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Fertility
Fertility in colloquial terms refers the ability to have offspring. In demographic contexts, fertility refers to the actual production of offspring, rather than the physical capability to reproduce, which is termed fecundity. The fertility rate is the average number of children born during an individual's lifetime. In medicine, fertility refers to the ability to have children, and infertility refers to difficulty in reproducing naturally. In general, infertility or subfertility in humans is defined as not being able to conceive a child after one year (or longer) of unprotected sex. The antithesis of ''fertility'' is infertility, while the antithesis of ''fecundity'' is sterility. Demography In demographic contexts, fertility refers to the actual production of offspring, rather than the physical capability to produce which is termed fecundity. While fertility can be measured, fecundity cannot be. Demographers measure the fertility rate in a variety of ways, which can be broa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Total Fertility Rate
The total fertility rate (TFR) of a population is the average number of children that are born to a woman over her lifetime, if they were to experience the exact current age-specific fertility rates (ASFRs) through their lifetime, and they were to live from birth until the end of their reproductive life. As of 2023, the total fertility rate varied widely across the world, from 0.7 in South Korea, to 6.1 in Niger. Among sovereign countries that were not city states or had a very small number of inhabitants, in 2024 the following countries had a TFR of 1.0 or lower: South Korea, Taiwan, and Ukraine; the following countries had a TFR of 1.2 or lower: Chile, China, Japan, Malta, Poland, and Spain. Fertility tends to be inversely correlated with levels of economic development. Historically, developed countries have significantly lower fertility rates, generally correlated with greater wealth, education, urbanization, and other factors. Conversely, in least developed countries, ferti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Infertility
In biology, infertility is the inability of a male and female organism to Sexual reproduction, reproduce. It is usually not the natural state of a healthy organism that has reached sexual maturity, so children who have not undergone puberty, which is the body's start of fertility, reproductive capacity, are excluded. It is also a normal state in women after menopause. In humans, ''infertility'' is defined as the inability to become pregnant after at least one year of unprotected and regular sexual intercourse involving a male and female partner. There are many causes of infertility, including some that Assisted reproductive technology, medical intervention can treat. Estimates from 1997 suggest that worldwide about five percent of all heterosexual couples have an unresolved problem with infertility. Many more couples, however, experience involuntary childlessness for at least one year, with estimates ranging from 12% to 28%. Male infertility is responsible for 20–30% of infert ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Income And Fertility
Income and fertility is the association between monetary gain on one hand, and the tendency to produce offspring on the other. There is generally an inverse correlation between income and the total fertility rate within and between nations. The higher the degree of education and GDP per capita of a human population, subpopulation or social stratum, the fewer children are born in any developed country. In a 1974 United Nations population conference in Bucharest, Karan Singh, a former minister of population in India, illustrated this trend by stating "Development is the best contraceptive." In 2015, this thesis was supported by Vogl, T.S., who concluded that increasing the cumulative educational attainment of a generation of parents was by far the most important predictor of the inverse correlation between income and fertility based on a sample of 48 developing countries. Generally a developed country has a lower fertility rate while a less economically developed country has a hi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crude Birth Rate
Birth rate, also known as natality, is the total number of live human births per 1,000 population for a given period divided by the length of the period in years. The number of live births is normally taken from a universal registration system for births; population counts from a census, and estimation through specialized demographic techniques such as population pyramids. The birth rate (along with mortality and migration rates) is used to calculate population growth. The estimated average population may be taken as the mid-year population. When the crude death rate is subtracted from the crude birth rate (CBR), the result is the rate of natural increase (RNI). This is equal to the rate of population change (excluding migration). The total (crude) birth rate (which includes all births)—typically indicated as births per 1,000 population—is distinguished from a set of age-specific rates (the number of births per 1,000 persons, or more usually 1,000 females, in each age ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Age And Female Fertility
Female fertility is affected by ageing, age and is a major fertility factor (demography), fertility factor for women. A woman's fertility is in generally good quality from the late teens to early thirties, although it declines gradually over time. Around 35, fertility is noted to decline at a more rapid rate. At age 45, a woman starting to try to conceive will have no live birth in 50–80 percent of cases. Menopause, or the cessation of menstrual periods, generally occurs in the 40s and 50s and marks the cessation of fertility, although age-related infertility can occur before then. The relationship between age and female fertility is sometimes referred to as a woman's "biological clock." Quantification of effect In adolescence The average age of a girl's first period (menarche) is 12 to 13 (12.5 years in the United States, 12.72 in Canada, 12.9 in the UK) but, in postmenarchal girls, about 80% of the cycles are anovulatory in the first year after menarche, which declines to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intelligence And Fertility
