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Information about Fertility

Fertility is the natural capability of giving life. As a measure, "Fertility Rate" is the number of children born per couple, person or population. This is different to fecundity, which is defined as the potential for reproduction (influenced by gamete production, fertilisation and carrying a pregnancy to term). In the English language, the term was originally applied only to females, but increasingly is applied to males as well, as common understanding of reproductive mechanisms increases and the importance of the male role is better known. Infertility is a deficient fertility.

Human fertility depends on factors of nutrition, sexual behavior, culture, instinct, endocrinology, timing, economics, way of life, and emotions. Animal fertility is no less complex, and may display astounding mechanisms.

Agriculture

See also arable land, soil fertility, harvest, Neolithic revolution.
Fertility is also applied to farmlands and plants, where it implies a capacity to yield large crops of sound fruits, seeds or vegetables.

Demographics

The fertility rate is a demographic measure of the number of children per woman. Although it has been until recently considered to be a fairly reliable indicator of population growth, it is no longer so in much of Asia. Due to selective abortion and other factors, the ratio of women relative to men in populations is declining. Therefore, the fertility rate as it has traditionally been defined is no longer an authoritative measure of population growth in China, India, and Myanmar.

Human fertility

Both women and men have hormonal cycles which determine both when a woman can achieve pregnancy and when a man is most fertile. The female cycle is approximately twenty-eight days long, but the male cycle is variable. Men can ejaculate and produce sperm at any time of the month, but their sperm quality dips occasionally, which scientists guess is in relation to their internal cycle.

Furthermore, age also plays a role, especially for women.

Menstrual cycle

Main article: Menstrual cycle#The fertile window
Women are fertile only about seven days in each menstrual cycle. Ovulation occurs at about the fourteenth day of their menstrual cycle, this obviously being the most fertile time for females. The exact point of ovulation depends, however[1]. If the egg is not fertilized by the male’s sperm, the egg will break down within 1–2 days into its components (mostly protein) and be reabsorbed by the body. However, sperm can survive inside the uterus for five days. Thus, a successful conception can result during seven days of the female cycle; five days before and two days after ovulation.

Female fertility after 30

Women's fertility peaks in their early teens, and often deteriorates after 30. Of women trying to get pregnant, without using fertility drugs or in vitro fertilization:
  • At age 30, 75% will get pregnant within one year, and 91% within four years.
  • At age 35, 66% will get pregnant within one year, and 84% within four years.
  • At age 40, 44% will get pregnant within one year, and 64% within four years.[2]
The above figures are for pregnancies ending in a live birth and take into account the increasing rates of miscarriage in the ageing population. According to the March of Dimes, "about 9 percent of recognised pregnancies for women aged 20 to 24 ended in miscarriage. The risk rose to about 20 percent at age 35 to 39, and more than 50 percent by age 42".[3]

Birth defects, especially those involving chromosome number and arrangement, also increase with the age of the mother. According to the March of Dimes, "At age 25, a woman has about a 1-in-1,250 chance of having a baby with Down syndrome; at age 30, a 1-in-1,000 chance; at age 35, a 1-in-400 chance; at age 40, a 1-in-100 chance; and at 45, a 1-in-30 chance."[4]

The use of fertility drugs and/or in vitro fertilization can increase the chances of becoming pregnant at a later age. Successful pregnancies facilitated by fertility treatment have been documented in women as old as 67.[5]

Doctors recommend that women over 30 who have been unsuccessful in trying to conceive for more than 6 months undergo some kind of fertility testing [6].

See also

References

1. ^ Ovusoft.com
2. ^ Fertility Treatment Less Successful After 35. WebMD. Retrieved on July 4, 2006.
3. ^ Pregnancy After 35. March of Dimes. Retrieved on July 4, 2006.
4. ^ The sterility tax can be reestablished in Russia. Retrieved on September 22, 2006.
5. ^ Spanish woman ' is oldest mother'. BBC News. Retrieved on 2006-12-30.
6. ^ Fertility Testing (Female Fertility Testing)

