-making, particularly with respect to having additional children. (2) This increased influence in decision-making is associated with lower fertility among working women. (3) The negative relationship between laborforce status and fertility is stronger among wife-dominant and egalitarian families than among husband-dominant couples. Empirical support is present for each proposition.
50 citations
Journal Article•
44 citations
TL;DR: The findings suggest that circulating sperm-agglutinating antibody may be just a reflection of the immunologic process involved rather than the cause for the state of infertility.
TL;DR: The author points out that employment per se is not associated with lower fertility, rather white collar employment is strongly associated with later marriages and lower fertility and barriers against the employment of women in white collar and professional jobs should be undermined by governments.
Abstract: Data collected in 1966 among middle- and lower-class Puerto Rican women is used in an attempt to assess the effect of role incompatibility on the relationship between fertility and the employment of wives. The specific hypothesis tested is: "the greater the incompatibility between the roles of mother and worker the greater the differential fertility behavior of workers and women not in the labor force." 4 measures of relative role incompatibility are used: occupation child-care patterns attitude toward mothers working away from home and any combination of these. White collar and professional jobs which require training and continuity on the job are regarded as creating role incompatibility. Leaving ones children in the care of relatives does not create the incompatibility that hiring an outsider for child care does. The data generally supported the hypothesis. However a more complete analysis would have involved other factors as well such as the attitude of the husband toward the wifes employment the proportionate contribution of the wifes income to the total family income maternity leave policies and the cost availability and perceived adequacy of child care. To those who look forward the employment of women as a means of reducing the fertility level the author points out that employment per se is not associated with lower fertility. Rather white collar employment is strongly associated with later marriages and lower fertility and barriers against the employment of women in white collar and professional jobs should be undermined by governments. On the other hand establishment of day care facilities might tend to raise fertility since child care would no longer be a major obstacle to the working mother.
TL;DR: There is a significant difference between urban and rural-small urban fertility as measured by average number of live births, and it can be said that fertility tends to be higher for consensually marrieds in cities with a higher proportion of common law marriages.
Abstract: Preliminary results of recent surveys on fertility in rural and small urban areas in Latin America are compared with the results of previous surveys which concentrated on large Latin American cities. The large urban areas are Buenos Aires Mexico City Rio de Janeiro Bogota Caracas Panama and San Jose Costa Rica. The rural-small urban areas are Cauquenes-Chanco and Mostazal Chile; Cartagena and Neira Colombia; and Guelavia-Teotitlan and Pabellon Mexico. Although there are large differences in fertility among urban areas and to a lesser extent among rural-small urban areas there is a significant difference between urban and rural-small urban fertility as measured by average number of live births. No definite conclusions can be drawn between nuptial patterns and fertility levels. At best it can be said that fertility tends to be higher for consensually marrieds in cities with a higher proportion of common law marriages. There is a clearcut difference between the education level of urban and rural-small urban women and this shows up in fertility levels with illiterates having the highest fertility. The largest difference occurs at the completed primary level; differences for secondary and higher levels are much less marked and in some cities there is even a slight upturn at the university level. In urban areas fertility tends to decrease as the occupational status of the husband increases. In rural-small urban areas agricultural workers particularly lower level ones tend to have more children. In the cities there is a trend toward higher fertility among nonworking women; in the rural-small urban areas no clearcut differences in fertility exist perhaps because work in these areas is often done in the home and strongly linked to traditional modes of life. In the urban areas there is a much greater incidence of contraceptive use and to some extent this runs parallel with lower fertility. However the data does not distinguish between the effectiveness of different methods or the regularity with which they are used. The use of contraception increases with educational level.
01 Jun 1968
TL;DR: In this article, Assortative mating by educational attainment in relation to fertility is discussed. But the authors do not discuss the relationship between educational attainment and fertility in terms of fertility.
Abstract: (1968). Assortative mating by educational attainment in relation to fertility. Eugenics Quarterly: Vol. 15, No. 2, pp. 98-112.
01 Sep 1968
TL;DR: In this article, a follow-up study of a male Kalamazoo public school population showed that fertility was positively associated with occupational status, IQ, educational attainment, and size of family of origin.
Abstract: (1968). Relation of fertility to occupational status, IQ, educational attainment, and size of family of origin: A follow‐up study of a male Kalamazoo public school population. Eugenics Quarterly: Vol. 15, No. 3, pp. 198-203.
TL;DR: This article examined the hypothesis that a high rate of participation of women in the labor force tends to reduce birth rates in a community and found that women's work participation was negatively associated with various measures of fertility.