The relationship between fertility and intelligence has been investigated in many demographic studies. There is evidence that, on a population level, measures of intelligence such as educational attainment and literacy are negatively correlated with fertility rate in some contexts. Early views and research The negative correlation between fertility and intelligence (as measured by IQ) has been argued to be persistent and systematic in many parts of the modern West in particular. Early studies, however, are sometimes claimed to have been "superficial and illusory" and not clearly supported by the limited data they collected. Some of the first studies into the subject were carried out on individuals living before the advent of IQ testing, in the late 19th century, by looking at the fertility of men listed in Who's Who, these individuals being presumably of high intelligence. These men, taken as a whole, had few children, implying a correlation. This common objection, however, does ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Female Labor Participation
Since the Industrial Revolution, participation of women in the workforce outside the home has increased in industrialized nations, with particularly large growth seen in the 20th century. Largely seen as a boon for industrial society, women in the workforce contribute to a higher national economic output as measure in GDP as well as decreasing labor costs by increasing the labor supply in a society. Women's lack of access to higher education had effectively excluded them from the practice of well-paid and high status occupations. Entry of women into the higher professions, like law and medicine, was delayed in most countries due to women being denied entry to universities and qualification for degrees. For example, Cambridge University only fully validated degrees for women late in 1947, and even then only after much opposition and acrimonious debate. Women were largely limited to low-paid and poor status occupations for most of the 19th and 20th centuries, or earned less pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Demography
Demography () is the statistical study of human populations: their size, composition (e.g., ethnic group, age), and how they change through the interplay of fertility (births), mortality (deaths), and migration. Demographic analysis examines and measures the dimensions and dynamics of populations; it can cover whole societies or groups defined by criteria such as education, nationality, religion, and ethnicity. Educational institutions usually treat demography as a field of sociology, though there are a number of independent demography departments. These methods have primarily been developed to study human populations, but are extended to a variety of areas where researchers want to know how populations of social actors can change across time through processes of birth, death, and migration. In the context of human biological populations, demographic analysis uses administrative records to develop an independent estimate of the population. Demographic analysis estima ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Reproduction
Human sexual reproduction, to produce offspring, begins with fertilization. Successful reproduction typically involves sexual intercourse between a healthy, sexually mature and fertile male and female. During sexual intercourse, sperm cells are ejaculated into the vagina through the penis, resulting in fertilization of an ovum to form a zygote. While normal cells contain 46 chromosomes (23 pairs), gamete cells contain only half that number, and it is when these two cells merge into one combined zygote cell that genetic recombination occurs. The zygote then undergoes a defined development process that is known as human ''embryogenesis'', and this starts the typical 38-week gestation period for the embryo (and eventually foetus) that is followed by childbirth. Assisted reproductive technology also exists, like IVF, some of which involve alternative methods of fertilization, which do not involve sexual intercourse; the fertilization of the ovum may be achieved by artificia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paternal Age Effect
The paternal age effect is the statistical relationship between the father's age at conception and biological effects on the child. Such effects can relate to birthweight, congenital disorders, life expectancy, and psychological outcomes. A 2017 review found that while severe health effects are associated with higher paternal age, the total increase in problems caused by paternal age is low. Average paternal age at birth reached a low point between 1960 and 1980 in many countries and has been increasing since then, but has not reached historically unprecedented levels. The rise in paternal age is not seen as a major public health concern. The genetic quality of sperm, as well as its volume and motility, may decrease with age, leading the population geneticist James F. Crow to claim that the "greatest mutational health hazard to the human genome is fertile older males". The paternal age effect was first proposed implicitly by physician Wilhelm Weinberg in 1912 and explicitly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sexual Intercourse
Sexual intercourse (also coitus or copulation) is a sexual activity typically involving the insertion of the Erection, erect male Human penis, penis inside the female vagina and followed by Pelvic thrust, thrusting motions for sexual pleasure, sexual reproduction, reproduction, or both.Sexual intercourse most commonly means penile–vaginal penetration for sexual pleasure or sexual reproduction; dictionary sources state that it especially means this, and scholarly sources over the years agree. See, for example; * * * * * * * * This is also known as vaginal intercourse or vaginal sex. Sexual penetration is an instinctive form of sexual behaviour and psychology among humans. Other forms of sexual penetration, penetrative sexual intercourse include anal sex (penetration of the Human anus, anus by the penis), oral sex (penetration of the mouth by the penis or oral penetration of the female genitalia), Fingering (sexual act), fingering (sexual penetration by the fingers) and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