Further reading

  • Bock, J. (2002). Evolutionary Theory and the Search for a Unified Theory of Fertility. American Journal of Human Biology 14(2) 145-148. Full text
 •  • [ e]
Physiology, endocrinology, sex: Reproductive physiology and endocrinology
Menstrual cycle/Estrous cycleMenstruation - Follicular phase - Ovulation - Luteal phase
GametogenesisSpermatogenesis -Oogenesis
SexualityHuman sexual behavior - Sexual intercourse - Erection - Ejaculation - Orgasm - Insemination - Fertilisation/Fertility - Masturbation - Pregnancy - Postpartum period
LifespanPrenatal development - Sexual dimorphism - Sexual differentiation - Puberty (Menarche, Adrenarche) - Maternal age/Paternal age - Climacteric (Menopause, Andropause)
EggsOviposition - Oviparity - Ovoviviparity - Viviparity
Fecundity, derived from the word , generally refers to the ability to reproduce. In biology and demography, fecundity is the potential reproductive capacity of an organism or population, measured by the number of gametes (eggs), seed set or asexual propagules.
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Female (♀) is the sex of an organism, or a part of an organism, which produces ova (egg cells). The ova are defined as the larger gametes in a heterogamous reproduction system, while the smaller, usually motile gamete, the spermatozoon is produced by the male.
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Male (♂) refers to the sex of an organism, or part of an organism, which produces small mobile gametes, called spermatozoa. Each spermatozoon can fuse with a larger female gamete or ovum, in the process of fertilisation.
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Infertility primarily refers to the biological inability of a man or a woman to contribute to conception. Infertility may also refer to the state of a woman who is unable to carry a pregnancy to full term.
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Nutrition is a science that examines the relationship between diet and health. Dietitians are health professionals who specialize in this area of study, and are trained to provide safe, evidence-based dietary advice and interventions.
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This article is about sexual practices (i.e., physical sex). Broader aspects of sexual behaviour such as social and psychological sexual issues are covered in related articles such as human sexuality, heterosexuality, and homosexuality.

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Culture (from the Latin cultura stemming from colere, meaning "to cultivate,") generally refers to patterns of human activity and the symbolic structures that give such activity significant importance.
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Instinct is the inherent disposition of a living organism toward a particular behavior. Instincts are unlearned, inherited fixed action patterns of responses or reactions to certain kinds of stimuli.
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Endocrinology is a branch of medicine dealing with disorders of the endocrine system and its specific secretions called hormones.

Function of endocrine organs, hormones and receptors

Hormones are molecules that act as signals from one type of cells to another.
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Economics is the social science that studies the production, distribution, and consumption of goods and services. The term economics comes from the Greek for oikos (house) and nomos (custom or law), hence "rules of the house(hold).
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emotion is a "complex reaction pattern, involving experiential, behavioral, and physiological elements, by which the individual attempts to deal with a personally significant matter of event.
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arable land (from Latin arare, to plough) is an agricultural term, meaning land that can be used for growing crops.

Of the earth's 148,000,000 km² (57 million square miles) of land, approximately 31,000,000 km² (12 million square miles) are arable;
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Soil fertility is the characteristic of soil that supports abundant plant life. In particular the term is used to describe agricultural and garden soil.

Fertile soil has the following properties:

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harvesting is the process of gathering mature crops from the fields. Reaping is the harvesting of grain crops. The harvest marks the end of the growing season, or the growing cycle for a particular crop.
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The Neolithic Revolution is the first agricultural revolution, describing the transition from nomadic hunting and gathering communities and bands, to agriculture and settlement, as first adopted by various independent prehistoric human societies, in numerous locations on
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arable land (from Latin arare, to plough) is an agricultural term, meaning land that can be used for growing crops.

Of the earth's 148,000,000 km² (57 million square miles) of land, approximately 31,000,000 km² (12 million square miles) are arable;
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fruit has different meanings depending on context. In botany, a fruit is the ripened ovary—together with seeds—of a flowering plant. In many species, the fruit incorporates the ripened ovary and surrounding tissues.
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SEEDS (The Sustainable Environment and Ecological Development Society) is a voluntary organisation registered under the Societies Act of India.

SEEDS was formed in 1994 as an informal group of students and pedagogues of the School of Planning and Architecture, New
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Vegetable is a term which generally refers to an edible part of a plant. The definition is traditional rather than scientific and is somewhat arbitrary and subjective. All parts of herbaceous plants eaten as food by humans, whole or in part, are normally considered vegetables.
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total fertility rate (TFR, sometimes also called the fertility rate, period total fertility rate (PTFR) or total period fertility rate (TPFR)) of a population is the average number of children that would be born to a woman over her lifetime if she were
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Demography is the statistical study of all populations. It can be a general science that can be applied to any kind of dynamic population, that is, one that changes over time or space (see population dynamics).
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child (plural: children) is primarily a boy or girl who has not reached puberty.[1][2] However, some youth reach puberty earlier or later than expected.
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population is the collection of people or organisms of a particular species living in a given geographic area or mortality, and migration, though the field encompasses many dimensions of population change including the family (marriage and divorce), public health, work and the
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Asia is the world's largest and most populous continent. It covers 8.6% of the Earth's total surface area (or 29.4% of its land area) and, with almost 4 billion people, it contains more than 60% of the world's current human population.
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hormone (from Greek όρμή - "to set in motion") is a chemical messenger that carries a signal from one cell (or group of cells) to another. All multicellular organisms produce hormones (including plants - see phytohormone).
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