Fertility Decline Research Articles

Single-cell transcriptomic atlas of goat ovarian aging

BackgroundThe ovaries are one of the first organs that undergo degenerative changes earlier in the aging process, and ovarian aging is shown by a decrease in the number and quality of oocytes. However, little is known about the molecular mechanisms of female age-related fertility decline in different types of ovarian cells during aging, especially in goats. Therefore, the aim of this study was to reveal the mechanisms driving ovarian aging in goats at single-cell resolution.ResultsFor the first time, we surveyed the single-cell transcriptomic landscape of over 27,000 ovarian cells from newborn, young and aging goats, and identified nine ovarian cell types with distinct gene-expression signatures. Functional enrichment analysis showed that ovarian cell types were involved in their own unique biological processes, such as Wnt beta-catenin signalling was enriched in germ cells, whereas ovarian steroidogenesis was enriched in granulosa cells (GCs). Further analysis showed that ovarian aging was linked to GCs-specific changes in the antioxidant system, oxidative phosphorylation, and apoptosis. Subsequently, we identified a series of dynamic genes, such as AMH, CRABP2, THBS1 and TIMP1, which determined the fate of GCs. Additionally, FOXO1, SOX4, and HIF1A were identified as significant regulons that instructed the differentiation of GCs in a distinct manner during ovarian aging.ConclusionsThis study revealed a comprehensive aging-associated transcriptomic atlas characterizing the cell type-specific mechanisms during ovarian aging at the single-cell level and offers new diagnostic biomarkers and potential therapeutic targets for age-related goat ovarian diseases.

The continuing decline in cohort fertility and mixed evidence of narrowing educational differences

Background Typically, women with higher levels of education have had fewer children and were more likely to be childless compared to those with lower levels of education. However, in recent years, there has been a trend of fertility convergence between education levels in several high-income countries, including Australia. New data are needed to determine whether this trend has continued and fertility remains educationally stratified among Australian women.
 Aims Using the latest available data from the 2021 Australian Census, the aim of this study is to compare the average completed fertility and number of children ever born of women born between 1952 and 1981, with a specific focus on how these metrics vary by education level.
 Data and methods Data on the number of children ever born are sourced from the 2021 Australian Census to compute population statistics (completed cohort fertility, proportion of women by parity, and parity progression ratios) for six educational categories (postgraduate, graduate, bachelor, diploma, year 12, year 11 and below) and six cohort groups (1952-56, 1957-61, 1962-66, 1967-71, 1972-76, 1977-81). These statistics are used to describe trends in fertility patterns over time and by education.
 Results Completed cohort fertility has continued to decline slowly, from 2.22 for the1952-56 birth cohorts to 1.89 for the 1977-81 birth cohorts, mostly due to an increase in childlessness and a decrease in larger families with more than two children. There has been more divergence than convergence by education level, with those with bachelor's or diploma qualifications experiencing greater declines in fertility than any other education group. Although childlessness rates by education level have converged, women with lower education have also become increasingly likely to have larger families.
 Conclusions While there is evidence of convergence in childlessness rates across different levels of education, the gap in fertility rates between education groups continue to increase in Australia.

The Decline and Fall of Human Fertility

Over the last half century, the world has seen a steep decline in fertility in virtually every country on Earth, with the result that most advanced industrialized societies now have fertility rates that are well below replacement levels (conventionally set at 2.1 children per woman). This decline in fertility has been particularly marked in the Tiger economies of Southeast Asia but is essentially ubiquitous, even in populous nations such as India and China. These trends mean that, in the short term, advanced industrialized nations such as Australia can only prop up their ageing, flagging populations by encouraging record levels of immigration. Ultimately, however, we need to address this issue by addressing the causes of global fertility decline, not its consequences. This decline is being driven by increasing prosperity through the mediation of a range of social factors, the most powerful of which is the education of women and an accompanying shift in life’s purpose away from procreation. In addition, environmental and lifestyle factors are also having a profound impact on our fecundity, particularly in the male where increasing prosperity is associated with an exponential rise in the incidence of testicular cancer and a secular decline on semen quality and testosterone levels. On a different time scale, we should also recognize that the reduced fertility rates associated with the demographic transition are lessening selection pressure on high fecundity genotypes. The retention of poor reproductive genes within the human population is also being exacerbated by the increased uptake of assisted conception therapy. If we continue to rely on the latter to solve all of infertility’s woes, the growth of the ART industry may ultimately reach a scale where it serves to reduce human fertility still further, leading our species into an infertility trap.

