Fertility Trends Research Articles

Indicators of the Social Dimension of Demographic Development (on the Example of the Republic of Mari El)

This paper analyzes social dimensions of demographic policy, which include the size, composition, and changes in indicators of natural population development. Against increasing life expectancy, comparative monitoring of the demographic indicators of the Russian Federation, the Volga Federal District, and the Republic of Mari El revealed negative trends in fertility, mortality, and natural population decline. To clarify the measures of demographic policy, the authors carried out a sociological survey of the youth of Yoshkar-Ola, who answered questions about the causes and factors affecting the dynamics of the demographic situation.

Chinese trends in adolescent marriage and fertility between 1990 and 2015: a systematic synthesis of national and subnational population data

Early marriage and fertility are major social determinants of health and wellbeing. Rapid shifts in the past three decades, including a rise in sexual activity in unmarried adolescents, a large population of young migrant workers, and a high proportion of males relative to females, have the potential to alter patterns of reproductive health in Chinese adolescents and young women. We aimed to establish long-term trends of marriage and fertility for girls and women aged 15-24 years in China. We did a longitudinal study in which we extracted aggregated data for marriage and childbearing status for Chinese girls and women aged 15-24 years from the Chinese National Population Census (in 1990, 2000, and 2010) and the Chinese 1% National Population Sample Survey (in 1995, 2005, and 2015). The census included all individuals with Chinese nationality who resided in China when the survey was done. For the 1% sample survey, communities or villages were randomly selected and all residents with Chinese nationality in the selected communities or villages were included. In all censuses and sample surveys, forms that included information on basic demographic characteristics, education, marriage, and fertility were completed and verified by the census enumerators at the household residence, based on responses provided by the householder or another adult in the household. We calculated the ever-married rate and age-specific fertility rate (ASFR) for all included individuals. We built multivariate random-effects generalised least squares regression models on panel data to test whether marriage or fertility rate was associated with education level, sex ratio, and the proportion of the population who are an ethnic minority in a province. The ever-married rate for those aged 15-19 years decreased from 4·7% in 1990 to 1·2% (95% CI 1·2-1·3) in 2000, but rebounded to 2·4% (2·4-2·5) in 2015. The ASFR for this age group decreased from 22·0 births per 1000 individuals in 1990 to 6·0 (5·9-6·0) births per 1000 in 2000, and rebounded to 9·2 (8·9-9·4) births per 1000 in 2015. The rebound was found in most provinces. In women aged 20-24 years, the ever-married rate generally declined from 58·6% in 1990 to 25·5% (95% CI 25·4-25·6) in 2015, and the ASFR decreased from 198·8 births per 1000 in 1990 to 55·0 (54·5-55·5) births per 1000 in 2015. In 2015, the ever-married rate and ASFR for girls and women in rural areas aged 15-19 years were three-times higher than those of their urban counterparts (3·8% [95% CI 3·7-3·9] vs 1·1% [1·1-1·1] for the ever-married rate and 15·4 [14·9-15·9] vs 4·1 [3·9-4·3] births per 1000 for the ASFR). There were large disparities in ever-married rate across individuals of different education levels, with increases in the ever-married rate of 15-19-year-olds not attending senior high school between 2000 and 2010. Those aged 15-19 years were more likely to be married or give birth in the western provinces. Education held a protective association against adolescent childbearing, whereas a high ratio of males to females and a high proportion of ethnic minorities were associated with greater risk. Although China's total fertility rate remains far less than replacement, after a period of steady decline, there has been a rebound in adolescent marriage and childbearing in the past decade. A range of adolescent-targeted strategies will be needed across provinces, including scaling up comprehensive sex education, ensuring that girls continue in school, and providing adequate reproductive health services, which specifically meet the needs for modern contraception in sexually active unmarried girls. Humanities and Social Sciences Planning Fund Project, Sports and Health Special Project of Education and Scientific Research, and China Scholarship Council.

