Iran hope with such a comprehensive population policies and inter sectored collaboration which is necessary for implementing of Population policy decree achieve fertility replacement level and improving maternal, newborns and children health. Citation: Eslami M. J Fam Reprod Health ; 10 4 : National Center for Biotechnology Information , U.
J Family Reprod Health. Mohammad Eslami , M. Author information Article notes Copyright and License information Disclaimer.
Correspondence: Mohammad Eslami moc. This article has been cited by other articles in PMC. Some of them are as below: Age of marriage among Iranian girls and boys is in the increasing trend and it has been increased to Notes: Citation: Eslami M. References 1. Bellieni C. Pregnancy and Undue Pressures. J Fam Reprod Health. International Journal of Preventive Medicine. Prevalence of Primary Infertility in Iran in Iranian Journal of Public Health.
The TFR is the most widely used fertility measure in program impact evaluations for two main reasons: 1 it is unaffected by differences or changes in age-sex composition, and 2 it provides an easily understandable measure of hypothetical completed fertility.
TFR includes only live births. The TFR is only a hypothetical measure of completed fertility, and thus women of reproductive age at any given point in time could have completed family sizes considerably different from that implied by a current TFR, should age-specific fertility rates rise or fall in the future.
As was also the case for the ASFR, the TFR may be computed for women who were continuously married or in union during the reference period of the measure in order to decrease the potentially confounding effects of differences in exposure to the risk of pregnancy to the extent that differences are associated with marital status.
In these countries, fertility rates are higher due to the lack of access to contraceptives and generally lower levels of female education. The social structure, religious beliefs, economic prosperity and urbanisation within each country are likely to affect birth rates as well as abortion rates, Developed countries tend to have a lower fertility rate due to lifestyle choices associated with economic affluence where mortality rates are low, birth control is easily accessible and children often can become an economic drain caused by housing, education cost and other cost involved in bringing up children.
Higher education and professional careers often mean that women have children late in life. This can result in a demographic economic paradox. The Total Fertility Rate TFR of a population is the average number of children that would be born to a woman over her lifetime if she were to experience the exact current age specific fertility rates through her life time and she were to survive from birth through the end of her reproductive life.
It is obtained by summing the single year age specific rates for a given time point. Perhaps more relevant to the current debate is the replacement fertility rate which is the total fertility rate in which women would have only enough children to replace themselves and their partners. Effectively it is the total fertility rate at which newborn girls would have an average of exactly 1 daughter over their lifetimes. By definition replacement is only considered to have occurred when the offspring reach 15 years of age.
The replacement fertility rate is roughly 2. Due to increased mortality rates, the approximate average for developing regions of the world is 2.
At this rate, population growth through reproduction will be approximately 0, but still be affected by male-female ratios and mortality rates. The fertility of the population of the United States is below replacement among those native born, and above replacement among immigrant families and the socially deprived Singh et al. However the fertility rates of immigrants to the US have been found to decrease sharply in the second generation as a result of improving education and income.
It will take several generations for a real change in total fertility rates to be reflected in birth rates because the age distribution must reach equilibrium. For example, a population that has recently dropped below replacement fertility rate continues to grow because the recent high fertility produced large number of young couples who would now be in their child bearing years.
The phenomenon carries forward for several generations and is called population momentum or population lag effect. The time lag effect is of great importance to human population growth rates. The state policy institutes and international population studies are closely monitoring how reproductive patterns cause immigrant generations globally.
Although recent data show that birth rates in the UK have increased Office of National Statistics, , this is predominantly due to immigration so there are still serious concerns about long term replacement.
There are two potential means of addressing the problem of providing a young productive workforce able to generate income to provide the social care for the old and infirm. The first is to find ways of increasing the birth rate; this is essentially a long term solution but one which should provide more steady and predictable results. The second is to encourage immigration of a predominantly young and skilled workforce; this may provide an instant answer to the problem but is likely to be short-term unless the immigrants decide to stay in large numbers.
In the long term it is doubtful whether reliance should be placed on immigration to solve an intrinsic societal problem in developed nations, namely a falling birth rate. The declining birth rate is not unique to Britain and Western European countries. Countries like Japan have a similar concern.
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