A Deep Dive into Germany’s Fertility Decline, Societal Responses, and Implications for Sustainable Economic Futures

This research provides a nuanced exploration of the intricate dynamics surrounding fertility decline in Germany. By examining the interconnections among economic, cultural, and social factors influencing demographic trends, the study unveils the complexity of this phenomenon. Employing a comparative framework, international experiences are critically analyzed to extract valuable insights and lessons, enriching the understanding of effective policy responses. The research identifies Germany's unique challenges within its demographic landscape, offering targeted policy recommendations. These recommendations are tailored to foster immediate demographic stability and cultivate enduring, sustainable outcomes, addressing the complexities of fertility decline in the country.

Fertility Transition in China and its Causes

Abstract Demographic transition faced by modern economies, including China, are among the most important long-term socio-economic challenges. In 2022, China observed its population decline for the first time since the early 1960s. The low fertility rate was of critical importance. The unprecedented one-child policy is quite commonly indicated as the main reason for the low fertility rate. However, the departure from this restrictive policy and the actions introduced under the two-child policy implemented from 2016, and then the three-child policy from mid-2021, have not brought an improvement in fertility rates. The aim of the paper is to answer the following research questions: Should the decline and persistent low fertility rate in China be attributed solely or mainly to the unprecedented one-child policy, which was in force for over three decades? Fertility transition in China is the effect of several factors and depends largely on the studied period. In the 1970s and 1980s, the government’s family policy was a key determinant of the decline in fertility. However, contrary to the prevailing belief about the determining influence of the one-child policy, the first stage of the implementation of the birth control policy, the Wan, Xi, Shao program, had a greater impact. Since the 1990s, the low fertility rate has been mainly explained by the extraordinary socio-economic changes and rapidly increasing prosperity of the Chinese people. Since the beginning of the 21st century, cultural changes resulting mainly from the integration of the Chinese economy with the global system have been crucial. Cultural changes have affected reproductive behaviour, marriage patterns, marriage postponement, birth postponement, fertility, and family size in Chinese society, which is observed below-replacement fertility. China’s demographic future depends on the fertility trajectory. However, due to the size of the population, but also the position of the Chinese economy in the global economic system, Chinese demographic transition may also bring significant consequences for the global economy.

#391 : Oocyte Cryopreservation — A Five Year Follow Up Study on its Utilization and Outcome

Background & Aim: Oocyte cryopreservation is a boon for women undergoing Assisted reproductive technology (ART). Apart from cancer patients it is recently promoted as a mode of fertility insurance to overcome the age-related decline in fertility, endometriosis, primary ovarian insufficiency, etc. The objective of the study was to evaluate the clinical applications of oocyte freezing and its efficacy in terms of pregnancy outcome. Method: Retrospective observational study of all patients undergoing oocyte cryopreservation from 2016 to 2021 in Lilavati Hospital & Research Centre, Mumbai, India. Result: 221 patients undergoing oocyte cryopreservation were included. Oocyte cryopreservation was done for different indications like azoospermia (50.2%, most common), planned oocyte freezing (41.17%), fertility preservation (1.36%), endometriosis (0.45%), ejaculatory dysfunction (1.8%), husband with active hepatitis B infection (3.62%) and unavailability of husband on the day of egg retrieval (3.62%). A total of 1715 mature oocytes were frozen. 41.17% women were normo-responder, 38.91% were poor responder and 19.90% were hyper-responder. The oocytes of 59 patients (return rate-26.7%) have been thawed and 162 women (73.3%) remain in storage. Out of 508 oocytes frozen for these 59 patients utilizing their oocytes, around 474 oocytes were recovered post-warming (recovery rate 93.3%). A total of 59.3% patients created embryos with a partner, and 40.6% used donor sperm. The mean fertilization rate was 65.8% of surviving oocytes. Of 59 patients, 44 (74.5%) planned a fresh embryo transfer, out of which 20 patients tested positive for pregnancy (pregnancy rate 45.45%). Conclusion(s): We report the outcomes of patients opting for oocyte cryopreservation, which is useful for patient counselling. Limited evidence is available in terms of utilization rate, post warming survival of oocytes, fertilization and pregnancy rate. Further studies over long period of time with larger cohorts are needed.