U.S. Fertility Decline and Recuperation Following the Great Recession by County-Level Industrial Composition of the Labor Force

Amid a persistent U.S. fertility decline since the Great Recession, fertility recuperation patterns by geographic regions were not homogeneous. This study hypothesizes that the geographic discrepancies in fertility patterns are attributable to different labor force compositions by the regions. We use data from the U.S. Census Bureau’s Annual Estimates of the Resident Population County Components of Population Change to estimate the discrepancy in fertility variations at the county-level. By comparing the slopes of births before and following the recession, we visualize the characteristics of fertility variations at the U.S. county-level. Also, a multiple linear regression model estimates that the counties with a greater share of labor force in wholesale trade, information & technology, finance & insurance, and professional & scientific industry show greater volatility in fertility trends throughout the Great Recession. On the contrary, the counties with higher proportions of the labor force in agriculture, retail trade, and education industry tend to less change over the years of the economic recession. However, fertility recuperation is limitedly identified amid the structural fertility decline after the Great Recession.

Live Births and Fertility Amid the Zika Epidemic in Brazil.

In late 2015, the Brazilian Ministry of Health and the Pan American Health Organization classified the increase in congenital malformations associated with the Zika virus (ZIKV) as a public health emergency. The risk of ZIKV-related congenital syndrome poses a threat to reproductive outcomes that could result in declining numbers of live births and potentially fertility. Using monthly microdata on live births from the Brazilian Information System on Live Births (SINASC), this study examines live births and fertility trends amid the ZIKV epidemic in Brazil. Findings suggest a decline in live births that is stratified across educational and geographic lines, beginning approximately nine months after the link between ZIKV and microcephaly was publicly announced. Although declines in total fertility rates were small, fertility trends estimated by age and maternal education suggest important differences in how Zika might have impacted Brazil's fertility structure. Further findings confirm the significant declines in live births in mid-2016 even when characteristics of the municipality are controlled for; these results highlight important nuances in the timing and magnitude of the decline. Combined, our findings illustrate the value of understanding how the risk of a health threat directed at fetuses has led to declines in live births and fertility.

Saving for the future: Evaluating the sustainability and design of Pension Reserve Funds

In several countries public finances are under pressure by pension obligations rising due to downward trends in fertility, increased longevity and financial markets with low interest rates. For these reasons, the establishment of Pension Reserve Funds (PRF) has flourished. Regardless of the specific objectives that these PRFs may have, a critical issue is to assess their sustainability over the long-run. Moreover, this sustainability analysis is particularly complex, due to the interaction between the macroeconomic environment, financial performance and the labor market.In this article, we use a projection model aimed to evaluate the sustainability of the PRF in a small open economy such as Chile. The case of Chile is interesting because it shares common features with economies open to international markets that have either defined benefits pension schemes and/or defined contribution schemes with minimum pension guarantees. Moreover, since the Chilean PRF features relatively well defined contribution and withdrawal rules, we have a framework against which our methodology can be used to explore the effects on PRF's sustainability of altering these rules.Our methodology takes into consideration the stochastic nature of macroeconomic, financial and labor market variables in order to evaluate the sustainability of the PRF. In contrast to deterministic measures such as funding ratios, our methodology is more appropriate to assess the role of the contribution and withdrawal rules for PRFs in evaluating the key underlying risks and their consequences for the sustainability of PRFs.

Visualizing fertility trends for 45 countries using composite lattice plots

Background: The Human Fertility Database (HFD) and Human Fertility Collection (HFC) provide disaggregated data on age-specific fertility rates for 45 countries. These sources offer the opportunity to learn about the development of different pathways of transition to low fertility both within and between countries. Objective: The aim of this paper is to use composite fertility lattice plots, which combine information from different visualization techniques of the Lexis surface, namely level plots and contour plots, to explore changes in age-specific fertility rates (ASFRs) and the implied (period-based) cumulative cohort fertility rates (cumulative pseudo cohort fertility rates, CPCFRs) across countries and geographic regions. Methods: Through key examples we introduce a new refinement of the Lexis surface, combining level plots, which use colour/shade to indicate ASFRs, and contour lines to indicate fertility milestones for given cohorts (CPCFRs). We have also developed a web-based app to allow researchers to produce their own fertility Lexis surfaces. Results: Results show that once countries have fallen below a replacement fertility level, they tend to not return to it. Exceptions are Norway and the United States, which saw rising fertility rates for cohorts born after the 1950s and late 1960s respectively. The age-specific fertility trends, as well as broader political and socioeconomic conditions, are very different in these countries, suggesting different paths by which replacement fertility rates might be achieved. Contribution: Complex data visualizations show, in an intuitive way, how ASFRs are related to successive cohorts’ fertility milestones (CPCFRs). Combining this information enables us to explore differences between countries and can make an important contribution to comparative fertility research.

