Natural fertility

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Natural fertility is the fertility that exists without birth control or other medical interventions. The control is the number of children birthed to the parents and is modified as the number of children reaches the maximum. Natural fertility tends to decrease as a society modernizes. Women in a pre-modernized society typically have given birth to a large number of children by the time they are 50 years old, while women in post-modernized society only bear a small number by the same age. [1] However, during modernization natural fertility rises, before family planning is practiced. [2]

Contents

Historical populations have traditionally honored the idea of natural fertility by displaying fertility symbols. [3]

Birth control

Natural fertility is a concept developed by the French historical demographer Louis Henry to refer to the level of fertility that would prevail in a population that makes no conscious effort to limit, regulate, or control fertility, so that fertility depends only on physiological factors affecting fecundity. In contrast, populations that practice birth control will have lower fertility levels as a result of delaying first births (a lengthened interval between menarche and first pregnancy), extended intervals between births, or stopping child-bearing at a certain age. Such control does not assume the use of artificial means of fertility regulation or modern contraceptive methods but can result from the use of traditional means of contraception or pregnancy prevention (e.g., coitus interruptus). Many social norms or practices affect fertility regulation including celibacy, the age at marriage and the timing and frequency of sexual intercourse, including periods of prescribed sexual abstinence. Breastfeeding has also been used to space births in areas without birth control. [4] Ansley Coale and other demographers have developed several methods for measuring the extent of such fertility control, in which the idea of a natural level of fertility is an essential component. [5]

When women have access to birth control, they can better plan their pregnancies. This leads to better health outcomes and enhances their lives and those of their families. Birth control has dramatically improved the ability of all women to participate actively and with dignity in economies across the world. [6] Birth control allows many women to delay childbearing until they believe they are emotionally, physically and financially ready to be a parent. Children who are born in an unplanned pregnancy tend to occur outside relationships. Birth Control has been the main tool to prevent unplanned births, and with greater access to birth control unplanned pregnancies have declined. [7]

Proximate determinants

The 28-day menstrual cycle is depicted; the cycle starts at the onset of the age at menarche. MenstrualCycle.png
The 28-day menstrual cycle is depicted; the cycle starts at the onset of the age at menarche.

Proximate determinants describe variables that affect a female's fertility. There are seven proximate determinants of natural fertility, four of which affect the inter-birth interval: [8]

This picture portrays the different stages a woman will experience between first becoming fertile at menarche through menopause. The different colors on the graph represent different things as well. The red stands for areas relating to a woman's menstrual cycle, the green represents marriage, blue means birth, and black regards menopause and conception at different areas of the diagram. The purple arrows show the period of gestation following conception, and the orange arrows show lactational infecundability. Proximate Determinants Diagram .png
This picture portrays the different stages a woman will experience between first becoming fertile at menarche through menopause. The different colors on the graph represent different things as well. The red stands for areas relating to a woman's menstrual cycle, the green represents marriage, blue means birth, and black regards menopause and conception at different areas of the diagram. The purple arrows show the period of gestation following conception, and the orange arrows show lactational infecundability.

Factors like the age at which a woman marries and the inter-birth interval are influenced by social factors like education, religion, and wealth. Educated women tend to delay childbirth and have fewer offspring. [9] In sub-Saharan Africa where gender disparities in education are more prevalent, fertility rates are the highest in the world. [10] Globally, 58 million girls do not attend primary school. Half of those girls live in sub-Saharan Africa; this disparity only widens as the level of education increases. [11] Prevalence of child marriage is an attributing factor to the fertility rates in India as women ages 20–24 reported that they had never used contraception prior to giving birth or within their first year of marriage. Child marriage in India primarily occurs in girls living in poor socioeconomic conditions. Furthermore, women married as minors in South Asia, where half of child marriages occur, reveal having high numbers of unwanted pregnancies than their counterparts that married as adults. [12]

Practicing natural fertility

Some tribes of the San people are considered to practice natural fertility because they do not use any forms of birth control Namibian Bushmen Girls.JPG
Some tribes of the San people are considered to practice natural fertility because they do not use any forms of birth control

Populations in practice

The three main reasons for practicing natural fertility include financial status, accessibility to family planning, and religious influences. The three main reasons for practicing natural fertility.png
The three main reasons for practicing natural fertility include financial status, accessibility to family planning, and religious influences.

