Fertility

About: Fertility is a research topic. Over the lifetime, 29988 publications have been published within this topic receiving 681106 citations.

The proximate determinants of fertility in sub-Saharan Africa

Abstract: Rapid population growth has played an important role in producing the poor economic conditions that exist today in sub - Saharan Africa. However, in the past, few governments have expressed concern about demographic developments such as this. This is now changing and effective policies are being sought to reduce excessive fertility in order to effect a decline in the rate of population growth. The policy design and implementation of such policies would benefit from an understanding of the socioeconomic, cultural, biological and environmental factors that determine fertility. This paper seeks to provide such an understanding by assessing the proximate determinants of fertility. It is concluded that a rapid decline in fertility is unlikely to occur in the near future, partly because desired family size is very high and partly because upward pressure on fertility levels will result from the erosion of traditional childspacing practices of postpartum abstinence and prolonged breastfeeding, or from decline in levels of pathological sterility in response to public health measures.

The "missing girls" of China and the unintended consequences of the one child policy.

Abstract: High ratios of males to females in China have concerned researchers (Sen 1990, Yi et al. 1993) and their recent increase has alarmed policymakers worldwide. This paper presents an analysis of China's census data that indicates that the "missing girls" phenomenon is causally linked to enforcement of the One Child Policy. Fertility is lower and sex ratios are higher among those under stricter fertility control, and the overall increase in the sex ratio is driven

Are Tests of Sperm DNA Damage Clinically Useful? Pros and Cons

Abstract: The advent of assisted reproductive technologies, particularly intracytoplasmic sperm injection (ICSI), has revolutionized the treatment of male-factor infertility. However, there are many unanswered questions regarding the safety of these techniques. These safety concerns are relevant because 1) these technologies often bypass the barriers to natural selection; 2) infertile men, particularly those with severe male-factor infertility, possess substantially more sperm DNA damage than do fertile men; and 3) experimentally, sperm DNA damage has been shown to adversely affect the developing embryo. This review discusses the etiology of sperm DNA damage, describes the individual tests of sperm DNA damage, and explores the relationship between sperm DNA damage and pregnancy outcomes. Based on a systematic review of the literature, sperm DNA damage is associated with lower natural, intrauterine insemination (IUI), and in vitro fertilization (IVF) pregnancy rates, but not with ICSI pregnancy rates. The literature also suggests that that sperm DNA damage is associated with an increased risk of pregnancy loss in those couples undergoing IVF or ICSI. Nonetheless, the true clinical utility of sperm DNA damage tests remains to be established, because the available studies are small and few in number and the study characteristics are heterogeneous. Although current data suggest that impaired sperm DNA integrity may have the greatest effect on IUI pregnancy rates and pregnancy loss by IVF and ICSI, further prospective studies are needed before testing should become a routine part of patient management.

Changing relationships between education and fertility – a study of women and men born 1940-64

Abstract: Surprisingly, relatively little is known about the relationship between education and completed fertility in low fertility countries and especially the trend in this relationship over time. An inverse relationship is expected, but the topic has been left largely unexplored for at least a generation, and for men the topic is almost completely unexplored empirically. In this paper, we use data from the population registers covering all Norwegians born 1940-64. Among women, the relationship between completed fertility and the educational level attained at age 39 has become substantially less negative. In all the cohorts, better educated women have more often remained childless than the less educated, and they have had later first births, which also contributes to lower subsequent fertility. However, the negative effect of education on higher-order birth rates net of this impact of later motherhood has disappeared in the younger cohorts. Family-friendly policies and ideologies, leading, for example, to better access to high-quality day care, are likely the main engine behind this shift. Among men, a positive relationship has emerged. The better educated become fathers later than others, but fewer remain childless, and there has been an increasingly stimulating effect of education on second- and third-birth rates. We discuss these sex differences in the light of the persistent differences between mother and father roles.