Fertility trends of women with serious mental illness in the United Kingdom 1992–2017: A primary care cohort study using the clinical practice research datalink

BackgroundChanges in care may mean women with serious mental illness (SMI) are more fertile. We investigated 1) the live-birth and pregnancy rate of women with and without SMI over time, 2) the likelihood of pregnancy when using second or first-generation antipsychotics. MethodRetrospective cohort study of women (15–45 years) registered in Clinical Practice Research Datalink (CPRD) general practices between 1992 and 2017. Each analysis year, women with SMI (affective and non-affective psychotic disorder) were matched with up to four women with no record of SMI on age, calendar year and general practice. Pregnancy and live-birth rates and the rate ratio (RR) comparing women with and without SMI were estimated. The stability of the RR between years was tested. For women with SMI, the pregnancy rates when on or off first or second-generation antipsychotics were calculated and compared using Poisson regression models. ResultsIn total, 12,524 women with SMI were matched to 50,074 women without SMI, median age 34 [IQR 28–39] years. Between 1992 and 2017 women with SMI had 50% fewer live-births than women without SMI (RR 0..50, 95%CI 0.45–0.55). The pregnancy rate ratio increased from 0.64 (95%CI 0.48–0.86) (1992–1994) to 1.00 (95%CI 0.81–1.22) (2016–2017), (p < 0.0001), but this change was only seen in women with affective disorders. Women are most likely to become pregnant after discontinuing either a second-generation or first-generation antipsychotic (RR 1.74, 95%CI 1.42–2.13). ConclusionsWomen with SMI are increasingly experiencing pregnancy but not live-birth, which suggests the reproductive health needs of these women are unmet.

Warren C.Sanderson and SergeiScherbovProspective Longevity: A New Vision of Population AgingCambridge, MA: Harvard University Press, 2019. 264 p. $45.00.

The “new vision” of elderliness promoted by Sanderson and Scherbov replaces a simple age marker, typically 65 years, by a measure of future life expectancy, say 15 years. They call the prospective old-age threshold as the chronological age corresponding to this future life expectancy. For the US population as of 2018, this threshold age (for a 15-year future life duration) is 71.5 years. In Japan it is 74 years; in Nigeria it is 58 years. In many countries, over the middle decades of last century, the proportions of the population 65 and above and the proportions with 15 years or below of prospective life were roughly the same; with rising longevity, the first of these proportions increases dramatically, the second at only a modest pace. Under projected trends in mortality and fertility, the divergence between the two proportions will continue to grow over the next few decades. Similar divergences were found between standard and prospective measures of population aging for other indices, such as old-age dependency ratios. In effect, the new vision takes a lot of the drama out of the aging process. Sanderson and Scherbov have described and elaborated this approach in numerous articles over the last 15 years, several of them in this journal. The present book pulls the work together and aims to make it accessible and persuasive to a wider audience. Success will be measured by the extent of adoption of the prospective aging indices and, more important, of the underlying conceptual shift they represent. (Some resistance to thinking prospectively about aging may be encountered—seen, for example, in the widespread protests against President Macron's efforts to reform France's pension system, hoping to raise retirement ages above 62.) The book's material gets fairly technical in places, notably in a chapter on the “characteristics approach” to population aging (earlier treated in PDR 39, no. 4). The text is leavened by discursions on the history of old-age dependency definitions and anecdotes such as on record times for 100 m sprints in the 105- to 110-year-old age group. Later chapters look afresh at such questions as: Is the quality of life in old age getting worse? Will population aging ever stop?