Reasons for practice

Common reasons communities or individuals will practice natural fertility include concerns about developing medical conditions (including future infertility), pre-existing health conditions (including PCOS), cost of birth control, religious prohibition, lack of availability of birth control, and lack of information about birth control methods. Location also tends to be a factor in regards to the availability of both contraceptives and education on sexual practice. For example, less developed areas, including, but not limited to those extending throughout inland Africa lack access to the drugs necessary to control fertility or informative lessons describing their correct usage. [14]

Influences on natural fertility rates

Fertile window

The number of children born to one woman can vary dependent on her window from menarche to menopause. The average window of fertility is from 13.53 to 49.24. [15] Taking into consideration lactational amenorrhea and the period between conception and birth, the average woman is capable of experiencing around 20 births. However, if the duration of lactation is cut short due to use of a formula substitute or the woman has multiple births, the number of offspring could exceed 20.

Male contribution

Natural fertility is not only influenced by women and their conscious or unconscious decisions, but also their male counterparts. Even if a woman does not take contraceptives, lacks knowledge of family planning, or does not practice regulated fertility, she might not be able to conceive. Over the past half century, there has been an increase in scientific data supporting the decline in male sperm count. [16] The decrease is attributed to various environmental toxins that are accumulating as the planet continues to industrialize. If sperm count remains above 60 million per ejaculate, fertility remains normal. But sperm counts are continuing to drop. At such low levels, the sperm often are incapable of successfully fertilizing the egg. A decline in male fertility often means a decline in natural fertility, as fertility is carried by both sexes.

Preconditions for fertility decline

Ansley J. Coale developed a theory to predict when a population's fertility would begin to decline. His theory focused on three specific aspects. First, a couple must make conscious choice to control their fertility. This is closely related to secularization as some religions prohibit means of contraception. Second, there must be a benefit to controlling fertility that results in the desire for a smaller family. For example, as more regions move away from agriculture children are no longer needed to help with labor and fertility rates and family size tend to decrease. Third, the couple must be able to control fertility. This means that access to contraceptives or other means of limiting fertility must be available. [17]

Coale's preconditions for fertility decline is interrelated to the Demographic Transition, a theory of the transition of societies from an agricultural to an industrial system. A more modernized society has lower mortality and fertility rates while a less modernized society tends to have higher mortality and fertility rates. [18] Developing countries in the early stages of the demographic transition are characterized by high fertility and mortality rates which can be attributed to the lack of medical interventions like birth control and modern technology. [19] Communicable diseases and contaminated resources like water and consequently food, plague developing countries. As a consequence, people of all ages die in masses. Coale's theory favored a fertility decline as a smaller population would allow for a more beneficial spread of resources and keep the number of ill individuals concentrated to a smaller group. In addition, Coale viewed the development of Europe's infrastructure during the Industrial Revolution as a mark in its transition in the demographic transition. Mortality and fertility rates declined with their improved standard of living. [18] Infant mortality rates are indicative of fertility rates as couples decide to have a lot children knowing that a number of them will die so that even after those children die, they have sufficient kids to aid in agricultural work. Conversely, developed countries in the later stages of the demographic transition experience lower fertility and mortality rates due to the accessibility of contraception, the pursuit of higher education in women, and marriage at a later age. [19]

Coale's theory can be observed in sub-Saharan Africa as countries residing within this region have fertility levels that are declining at a much slower rate than before and have one of the highest projected population growths compared to other areas of the world. [10] Individuals inhabiting sub-Saharan Africa have slowly rejected Coale's second precondition for fertility decline which, as stated before, is willingness. They are resistant and unwilling to accept the integration of modern forms of contraception. This can be attributed to the influence of religion and the values it imposes on culture even in individuals who don't practice any religion. [20] To add on, the society they live in encourages young marriages and values large families. Despite the discrepancy between preferred child bearing and natural fertility, women in Africa have reported they don't use any form of contraception to prevent pregnancies. [21] All of these factors have contributed to the slowing down of fertility decline in Africa. As of now, an uninterrupted African baby boom is to be expected. [22]