A Study on the Influence of Economic Policy on Fertility Reduction and the Countermeasures Based on China and Foreign Policy

It has been confirmed that China's fertility rate has fallen below the fifth lowest globally and has fully entered the low fertility trap. There is an urgent need to increase the fertility rate. This paper mainly studies the causes of the gradual decline in fertility in China in recent years. It compares the subsidy measures taken by various countries to cope with the low fertility rate. It compares the living cost and economic policy system in China to analyze how China should raise the fertility rate. Through the analysis and summary of the literature, it is found that the reasons for the decrease in China's fertility rate year by year are that the explicit and implicit costs of birth and raising are too high, and the allocation of educational resources is unfair, resulting in low social identity and low happiness. With the gradual decrease of the fertility rate, the population structure changes, and the risk increases, making it difficult for the fertility rate to return to normal. Therefore, China should follow the Nordic countries' policies on parenting costs and social welfare, favor multi-child families, reduce parenting costs after childbirth, improve family happiness, and introduce economic support policies for child-rearing. At the same time, China should avoid the policy risk of "only giving money" and avoid the ineffective phenomenon of increasing welfare but declining fertility rates instead of rising.

Research on China's Fertility Decline and Economic Sustainable Development

China's social development has been influenced by a myriad of factors, including labor force dynamics, population aging, and economic growth. Notably, the gradual decrease in the birth rate has emerged as a critical concern, warranting in-depth analysis of its implications. This paper delves into the current state of China's birth rate, identifies the challenges associated with it, and explores its impact on the nation's comprehensive national strength. This paper conclude that the effect of the birth rate on the sustainability of China's economy. As the domestic consumer base dwindles, economic growth may face obstacles due to reduced domestic demand. Additionally, a higher dependency ratio, with fewer workers supporting a growing elderly population, could further strain public resources and social welfare systems. In light of these challenges, this abstract offers recommendations to address the declining birth rate and its impact on China's economic development.

Does Abortion Liberalisation Accelerate Fertility Decline? A Worldwide Time-Series Analysis

Since WWII, the two most important global trends in family planning have been fertility decline and abortion liberalisation. But are they related? Specifically: Does abortion liberalisation affect changes in fertility rates? The demographic literature has yet to answer this important question and instead offers two opposing predictions. Some studies argue that liberalisation of this medical procedure reduces fertility rates. By contrast, others note that such legal reforms may merely have an average, negligible effect on fertility levels. We adjudicate between the two approaches by conducting, in our view, the most comprehensive global, quantitative analysis of the relationship between those legal reforms and changing fertility rates. The analysis relies on two-way fixed models and three different indicators of abortion policy liberalism created by independent research teams to estimate the relationship between abortion liberalisation and total fertility changes. The data cover 185 independent states between 1970 and 2019. Fertility rates are significantly related to average public education levels and alternative contraceptive use. Using multiple model specifications, however, abortion reforms do not have a robust association with the outcome. Replication materials for this article can be found at https://figshare.com/s/5336a4422f47c8c39228.

The Consequences of Fertility Decline on Educational Attainment in China

The Consequences of Fertility Decline on Educational Attainment in China

Production of local resource-based soil improvement materials as a community empowerment model in Sindangkasih Village, South Konawe

Most of the residents in Sindangkasih Village earn their livelihoods through farming. The survey results indicate a decrease in the level of agricultural productivity in this village due to a lack of knowledge in agricultural management, leading to a continuous decline in soil fertility. Conversely, the village serves as a livestock center, producing cow dung waste, and houses a grain milling industry that generates rice husk waste, both of which have not been optimally utilized. The goal of this community service is to provide training and assistance to enhance the knowledge of farmer groups in producing soil improvement materials based on local resources. The methods employed in the service activities include counseling, demonstrations on creating soil improvement materials, and group discussions with the participation of 30 individuals. The results of the activity demonstrate an increase in the knowledge and skills of the Sindangkasih Village community in producing soil improvement materials, particularly organic fertilizer, to support agricultural production.