Abstract: This report examines the hypothesis that a high rate of participation of women in the labor force tends to reduce birth rates in a community. Among metropolitan areas in eight countries about 1950 the proportion of women working was negatively correlated with the child-woman ratio. This relationship held even when the percentage of women married was controlled by partial correlation. Among metropolitan areas of the United States in 1960, women's work participation was negatively associated with various measures of fertility. This was true for eight categories of women grouped by color and age. Further, communities wit?' high levels of female employment tended to have both low proportions of married women and low marital fertility. On the whole, the correlations for nonwhites were lower than those for whites and fell into a somewhat different pattern. The evidence examined is consistent with the hypothesis, but the nature of the causal connection between work participation and fertility is not directly demonstrated.
TL;DR: In this article, the authors examine the second category of fertility differentials, namely urban-rural differentials between the settled agricultural populations and the pastoral nomads, and the fertility among the latter being apparently unusually low.
Abstract: Statistically valid records of birth and death registration do not yet exist in the Sudan. The I955/56 sample census gave some evidence though not very conclusive' that there were fertility differentials in the country. These differentials were of three main types. First, there were differentials between the inhabitants of the three Southern provinces where recorded fertility levels were exceptionally indeed suspiciously high; and the Northern provinces where recorded fertility levels were considerably lower. Second, within the Northern populations, there appeared to be fertility differentials between the settled agricultural populations on the one hand, and the pastoral nomads on the other, fertility among the latter being apparently unusually low. Third, there was some evidence of urban-rural differentials. Of these three types of fertility differentials, the second is possibly the most important, since the avowed policy of the Sudan Government is directed towards the settlement of the nomadic part of the population. Indeed, even in the absence of an explicit policy of settlement, any extension of irrigation schemes and thus of the area of cultivable land2 will automatically result in the settlement of formerly nomadic or partially nomadic peoples. This settlement was dearly reflected in the data obtained from the 1955/56 census, which revealed substantial movements of formerly nomadic peoples into the expanding agricultural areas.3 If such settlement results in a pronounced rise in the birth rate, the demographic repercussions of this movement should not go unforeseen. The object of this study is therefore to examine this second category of fertility differentials. Do these differentials in fact exist, and if so, what are the causes ? The answer to these questions was the principal purpose of a demographic sample survey conducted in I96I /624. In this paper, however, attention will be confined to the first of these questions the establishment of the
TL;DR: Fertility in young adults with cystic fibrosis is a major concern and an interesting and challenging area for future research.
Abstract: IN recent years as the life-span of patients with cystic fibrosis has increased, new problems have arisen. The latest is fertility in young adults with this disease, about which an interesting and ...
Book•
01 Jan 1968
TL;DR: Society and population, Society and population, مرکز فناوری اطلاعات as discussed by the authors, سعلاط رسانی
Abstract: Society and population , Society and population , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی
TL;DR: The Hirado Health Survey, to be described shortly, was an effort to combine an ad hoc census with routinely collected vital and demographic observations; it was directed, broadly stated, toward the ascertainment of (1) the fertility of the consanguineous marriage, (2) the reproductive performance of the inbred individual, and (3) certain observations on the children born to parents, especially mothers, who are themselves the products of consanguinous marriages.
Abstract: Until recently, it has been commonplace both to deplore the lack of realism in most, if not all, genetic models used in the study of human populations and to acknowledge that few data existed from which improvements might stem. Interest and energy have, however, begun to focus upon the collection of data which hopefully will serve as bases for the formulation of more insightful and presumably more realistic models. Some investigators have, for example, turned to routinely collected vital and demographic data on the supposition that these observations, if pertinent, would be especially useful because of their numbers, breadth, and depth in time. Thus far, for a variety of reasons, the results have not lived up to expectations. Other investigators have tended to emphasize ad hoc censuses. They argue that demographic units are unfortunately more apt to be defined by geographic, political, or socioeconomic considerations than biologic ones, and though this bias can be offset to some degree in specific instances by judicious selection of the units to be studied, an ad hoc census of some variety may still be necessary if the routine data are to be fully plumbed. The Hirado Health Survey, to be described shortly, was an effort to combine an ad hoc census with routinely collected vital and demographic observations; it was directed, broadly stated, toward the ascertainment of (1) the fertility of the consanguineous marriage, (2) the reproductive performance of the inbred individual, and (3) certain observations on the children born to parents, especially mothers, who are themselves the products of consanguineous marriages. The study itself represents a conscious attempt to incorporate into traditional demographic and census procedures a few readily measurable genetic parameters. Inbreeding is, in Japan, such a parameter, and its relationship to fertility and fecundity may be one of the main avenues through which we can discern and measure the contribution of genetic factors to reproduction. Numerous considerations, administrative and scientific, entered into the choice of Hirado and the design and implementation of the survey. To mount the kind of demographic study implicit in the objectives just enumerated requires a population of a size sufficient to demonstrate differences in fertility among consanguinity classes, if differences exist, and yet not so large that the population would be inordinately difficult to study. Clearly, the population must be inbreeding at a rate such that a census of persons and households would reveal a substantial number of inbred individuals and consanguineous marriages. Ideally, the population would be sharply delimited geographically, and as static as possible. 1\\oreover, it would seem advantageous in view of the effect of socioeconomic factors upon fertility to select a population as homogeneous in this regard as possible. Finally, if the census observations were to supplement routinely collected data, as proposed, the population to be censused had to correspond to some Japanese administrative unit upon which vital and demo-
TL;DR: The article ends with a discussion of the hazards of "borrowing from the future" that is overestimating avoided births and error inherent in the optimism of family planning administrators.