Related Research Articles

Coitus interruptus, also known as withdrawal, pulling out or the pull-out method, is an act of birth control during penetrative sexual intercourse, whereby the penis is withdrawn from a vagina prior to ejaculation so that the ejaculate (semen) may be directed away in an effort to avoid insemination.

<span class="mw-page-title-main">Teenage pregnancy</span> Childbirth in human females under the age of 20

Teenage pregnancy, also known as adolescent pregnancy, is pregnancy in a female under the age of 20.

In demography, demographic transition is a phenomenon and theory which refers to the historical shift from high birth rates and high death rates to low birth rates and low death rates, as societies attain more technology, education and economic development. The demographic transition has occurred in most of the world over the past two centuries, bringing the unprecedented population growth of the post-Malthusian period, then reducing birth rates and population growth significantly in all regions of the world. The demographic transition strengthens economic growth process by three changes: (i) reduced dilution of capital and land stock, (ii) increased investment in human capital, and (iii) increased size of the labor force relative to the total population and changed age population distribution. Although this shift has occurred in many industrialized countries, the theory and model are frequently imprecise when applied to individual countries due to specific social, political and economic factors affecting particular populations.

<span class="mw-page-title-main">Family planning</span> Planning when to have children

Family planning is the consideration of the number of children a person wishes to have, including the choice to have no children, and the age at which they wish to have them. Things that may play a role on family planning decisions include marital situation, career or work considerations, financial situations. If sexually active, family planning may involve the use of contraception and other techniques to control the timing of reproduction.

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 of unprotected sex. The antithesis of fertility is infertility, while the antithesis of fecundity is sterility.

<span class="mw-page-title-main">Birth rate</span> Total number of live births per 1,000 divided by time period

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. The birth rate is used to calculate population growth. The estimated average population may be taken as the mid-year population.

<span class="mw-page-title-main">Total fertility rate</span> Number of children a woman is expected to have barring select circumstances

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.

<span class="mw-page-title-main">Sub-replacement fertility</span> Total fertility rate that (if sustained) leads to each new generation being less populous

Sub-replacement fertility is a total fertility rate (TFR) that leads to each new generation being less populous than the older, previous one in a given area. The United Nations Population Division defines sub-replacement fertility as any rate below approximately 2.1 children born per woman of childbearing age, but the threshold can be as high as 3.4 in some developing countries because of higher mortality rates. Taken globally, the total fertility rate at replacement was 2.33 children per woman in 2003. This can be "translated" as 2 children per woman to replace the parents, plus a "third of a child" to make up for the higher probability of males born and mortality prior to the end of a person's fertile life. In 2020, the global average fertility rate was around 2.4 children born per woman.

Male contraceptives, also known as male birth control, are methods of preventing pregnancy by interrupting the function of sperm. The main forms of male contraception available today are condoms, vasectomy, and withdrawal, which together represented 20% of global contraceptive use in 2019. New forms of male contraception are in clinical and preclinical stages of research and development, but as of 2024, none have reached regulatory approval for widespread use.

<span class="mw-page-title-main">Sexual and reproductive health</span> State of the reproductive system without evidence of disease, disorders, or deficiencies

Sexual and reproductive health (SRH) is a field of research, health care, and social activism that explores the health of an individual's reproductive system and sexual well-being during all stages of their life. Sexual and reproductive health is more commonly defined as sexual and reproductive health and rights, to encompass individual agency to make choices about their sexual and reproductive lives.