Adverse effects of exposure to petrol-generator exhaust fumes on the reproductive hormones, testis and spermatozoa in male dogs

There is evidence that sperm count has progressively declined in men over the recent decades. Exposure to air pollutants including petrol and diesel exhaust have been reported to impair male reproduction although there is little experimental evidence. This study investigated the effects of petrol-generator exhaust fumes (PGEF) on semen, sperm, gonadal structure and hormonal status in the dog. Sixteen adult male Basenji dogs were randomly assigned four to each of 4 groups as follows: an unexposed (Control) group and three groups exposed to graded levels of PGEF for 1, 2 or 3 h per day (hpd), respectively, for 90 days. Serum concentrations of testosterone (T), follicle stimulating hormone (FSH) and luteinizing hormone (LH) were measured on days 0 (baseline), 30, 60 and 90 of the study. At day 90, semen samples were collected for semen and sperm analysis. Testicular and epididymal tissues were subjected to gross, histopathological and histomorphometric evaluation. Graded exposure to PGEF resulted in increased serum concentration of T and decreased concentrations of FSH and LH, increased seminal plasma lipid peroxidation, seminiferous and epididymal tubular degeneration, germ cell depletion, lowered sperm concentration, decreased sperm motility and vitality, and increased sperm abnormal morphology. The close proximity between dogs and humans in exposed environments underscores the importance of these findings to human reproductive health and fertility. The findings suggest that with prolonged exposure, the impairment of reproductive functions will likely play significant roles in the decline in male fertility.

Responsibility, social aspirations, and contemporary low fertility: a case study of rural West Bengal, India

ABSTRACT West Bengal, a middle-ranking Indian state in terms of development indicators with more than two-thirds rural population, is on the verge of becoming a lowest low fertility zone. While the rural TFR (Total Fertility Rate) of West Bengal (1.6 births/woman) is on par with many developed countries (Norway, Germany, Netherlands, Belgium, etc.), its developmental stage is not—which poses a paradox. Using data from a primary survey of 405 mothers aged 15–35 years alongside focus group data of parents, the present study employs a society-specific approach to explain contemporary low fertility in rural West Bengal. We argue that the presence of high aspirations for children in an economically insecure setting initiates a distinctive sense of parental responsibility that generates a unique local socio-ecology of low fertility not previously observed in the context of rural fertility decline in India. Responsibility-laden aspirations toward children and reasoned-rational deliberations regarding fertility outcomes act as subliminal motives to have a small family, challenging common assumptions regarding the relationship between economic hardship, rurality, and fertility.

MOTIVATION OF RICE FARMERS IN USING PLANT GROWTH PROMOTING RHIZOBACTERIA AT SEKAYU DISTRICT, MUSI BANYUASIN REGENCY

One of the most common problems in agriculture today is the decline in soil fertility on agricultural land due to the excessive use of chemical fertilizers and pesticide residues and processing of land with agricultural machinery. This study was to determine the level of motivation for using PGPR in lowland rice cultivation, what factors influence the level of motivation, as well as developing a strategy for applying motivation using PGPR in lowland rice cultivation. This research was conducted from April to June in Sekayu District, Musi Banyuasin Regency. The method used is descriptive method and multiple linear regression. Respondents were taken as many as 97 people who were determined purposively (purposive sampling). The results show that the level of motivation is included in the high category. Factors that have a significant effect on farmer motivation are the age of the farmer, the role of extension workers, the availability of facilities and infrastructure, the availability of agricultural information. Based on the multiple linear regression analysis test, it was found that the most critical indicator of farmer motivation was the availability of facilities and infrastructure. From these results an agricultural extension strategy was providing counseling on making PGPR independently in farmer groups.

Epigallocatechin-3-gallate improves the quality of maternally aged oocytes.

The decline in female fertility as age advances is intricately linked to the diminished developmental potential of oocytes. Despite this challenge, the strategies available to enhance the quality of aged oocytes remain limited. Epigallocatechin-3-gallate (EGCG), characterised by its anti-inflammatory, antioxidant and tissue protective properties, holds promise as a candidate for improving the quality of maternally aged oocytes. In this study, we explored the precise impact and underlying mechanisms of EGCG on aged oocytes. EGCG exhibited the capacity to enhance the quality of aged oocytes both in vitro and in vivo. Specifically, the application of EGCG in vitro resulted in noteworthy improvements, including an increased rate of first polar body extrusion, enhanced mitochondrial function, refined spindle morphology and a reduction in oxidative stress. These beneficial effects were further validated by the improved fertility observed among aged mice. In addition, our findings propose that EGCG might augment the expression of Arf6. This augmentation, in turn, contributes to the assembly of spindle-associated F-actin, which can contribute to mitigate the aneuploidy induced by the disruption of spindle F-actin within aged oocytes. This work thus contributes not only to understanding the role of EGCG in bolstering oocyte health, but also underscores its potential as a therapeutic intervention to address fertility challenges associated with advanced age.

