Vital rates of India for intercensal period with declining fertility and declining mortality.
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Asia↗
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Results for “Fertility Decline”
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Fertility decline in aging roosters is related to increased testicular and plasma levels of estradiol.
The relationships between testicular and plasma hormone levels and the decline in fertility in aging roosters were examined. Body mass, testicular mass, and fertility were measured in roosters from 20 to 72 weeks of age. Plasma was assayed for LH and testosterone, and estradiol and testicular extracts were assayed for testosterone and estradiol contents. Fertility increased rapidly in young roosters to a peak of 96.2 +/- 3.9% at 37 weeks of age. Thereafter, fertility declined and by 72 weeks of age was significantly lower than at 37 weeks. Plasma LH reached 16.8 +/- 2.5 ng/ml at 27 weeks and remained high until 60 weeks of age, when it decreased significantly. Plasma and testicular testosterone levels increased from low levels in young birds to a peak that coincided with highest fertility and declined thereafter. Plasma and testicular estradiol showed a striking inverse relationship with testosterone. Plasma estradiol was 29.4 +/- 4.0 pg/ml in 20-week-old birds, decreased rapidly as testosterone increased, and increased again in older birds as testosterone decreased. Thus, the decline in fertility in aging roosters was associated with a decrease in plasma LH and testosterone and an increase in plasma and testicular estradiol. It is suggested that plasma levels of LH and testosterone in roosters are regulated by a negative feedback mechanism involving estradiol that is produced not only by the aromatization of testosterone in the brain but also by peripheral estradiol originating in the testes and that estradiol has a major role in the decline in fertility in aging roosters.
Aging↗
Differentials in the rate of fertility decline: 1960-1970.
The continuous decline in fertility in the United States since 1957, while affecting all elements of the population, has been most pronounced and most rapid among those groups which previously had the highest fertility - blacks, American Indians and Mexican Americans-all of whom experienced fertility declines more rapid than those experienced by urban whites between 1957-1960 and 1967-1970. Among urban whites, fertility decline has been heavily concentrated among those of low income. The decline was especiallyrapid for third and higher order births, suggesting a heavy concentration of completed fertility at two-child families. The rapid decline, and the narrowing of the traditionalfertility differentials among various subgroups have important implications in the areasof poverty, education, the role of women in society and the dynamics of local area growth.
Black or African American↗
Late fertility decline in the Netherlands: the influence of religious denomination, socio-economic group and region.
The factors affecting the modern decline in fertility in the Netherlands are explored using data from censuses from 1930 to 1971 and additional unpublished sources. Particular attention is paid to the influence of religion, socioeconomic status, and region. The author concludes that "a theory formulated by Lesthaeghe and Wilson on the relation between modes of production and secularization and the pace of fertility decline in Western Europe offers--in combination with van Heek's views on the special position of Dutch Roman Catholicism--a starting point for an explanation of why the fertility decline of Roman Catholics, self-employed and agricultural labourers lagged behind." (summary in FRE)
Agriculture↗
Fertility decline in Bangladesh: toward an understanding of major causes.
Bangladesh has undergone a considerable decline in fertility, despite the absence of conditions believed to be necessary for such reproductive changes. Indeed, Bangladesh is the only one among the world's twenty poorest countries where such a change has occurred. The paper examines the nature of fertility transition in Bangladesh, looks at the trends in contraceptive use and fertility, and identifies the major factors accounting for the fertility decline, despite poor socio-economic conditions. Two types of factors in the decline are: (a) positive factors which encourage eligible couples to contracept, and (b) negative factors which compel women to contracept, for spacing or limiting births. The effects of positive and negative factors on contraceptive use and fertility are analysed with data from a rural sample of 4,194 women from the 1993-94 Bangladesh Demographic and Health Survey (BDHS), 2,597 women from the MCH-FP Extension Project area, and 8,110 women from the Matlab MCH-FP Project area. Logistic regression is used in the analysis. Strong and highly significant effects of female education, female employment and access to media on contraceptive use and fertility have been found.
Adult↗
[Overlying cultural factors: the saturation of tensions as an explanation of fertility decline in Switzerland].
"The purpose of this article is to provide an explanation of the recent decline of fertility in Switzerland with a saturation model. This process, which can be observed in the majority of highly developed countries since about 1965, is part of a long-term process of limitation of births." Factors considered in the model include the segregation between the work place and household, the development of social security systems, excessive consumption, and changing values. The model attempts to show that individuals are experiencing increasing structural and cultural tensions due to an increase in the impact of such factors that lead them to react in a variety of ways, some of which can affect the number and timing of births. The author suggests that both the fertility level and fertility decline have different determinants and concludes that fears of the "dying out" of the Swiss population are premature. (SUMMARY IN ENG AND FRE)
Behavior↗
Addressing Japan's fertility decline: influences of unintended pregnancy on child rearing.