Predicting parity progression ratios for young women by the end of their childbearing life

Abstract Parity progression ratios (PPR’s) have been extensively described in literature on demography and have played an important role in fertility, unlike the idea of calculating projected parity progression ratios proposed by Brass (1985). However, we decided to use this method in our paper to analyse future fertility trends, firstly by assessing age-specific parity progression ratios for women in childbearing ages, and then by comparing these ratios with ratios at the end of women’s reproductive life, as well as by comparing the latter with the completed PPR’s. More specifically, the aim of this study is to adopt a modified Brass method to calculate the projected parity progression ratios using the age-period fertility data sourced from the Human Fertility Database (HFD). We progress to use the observed and predicted age-specific PPR’s to examine parity progressions in Poland as a case study.

Ultra-low Fertility and Policy Response in South Korea: Lessons from the Case of Japan

South Korea’s fertility rate declined rapidly beginning in the late 1970s. By 2005, it had fallen to an all-time low of 1.08 per woman. This shift has contributed to a significant and continuing increase in the ratio of elderly to working-age population. In 2006 and 2010, the Korean government instituted policy plans intended to support child-rearing in the context of a modern industrialized society. However, increases in fertility rates during the years that followed were slight and inconsistent. In 2016, the government presented its Third Initiative for Low Fertility and Aging Society, but this program has been criticized, especially for focusing, like the earlier plans, too narrowly on financial subsidies rather than addressing culture and infrastructure as well. The present study examines these policy responses and compares them to the case of Japan, where a substantial reversal in the recent low fertility trend appears to have followed targeted, broad-based policies from both the central and regional governments, as well as voluntary programs by employers. The study recommends that Korea, like Japan, should not only engage multiple stakeholders but should broaden the scope of policy responses to account for the research-supported interrelationship among factors associated with education, culture, and economics.

The “Population Problem” in Pacific Asia

Reviewer: Gavin W. Jones, Australian National University Throughout East Asia, as well as in Singapore and Thailand, fertility rates have reached very low levels, and this has led to declining youth populations (throughout the region), followed by declining working-age populations (almost everywhere in the region), and declining total populations (already in Japan, soon to be followed by South Korea and Taiwan). The prospective population ageing in these countries by mid-century is extraordinary, though the measure of ageing used (ratio of the population aged 65+ to the “working age” population aged 15–64) provides an overly alarming picture of population ageing, given the rapid changes in the characteristics of Pacific Asia’s older population. In any event, these trends have led to considerable alarm on the part of governments, notwithstanding the arguments of many environmentalists that population decline is to be welcomed rather than feared. Stuart Gietel-Basten’s book traces out very effectively the trends in fertility and population size and structure in the Pacific Asian countries, offers an insightful analysis of the factors keeping fertility low, the policy concerns of their governments, and some approaches to enabling their population to realize their family building desires. His book raises many important issues, in some cases in innovative ways.

Integrated soil fertility and yield trend in response to long-term fertilisation under the Chinese double rice-cropping systems

Soil fertility is fundamental in determining crop productivity and sustainability in farming systems. A long-term fertiliser experiment in Chinese double rice-cropping systems initiated in 2011 was used in this study to gain an insight into a complete estimating of soil fertility. The six fertiliser treatments included mineral fertiliser (NP, NK, and NPK), combined NPK with farmyard manure (NPKM) or crop straw (NPKS), and no fertiliser application as a control. Results showed that grain yield averaged 5.5–13.0 t/ha/year, and significant increasing trends were observed in the phosphorus-applied plots (NP, NPK, NPKM, and NPKS), but the treatments without phosphorus applied (control and NK) resulted in declining trends in both early- and late-rice yields. After long-term rice cultivation, the contents of total and available phosphorus significantly declined in phosphorus-deficient plots compared to other treatments. Regression analysis showed that the improvement in grain yields was positively correlated with the increased soil fertility over treatments. Relative to the NPK treatment, the NPKM treatment greatly enhanced soil fertility from 0.50 to 0.78, and particularly dramatically increased the content of available soil phosphorus. Therefore, the high grain yield and soil fertility can be simultaneously achieved by long-term balanced fertiliser applications in Chinese double rice-cropping systems.

Pathways to Parenthood in Social and Family Context: Decade in Review, 2020.