RETRACTED ARTICLE: Gender-specific determinants of overweight and obesity among older adults in India: evidence from a cross-sectional survey, 2017-18

BackgroundA major societal trend of the twenty-first century is the rapidly ageing population as a consequence of the decline in fertility and increase in life expectancy. Along with the rise in ageing population, the burden of obesity and related non-communicable diseases is also equally rising. In this study, we aimed to investigate the potential gender-specific determinants of overweight and obesity among older adults in India.Subjects and methodsThe present study used data from the Longitudinal Ageing Study in India (LASI) wave 1 (2017–18). A total sample of 25,952 older adults (≥ 60 years) was selected for the study. Descriptive statistics, bivariate chi-square test, and logistic regression estimation were applied to accomplish the study objectives. Body mass index (BMI) has been classified in this study according to the WHO criteria.ResultsThe prevalence of overweight was higher among women (18.15% in rural areas and 46.62% in urban areas) compared to men (12.9% in rural areas and 30.61% in urban areas). Similarly, obesity was higher among women than men who were residing in urban areas (17.07% vs. 5.37%), had secondary or above education (32.38% vs. 6.1%) belonged to richest strata (16.37% vs. 4.50%), or had mobility impairment (9.2% vs. 2.8%). Despite adjustment for several confounders, women were more likely to be overweight (OR: 2.18; CI: 1.86, 2.55) and obese (OR: 3.79; CI: 2.86, 5.03) than men. However, among both the elderly men and women, those who were highly educated were 2.29 times (OR: 2.29; CI: 1.80, 4.11) and 2.71 times (OR: 2.71; CI: 1.78, 4.11), respectively more likely to be overweight than their illiterate counterparts. Older adults living in urban areas were more likely to suffer from obesity compared to rural men (OR: 1.47; CI: 1.07, 2.02) and women (OR: 2.58; CI: 1.85, 3.60). Both men and women, who were highly educated were 2.64 times (OR: 2.64; CI: 1.71, 4.09) and 2.94 times (OR: 2.94; CI: 1.40, 6.20), respectively, more likely to be obese than their illiterate counterparts. Older men and women who were richest (OR: 1.60; CI: 1.19, 2.14 & OR: 2.12; CI: 1.63,2.76), or had mobility impairment (OR: 1.33; CI: 1.09,1.61 & OR: 1.72; CI: 1.42,2.08) were more likely to be overweight than their counterparts who were poorest or did not have any mobility limitation, respectively.ConclusionsThis study found increased vulnerability of overweight and obesity among older women than men irrespective of their socioeconomic, demographic, and health status. The present study suggests that introducing preventative measures such as campaigns to encourage physical activity, and community awareness may help reduce the high burden of overweight and obesity. Finally, the findings are important for better functioning of any public health programme and suitable intervention techniques to maintain a healthy body in order to lower the prevalence and risk factors of non-communicable diseases in later life.

Screening of rhizosphere nitrogen fixing, phosphorus and potassium solubilizing bacteria of Malus sieversii (Ldb.) Roem. and the effect on apple growth

Nitrogen, phosphorus and potassium inorganic fertilizers are commonly used when growing apples, but their excessive application has resulted in a decline in soil fertility and therefore an inability to maintain sustainable cultivation systems. It is possible to compensate for this with biofertilizers. Nitrogen-fixing, phosphorus solubilizing, and potassium solubilizing bacteria are biofertilizers with a broad range of possible uses. In this study, beneficial microorganisms were screened from the rhizosphere soil of the apple tree, Malus sieversii (Ldb.) Roem., which is rich in microbial diversity in natural environments. It was essential to investigate their effects on the growth of apple seedlings. Eight populations of organic phosphorus solubilizing bacteria (56), inorganic phosphorus solubilizing bacteria (13), nitrogen-fixing bacteria (22), and potassium solubilizing bacteria (24) were isolated from eight populations of Xinjiang wild apple rhizosphere in Ili by medium culture. Their morphological characteristics were recorded and their activity was determined. The most active strains were Pseudomonas migulae, Pseudomonas poae, and Pseudomonas extremaustralis, which was determined by physiological and biochemical properties and 16S rDNA sequence analysis. The L16 (45) orthogonal experiment, which used the three strains as testing materials, was created to assess the effects of the strains on apple physiological indicators, soil nutrients, leaf nutrients, and biomass, as well as to identify the ideal combination, concentration, timing, and application method. The results indicated that the peroxidase (POD) and catalase (CAT) activities of apple seedlings increased significantly under the 10 treatment, and the (SOD) activities of the 0 (control) and 1 (inorganic fertilizer only) treatments were significantly lower than the other treatments; soluble sugar, soluble protein and chlorophyll contents increased in all treatments compared to 0 and 1, while malondialdehyde and proline contents increased or decreased compared to 0 and 1; apple seedlings in treatment 10 had the highest soil N, P, and K content, leaf N, P, and K content and biomass were also all highest in treatment 10. In summary, the strains screened for the test can be used as biofertilizers and the optimum application was determined for treatment 10, meaning that the results also provide a theoretical basis for their application in artificially grown orchards.