<span class="mw-page-title-main">Comparison of birth control methods</span>

There are many methods of birth control that vary in requirements, side effects, and effectiveness. As the technology, education, and awareness about contraception has evolved, new contraception methods have been theorized and put in application. Although no method of birth control is ideal for every user, some methods remain more effective, affordable or intrusive than others. Outlined here are the different types of barrier methods, hormonal methods, various methods including spermicides, emergency contraceptives, and surgical methods and a comparison between them.

Childlessness is the state of not having children. Childlessness may have personal, social or political significance.

Ansley Johnson Coale, was one of America's foremost demographers. A native to Baltimore, Maryland, he earned his Bachelor of Arts in 1939, his Master of Arts in 1941, and his Ph.D. in 1947, all at Princeton University. A long-term director of the Office of Population Research at Princeton, Coale was especially influential for his work on the demographic transition and for his leadership of the European Fertility Project.

<span class="mw-page-title-main">Prevalence of teenage pregnancy</span> Overview of the prevalence of teenage pregnancy around the world

Western and non-Western countries have distinctly different rates of teenage pregnancy. In Western countries such as the United States, Canada, Western Europe, Australia, and New Zealand, teen parents tend to be unmarried, and adolescent pregnancy is seen as a social issue.

<span class="mw-page-title-main">Birth control</span> Method of preventing human pregnancy

Birth control, also known as contraception, anticonception, and fertility control, is the use of methods or devices to prevent unintended pregnancy. Birth control has been used since ancient times, but effective and safe methods of birth control only became available in the 20th century. Planning, making available, and using human birth control is called family planning. Some cultures limit or discourage access to birth control because they consider it to be morally, religiously, or politically undesirable.

<span class="mw-page-title-main">Missing women</span> Fewer women than expected in a population

The term "missing women" indicates a shortfall in the number of women relative to the expected number of women in a region or country. It is most often measured through male-to-female sex ratios, and is theorized to be caused by sex-selective abortions, female infanticide, and inadequate healthcare and nutrition for female children. It is argued that technologies that enable prenatal sex selection, which have been commercially available since the 1970s, are a large impetus for missing female children.

<span class="mw-page-title-main">Family planning in India</span>

Family planning in India is based on efforts largely sponsored by the Indian government. From 1965 to 2009, contraceptive usage has more than tripled and the fertility rate has more than halved, but the national fertility rate in absolute numbers remains high, causing concern for long-term population growth. India adds up to 1,000,000 people to its population every 20 days. Extensive family planning has become a priority in an effort to curb the projected population of two billion by the end of the twenty-first century.

Fertility factors are determinants of the number of children that an individual is likely to have. Fertility factors are mostly positive or negative correlations without certain causations.

<span class="mw-page-title-main">Birth control in Africa</span>

Access to safe and adequate sexual and reproductive healthcare constitutes part of the Universal Declaration of Human Rights, as upheld by the United Nations.

Human reproductive ecology is a subfield in evolutionary biology that is concerned with human reproductive processes and responses to ecological variables. It is based in the natural and social sciences, and is based on theory and models deriving from human and animal biology, evolutionary theory, and ecology. It is associated with fields such as evolutionary anthropology and seeks to explain human reproductive variation and adaptations. The theoretical orientation of reproductive ecology applies the theory of natural selection to reproductive behaviors, and has also been referred to as the evolutionary ecology of human reproduction.