This article reviews research from the past decade on patterns, trends, and differentials in the pathway to parenthood. Whether, and under what circumstances, people become parents has implications for individual identity, family relationships, the well-being of adults and children, and population growth and age structure. Understanding the factors that influence pathways to parenthood is central to the study of families and can inform policies aimed at changing childbearing behaviors. This review summarizes recent trends in fertility as well as research on the predictors and correlates of childbearing, with a focus on the United States and on research most relevant to family scholars. We document fertility differentials and prevailing explanations for variation across sub-groups and discuss alternative pathways to parenthood, such as adoption. The article suggests avenues for future research, outlines emerging theoretical developments, and concludes with a discussion of fertility policy. U.S. fertility has declined in recent years; whether fertility rates will increase is unclear. Elements of the broader social context such as the Great Recession and increasing economic inequality have impacted pathways to parenthood, and there is growing divergence in behaviors across social class. Scholars of childbearing have developed theories to better understand how childbearing is shaped by life course processes and social context. Future research on the pathways to parenthood should continue to study group differentials, refine measurement and theories, and better integrate men and couples. Childbearing research is relevant for social policy, but ideological factors impact the application of research to policy.

Decrease of Fertility without Increase in Contraceptive Use: Interrelationship between Migration and Fertility Behavior in Himali Gaunpalika in Nepal

Migration from Nepal to other countries over the last 200 years includes pilgrims, devotees, political refugees, and soldiers. Throughout the twentieth and 20 years of the twenty-first century, Nepal has increased its role as a major labour-exporting country and mostly economy depends on remittance. This research paper explores the new trends of fertility and tendencies of contraceptive are in relation to migration especially male, ecology and population dynamics. Use of contraceptive is not usually determined by the use of contraceptive in case of human in general but in some cases, fertility is a complex whole which can be determined by multiple factors like ecology, religion, culture, social dynamics, demographic dynamics etc. The objective of this paper was to identify the situation of migration trends in relation to fertility in the study area. Fertility mainly depends on male migration towards abroad and even in India, geography, climate (cold climate), heavy work load due to difficult geography, food habit (mainly carbohydrate sufficiency rather than protein based) etc. are playing a key role for decreasing fertility rather than using contraceptives in case of Himali Gaupalika of Bajura district of Nepal.

Research Trends and Prospects for Fertility

Research Trends and Prospects for Fertility

Recent trends in soil fertility across the farms of East Gippsland

Current data are needed to manage our soil resources but there are few recent purpose-built surveys of soil fertility, a critical asset for natural resources management. Instead, data collected for other purposes are re-used as has been the case in our area of interest here: managing the threat of soil erosion on farm land in East Gippsland. The dynamic nature of soil fertility challenges this approach, so we conducted a new survey using 234 paddocks selected at random. These new data were compared to re-purposed legacy data. Plant tissue samples from a selected subset were used to assess micronutrients. Separately, 27 paddocks that had been sampled during 1975–89 were re-tested to examine temporal changes. We concluded that many paddocks are now strongly or very strongly acidic and deficient in molybdenum (Mo) and boron (B). More specifically, those under dairying, cropping and horticulture are likely to have adequate phosphorus (P) while those grazed for meat and wool are likely to be deficient in P. We concluded that grazing enterprises need to either re-adopt soil testing and fertiliser treatment or adopt management practices suitable for acid soils deficient in P, Mo and B, if their paddocks are to support sustainable productive agriculture. Data from the re-tested paddocks suggest that, in general, many were once less acidic, highlighting the difficulties in using legacy data. Also, contrasts in soil pH and available P between paddocks under different management regimes, highlighted the difficulties in using re-purposed data. We concluded that a statistically designed survey is a preferable basis for natural resource management.

Fertility Level, Trend and Differentials in Nigeria: A Multivariate Analysis Approach

We present an empirical approach to changes in some fertility measures using multivariate profile analysis to determine level, trend and differences in fertility measures in Nigeria. ASFR, TFR and MNCEB was studied with respect to residency for three time points. Results obtained showed strong evidence of mean differences in TFR across zones with both ASFR, TFR and MNCEB showing no interaction with respect to residency. Various profile plots and tests showed evidences of parallelism for all the fertility measures considered. Some implications and suggestions with regards to policy formulation were also given.