Two crops are better than one for nutritional and economic outcomes of Zambian smallholder farms, but require more labour

Sustainable intensification practices suitable for smallholders in southern Africa will be needed to counteract the impact of future climate change and soil fertility decline in the region. Diversification of maize-based farming systems with grain legumes could play a key role. Here, we compared the performance of different maize-legume diversification strategies (single-row intercropping, strip cropping, and crop rotation) with sole cropped maize under conventional ploughing and Conservation Agriculture in four Zambian districts in the Eastern and Southern Provinces. These options were assessed using the Sustainable Intensification Assessment Framework (SIAF), with metrics representing productive, economic, human, social, and environmental dimensions. Data were collected from on-farm trials over three growing seasons. We found no significant effect of cropping systems on individual maize and legume grain yield across growing seasons, but substantial nutritional and economic benefits of intercropping systems due to simultaneously growing two crops. In particular, maize-legume intercropping strategies (single-row intercropping and strip cropping) resulted in higher energy and protein yield at cropping system level than sole maize and maize-legume rotation, which had positive implications for human nutrition. Although there were increased labour requirements to manage the intercrops, and particularly the strip crops, these cropping systems had much higher net benefits and returns to labour and inputs than the other cropping systems tested. Farmer evaluations however did not show a preference for the intercropping systems over the maize-legume rotation or sole maize, most likely because labour and its availability may be as or more important for farmers than overall cropping system benefits. Soil organic carbon content and soil pH did not differ between the tested cropping systems at the start of the trials and after three cropping seasons, but decreased over this period independently of the cropping system. Overall, the results indicate that maize-legume strip cropping, and single-row intercropping can increase food and nutrition security as well as gross benefits from farming, but this comes at the expense of greater labour requirements throughout the growing season. The latter may be addressed through, e.g., appropriate-scale farm mechanization, if intercropping or strip cropping systems are to become a viable option for labour, not land, constrained farms in Southern Africa.

DNA methylation profiles in bovine sperm are associated with daughter fertility

ABSTRACT The current decline in dairy cattle fertility has resulted in significant financial losses for dairy farmers. In the past, most efforts to improve dairy cattle fertility have been focused on either management or genetics, while epigenetics have received less attention. In this study, 12 bulls were selected from a provided 100 bull list and studied (High daughter fertility = 6, Low daughter fertility = 6) for Enzymatic methylation sequencing in the Illumina HiSeq platform according to the Canadian daughter fertility index (DFI), sires with high and low daughter fertility have average DFI of 92 and 112.6, respectively. And the bull list provided shows a mean DFI of 103.4. 252 CpGs with methylation differences greater than 20% (q < 0.01) were identified, as well as the top 10 promising DMRs with a 15% methylation difference (q < 1.1e−26). Interestingly, the DMCs and DMRs were found to be distributed more on the X chromosome than on the autosome, and they were covered by gene clusters linked to germ cell formation and development. In conclusion, these findings could enhance our ability to make informed decisions when deciding on superior bulls and advance our understanding of paternal epigenetic inheritance.

Is Pakistan’s fertility transition stalling?

ABSTRACT This study examines the question as to whether Pakistan’s fertility transition is stalling. The paper reviews the trajectories of fertility and its various determinants and compares Pakistan’s trends with those of India and Bangladesh. Countries in the South Asia region share features such as cultural similarities (e.g. the low status of women and son preference) and high poverty levels. However, while Bangladesh and India are near replacement fertility today with modern contraceptive prevalence rates well above 50 per cent, Pakistan still has one of the highest fertility and lowest contraceptive prevalence levels in Asia. Our main conclusion is that Pakistan’s fertility transition is close to stalling in mid-transition. The key causes of this stall are a high and unchanging desired family size, stalling demand for contraception and relatively low satisfaction of this demand. These are important obstacles to future decline in fertility.