Japan has been experiencing a continuing decline in fertility and an increase in premarital conceptions and abortions among young people. Child rearing is often viewed as a burden. In response, Japan is now seeking ways to improve the child-rearing environment for parents. In this context, we conducted a prospective study among 206 pregnant women in Sukagawa City, Fukushima, to explore the influences of pregnancy intention on child rearing. We found that unintended pregnancy was associated with a higher risk of negative child-rearing outcomes, including lower mother-to-child attachment, increased negative feelings of mothers and a lower level of participation of fathers in child rearing. Unintended pregnancy exacerbates the real and perceived burdens of child rearing. Japan is currently facing a conflict between wanting to reduce unintended pregnancies and increase the national fertility rate. We believe the government needs to address the social challenges affecting people's family lives, which underpin low fertility, rather than focus on fertility decline per se. We suggest Japan seeks to reduce unintended pregnancies and provide support to parents at high risk of child-rearing difficulties. We also suggest adopting a comprehensive approach to improving the lives of young couples, with a focus on adolescents, including life-skills education to prepare for adulthood, marriage and parenthood.
Abortion, Induced↗
Fertility decline and gender bias in northern India.
Although it is widely acknowledged that the preference for sons is a barrier to a decline in fertility, considerable disagreement exists as to what actually happens to this preference when fertility declines in a region of low female autonomy. By analyzing the data from the National Family Health Survey (NFHS), we present evidence from northern India to show that the preference for sons is reduced when the ideal family size becomes small, even though it does not completely disappear. This finding appears to contradict trends in the juvenile sex ratio and the incidence of female feticide that suggest the intensification of gender bias. We argue that the anomaly is the result of a diffusion of prenatal sex-diagnostic techniques in regions where there is a large unmet demand for such methods. Using the NFHS data, we estimate that in northern India, girls currently constitute about 60% of the unwanted births and that the elimination of unwanted fertility has the potential to raise the sex ratio at birth to 130 boys per 100 girls.
Birth Rate↗
The story of a 'maverick': Bulgaria's fertility decline.
Analysis of the fertility decline in Bulgaria shows that the perception of Bulgaria as an 'anomaly' in terms of its demographic development is based on a conservative interpretatiion of the demographic transition theory. The features that distinguish Bulgaria from the western European countries (faster decline, persistence of early and universal marriages, etc.) are generally accounted for by the specific social, economic, cultural, and political conditions. These findings suggest that the speed of the fertility decline and the means through which it is achieved are affected by a complex interaction between cultural and economic factors that are often difficult to distinguish in terms of primacy.
Bulgaria↗
Research progress on multi-mechanism analysis and protection strategies of ovarian aging and fertility decline.
Age-related fertility decline is an increasingly important challenge in reproductive medicine, driven largely by progressive ovarian aging. The aging ovary undergoes functional deterioration characterized by reduced ovarian reserve and declining oocyte quality, ultimately limiting female reproductive lifespan. Although multiple molecular and cellular processes associated with ovarian aging have been identified, these mechanisms are often discussed independently, limiting an integrated understanding of how they interact within the ovary. In this review, we propose an ovary-centered, multi-mechanistic framework to organize current evidence on ovarian aging and fertility decline. We discuss how genomic instability, telomere attrition, mitochondrial dysfunction, oxidative stress, chronic cellular stress responses, and alterations in ovarian signaling and microenvironmental homeostasis collectively contribute to follicle depletion and impaired oocyte competence. Particular emphasis is placed on signaling pathways involved in follicle activation and stress adaptation, including PI3K/AKT/mTOR, FOXO3, Hippo, and AMPK-Sirtuin networks, while acknowledging that many mechanistic relationships remain incompletely defined in physiological ovarian aging. Building on this integrative perspective, we further evaluate mechanism-oriented intervention strategies, including mitigation of cellular stress, metabolic and signaling modulation, optimization of the ovarian microenvironment, established fertility preservation technologies, and emerging exploratory approaches. By integrating current mechanistic and translational evidence, this review provides a conceptual framework for understanding ovarian aging and highlights future directions for evidence-based fertility preservation and reproductive health management in the context of aging.
Humans↗
Demographic and health status risk factors in childbearing among Indian women. Evidence from hospital data for the later stages of fertility decline.