Reproduction of Human Resources in Urban and Rural Areas of Russia: What the Number of Children Depends On

The urbanization processes in Russia have had a significant impact on the state of human resources in urban and rural areas, including the decline in the birth rate. As part of this study, the authors studied the characteristics of the births of the first and subsequent children in urban and rural areas, as well as the influence of such factors as the level of per capita incomes of the population. In the course of analysis based on averaged time data for the subjects of the Russian Federation from 2010 to 2017, a cross section was conducted. His results showed the presence of various, sometimes opposite fertility trends of the first and subsequent children among the population in urban and rural areas. So, the birth of the first child both in the city and in the village practically does not depend on the income level of the population. With respect to subsequent children, the opposite trend is observed—in the city, with the growth of income, the total birth rate of second and subsequent children decreases, while in rural areas it grows. According to the authors, these processes are influenced not only by objective factors—the proportion of women of reproductive age, but also subjective—by the features of reproductive behavior, including an increase in the age of birth of the first child in rural areas.

Reproductive efficiency and survival of Holstein-Friesian cows of divergent Economic Breeding Index, evaluated under seasonal calving pasture-based management

The objective of the current study was to examine phenotypic fertility performance and survival, and to gain insight into underlying factors that may contribute to greater fertility performance in 2 divergent genetic groups (GG) of Holstein-Friesian, selected using the Irish Economic Breeding Index (EBI). The GG were evaluated across 3 spring calving pasture-based feeding treatments (FT) over 4 yr. The 2 divergent GG were (1) high EBI; representative of the top 5% nationally (elite), and (2) EBI representative of the national average (NA). In each year, 90 elite and 45 NA cows were randomly allocated to 1 of 3 FT: control, lower grass allowance, and high concentrate. No interaction between GG and FT was observed for any of the measures of fertility investigated. The elite cows achieved significantly greater pregnancy rate to first service (+14.9 percentage points), and significantly greater pregnancy rates after 21, 42, and 84 d of breeding (+17.3, +15.2, and +9.6 percentage points, respectively) compared with NA. The number of services per cow was fewer for elite (1.57) compared with NA (1.80). The interval from mating start date to pregnancy was significantly shorter for elite cows compared with NA. The elite cows maintained greater mean body condition score than NA throughout the study (2.91 vs. 2.72), and had greater body condition score at calving, artificial insemination, and drying off compared with NA. The elite cows had greater mean circulating concentrations of insulin-like growth factor-1 compared with NA. No significant effect was observed of GG on commencement of luteal activity, or progesterone profile variables. Greater survival to the start of fifth lactation was observed for elite cows. The elite cows were 43% less likely to be culled than NA by the beginning of the fifth lactation. The results highlight the success of the Economic Breeding Index to deliver reproductive performance and longevity consistent with industry targets across a range of seasonal pasture-based FT. The results also clearly demonstrate the potential of appropriate genetic selection to reverse negative fertility trends incurred during previous decades of selection for milk production alone.

The fertility revolution in Zimbabwe with special regards to proximate determinants of fertility

The role of proximate determinants in moderating fertility decline is well documented in developing countries. In Zimbabwe, however, there is a limited understanding of the role of proximate determinants on fertility levels and trends. This study aimed to examine the role of proximate determinants of fertility (namely marriages, postpartum infecundity and contraception) using the Bongaarts proximate determinants model. The impact of these determinants is studied on a sample of married women aged 15–49 years’ and corresponding cross-sectional data obtained through the six consecutive Zimbabwe Demographic Health Surveys (ZDHSs) hold in 1988, 1994, 1999, 2005 and 2015. The results reveal that the overall fertility declined from 5.4, 3.8 and 4.0 children per woman observed among 1988, 1999 and 2015 ZDHSs, respectively. This change was caused by the contraceptive inhibitive effect, which correspondingly increased from 3.00 to 4.65 and 6.45 children per woman. The fertility stalling observed in 1999 and after that is caused by postpartum infecundity and marital fertility inhibition which decreased with time. Moreover, contraceptive inhibition effect increased with education, wealth quintiles, and urban residence. In contrast, marital and postpartum infecundity fertility inhibition effects inversely correlate with education, wealth quintiles, and the place of residence. Therefore, to foster further fertility decline to replacement level, policies should promote contraceptive adoption, more extended breastfeeding periods and delay entry into early marriages. Furthermore, women empowerment, especially the promotion of female education to higher education and female employment, could be useful tools to further fertility decline.