Abstract: Methods of computing numbers of births averted by family planning programs are described and the important factors enumerated; in some cases mathematical formulae are shown. The simplest method is to estimate the trend in births in the total population before and after instituting the program and attribute the excess decrease in births to the program. This approach attributes positive catalytic effects and negative effects (such as better health) on birth rates to the program. The second method is to compare expected and actual births among contraceptors in the program area taking into account marital age and specific fertility. It may include bias from higher fecundity of acceptors which may be removed by ignoring the last birth or using fertility rates of the last 3 or 5 years. The third method is to compare matched study and control groups or matched pairs. The fourth method is to compare the number of couple-years (or months) of effective contraception. The estimate as used for the IUD program in Taiwan took into account pregnancy-expulsion-removal rate mortality-sterility rate accidental pregnancy and postpartum amenorrhea. Significant distortions appeared from substitutions of the IUD by other effective methods especially in women over 30. It was concluded that this computation to be valid required follow-up data on length of usage and pregnancy rate and KAP data on selective fertility of acceptors. The article ends with a discussion of the hazards of "borrowing from the future" that is overestimating avoided births and error inherent in the optimism of family planning administrators.
TL;DR: It is argued that the indicators of unusually low fertility in the highland, predominantly Indianspeaking areas fail to control effectively for the very high levels of infant mortality in these regions.
Abstract: Using the census data for Peru, Bolivia and Ecuador, previous writers have investigated some possible determinants of inter-regional differences in fertility; language spoken, female participation ...
TL;DR: The National Fertility Study as mentioned in this paper found that the proportion of Catholic wives using contraceptive methods other than rhythm increased since 1955 and became a majority by 1965 and that this type of nonconforming is related strongly and inversely to such measures of religiousness as frequency of receiving communion and less directly to measures of socioeconomic status and ethnic background.
Abstract: The data reported were derived from the National Fertility Study a probability sample of 5600 US wives surveyed in late 1965. The proportion of Catholic wives using contraceptive methods other than rhythm increased since 1955 and became a majority by 1965. This type of nonconforming is related strongly and inversely to such measures of religiousness as frequency of receiving communion and less directly to measures of socioeconomic status and ethnic background. There is an especially pervasive tendency for contraceptive nonconformity to be related to age at marriage independently of other measured variables. A comparison of data by birth cohort and age for comparable studies in 1955 1960 and 1965 reveals a systematic reduction and at progressively earlier ages in the proportion of Catholic women conforming to their Church Magisteriums position on birth control. The trend prevails for all socioeconomic subdivisions and degree of religiousness. Between 1955-60 those with less education showed the greater increase in use of methods other than rhythm; between 1960-65 those with more education showed the greater increase. This reversal may be associated with the advent of oral contraception and the publicity about the theological debates within the Catholic Church. (authors modified)
TL;DR: In this article, the sequence of births occurring in a closed female population subject to constant schedules of fertility and mortality can be represented as where only one coefficient (Q0) and one exponent (r0) are real.
Abstract: The sequence of births occurring in a closed female population subject to constant schedules of fertility and mortality can be represented as where only one coefficient (Q0) and one exponent (r0) are real. Convergence to a stable population occurs a few years after all complex components in B(t) have become negligible relative to the one real component. The rate of convergence of B(t) to a real exponential function depends on the age schedules of fertility and mortality, and on the initial age distribution. Methods of determining the coefficients and exponents of the terms of B(t) by use of a large computer are described in this paper, and various significant characteristics of the terms are given. Methods are described for visualizing how convergence would occur in a particular human population on the basis of recorded features of its fertility, mortality, and age composition.