References

Notes
  1. ↑ Coale AJ (1989-01-01). "Demographic Transition". In Eatwell J, Milgate M, Newman P (eds.). Social Economics. The New Palgrave. Palgrave Macmillan UK. pp. 16–23. doi:10.1007/978-1-349-19806-1_4. ISBN   978-0-333-49529-2.
  2. ↑ Romaniuk A (1980-07-01). "Increase in natural fertility during the early stages of modernization: evidence from an African case study, Zaire". Population Studies. 34 (2): 293–310. doi:10.1080/00324728.1980.10410391. PMID   11636724.
  3. ↑ Hull V, Simpson M (1985-01-01). "Breastfeeding child health and child-spacing: cross-cultural perspectives". Popline. 3 (2). United States Agency for International Development (USAID): 63–65.
  4. ↑ See, e.g., Anderson, Barbara A.; Silver, Brian D. (1992). "A simple measure of fertility control". Demography. 29 (3): 343–56. doi: 10.2307/2061822 . JSTOR   2061822. PMID   1426433.
  5. ↑ Richards C (March 2016). "Protecting and Expanding Access to Birth Control". The New England Journal of Medicine. 374 (9): 801–3. doi:10.1056/nejmp1601150. PMID   26962898.
  6. ↑ Haskins R, Sawhill I, McLanahan S (28 March 2017). "The Promise of Birth Control". Future of Children Fall 2015: 1. General Reference Center GOLD.
  7. ↑ Wood JW (December 31, 1994). Dynamics of Human Reproduction: Biology, Biometry, Demography . Piscataway, New Jersey: Aldine Transaction. ISBN   978-0-202-01180-6.
  8. ↑ Reading BF (May 12, 2011). "Data Highlights". Earth Policy.
  9. 1 2 Cleland JG, Ndugwa RP, Zulu EM (November 4, 2010). "Family planning in sub-Saharan Africa: progress or stagnation?". Bulletin of the World Health Organization. 89 (2): 137–143. doi:10.2471/blt.10.077925. ISSN   0042-9686. PMC   3040375 . PMID   21346925.
  10. ↑ United Nations Statistics Division. "The World's Women 2015". unstats.un.org.
  11. ↑ Raj A, Saggurti N, Balaiah D, Silverman JG (May 2009). "Prevalence of child marriage and its effect on fertility and fertility-control outcomes of young women in India: a cross-sectional, observational study". Lancet. 373 (9678): 1883–9. doi:10.1016/S0140-6736(09)60246-4. PMC   2759702 . PMID   19278721.
  12. ↑ Konner, Melvin; Shostak, Marjorie (1987). "Timing And Management Of Birth Among The !Kung". Cultural Anthropology. 2 (1). American Anthropological Association: 11–28. doi: 10.1525/can.1987.2.1.02a00030 . ISSN   1548-1360 . Retrieved 2023-04-14– via eHRAF.
  13. ↑ "Population explosion". The Economist. ISSN   0013-0613 . Retrieved 2016-03-04.
  14. ↑ Thomas F, Renaud F, Benefice E, de Meeüs T, Guegan JF (April 2001). "International variability of ages at menarche and menopause: patterns and main determinants". Human Biology. 73 (2): 271–90. CiteSeerX   10.1.1.418.1084 . doi:10.1353/hub.2001.0029. JSTOR   41465935. PMID   11446429. S2CID   12330919.
  15. ↑ Martin R (May 21, 2013). "Sperm Count Updated". Psychology Today. Sussex Publishers, LLC. Retrieved March 3, 2016.
  16. ↑ Coale AJ, Watkins SC (1986). The decline of fertility in Europe: the revised proceedings of a Conference on the Princeton European Fertility Project. Princeton, N.J.: Princeton University Press. ISBN   978-0-691-09416-8.
  17. 1 2 Coale AJ (1984). "The Demographic Transition" (PDF). Pakistan Development Review. 23 (4): 531–552. doi:10.30541/v23i4pp.531-552 (inactive 1 November 2024). PMID   12280194. S2CID   39280113. Archived from the original (PDF) on 2018-04-12.{{cite journal}}: CS1 maint: DOI inactive as of November 2024 (link)
  18. 1 2 Nargund G (2009). "Declining birth rate in Developed Countries: A radical policy re-think is required". Facts, Views & Vision in ObGyn. 1 (3): 191–3. PMC   4255510 . PMID   25489464.
  19. ↑ "Religion, contraception and abortion factsheet". FPA. 2013-06-15. Retrieved 2018-03-15.
  20. ↑ "Family Planning in West Africa – Population Reference Bureau". www.prb.org. Retrieved 2018-04-05.
  21. ↑ "What to do about Africa's dangerous baby boom". The Economist. ISSN   0013-0613 . Retrieved 2024-03-21.
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