Indirect estimates of maternal mortality in India indicate that fertility decline has reduced maternal deaths by reducing the frequency of pregnancy and childbirth. The earlier stages of fertility decline are also likely to have lowered maternal mortality by reducing the risk of pregnancy and childbirth as the proportion of births among risky multiparous, older women declines. However, further fertility decline may well be associated with some increase in risk. Risk will also remain high if the health status of Indian girls and women remains poor. This study uses a sample of maternal deaths and deliveries among patients who survived which occurred in Civil Hospital, Ahmedabad, Gujarat during 1982-1993 to investigate these issues further. The women in the sample have relatively low fertility and represent a fairly late stage of fertility decline. They also have persistently poor health status. Logit regression analysis reveals that although fertility decline is associated with some increase in risk, poor health status is the more important maternal mortality risk factor. Without attention to female health, even childbearing among expectant mothers with low fertility continues to be hazardous.
Adult↗
Women's lives in transition: a qualitative analysis of the fertility decline in Bangladesh.
The fertility decline that began in Bangladesh in the late 1980s and continues has prompted diverse theories to explain it. In this qualitative analysis of 21 focus-group sessions with rural women ranging in age from the teens to late 40s and living in the villages of the Matlab area, the women's perceptions of their changing society and of the influence of the family planning program are examined. The women's statements reveal their awareness of the social and economic transition they are undergoing and their interest in family-size limitation, which is bolstered by a strong family planning program. Although the shifts in economic and social circumstances are not large, in conjunction with the strong family planning program they constitute a powerful force for change in attitudes, ideas, and behavior among these women.
Adolescent↗
Men's influence on the onset and progress of fertility decline in Ghana, 1988-98.
While lower fertility is commonly associated with women's reproductive autonomy, we demonstrate that the influence of men's education on reproductive decision-making increased during the first decade of rapid fertility decline in Ghana. Husband's education exerts a stronger influence on wife's fertility intentions than does her own education, and the magnitude of the effect of his education increased significantly from 1988 to 1998. Lower fertility in Ghana seems to be associated more with men's declining fertility desires than with women's increasing reproductive autonomy. Nevertheless, there is some indication that women's education may play a relatively greater role in reproductive decision-making as fertility decline progresses still further.
Adult↗
Evidence for the involvement of epidermal growth factor in fertility decline in aging female mice.
A decline in fertility, defined as the number of implantation sites, was observed in mice as they aged; the decline started at 30 weeks of age and reached a nadir by 60 weeks when no implantation was detected. Epidermal growth factor (EGF) levels in the submandibular gland and plasma increased as the female mice aged, and sialoadenectomy (surgical removal of the submandibular glands) attenuated the rise in the plasma EGF level without affecting the overall health or survival of the animals. Uterine weight at 10-20 weeks of age was about 70 mg, and it significantly increased with age. This weight has increased more than 2-fold by 60 weeks. These changes closely followed the increase in the concentrations of EGF in the submandibular gland and the plasma. After sialoadenectomy, uterine weight decreased immediately and remained at about 50-60 mg throughout the experimental period. Interestingly, sialoadenectomized mice became pregnant at an older age than the controls. These findings suggest that elevated levels of EGF may have a physiological role in fertility decline in aging mice perhaps via uterine hypertrophy.
Aging↗
Fertility decline in Punjab, India: parallels with historical Europe.
Two interesting features emerge from this study of fertility behaviour in Punjab. First, it brings out the common features of peasant life and demographic behaviour found in this developing-country setting and in historical Europe. As in much of Europe, marriage was regulated to adjust to the availability of land and other resources. It is interesting to note that the operation of this 'nuptiality valve' was quite consistent with a system of joint families and partible inheritance. Secondly, the findings suggest that we need to re-define what we understand to be the features of socio-economic development which are crucial for fertility decline. Fertility began to decline steadily in this part of Punjab as early as 1940, at a time when the society was overwhelmingly agrarian, illiterate, and infant mortality was high with no access to modern contraceptive technology, as in historical Europe. The onset of the decline was brought about by development interventions which stabilized fluctuations in crop yields and mortality, thus radically improving stability of people's expectations. This study also points out the inapplicability of Mamdani's theories of fertility behaviour to the people he studies.
Europe↗
Fertility decline in East Asia.
With the fall of fertility in China to near or below replacement levels in the early 1990s, the whole of East Asia may now be said to have completed a demographic transition. Its experience lies between that of the West and the many developing countries in which demographic transition is now under way. The main features and possible underlying causes of the fertility declines in Japan, Taiwan, South Korea, and China during this century are discussed. Fertility decline in East Asia is interesting both in its own right, as a chapter in the history of human reproduction, and for the light it may shed on fertility decline in the rest of the world.
China↗
Analysis of the contradiction between the declining fertility rate and the rising birth rate in Anhui Province.
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Age Factors↗