Fertility is the natural capability to givelife. Inhumans andanimals, fertility means that theparent can produce babies.
More precisely, fertility is thecapacity of an individual orpopulation to produce viableoffspring.[1] By 'viable' is meant 'able to live and reproduce'.
Fertility can also be used as ametaphor: having a "fertile imagination" means being able to think of many new and interesting things.
As a measure,fertility rate is the number of children born per couple, or person or population. This is different tofecundity. This is defined as thepotential for reproduction (influenced bygamete production, fertilisation and carrying apregnancy to term. In English language, the term was originally applied only tofemales, but increasingly is applied to males as well, as common understanding ofreproductive mechanisms increases and the importance of themale role is better known.Infertility is a deficient fertility.
In theUnited States, the average age ofmenarche (first period) is about 12.5 years.[3] However, in most girls, menarche does not signal thatovulation has occurred. In postmenarchal girls, about 80% of the cycles areanovulatory in the first year after menarche, 50% in the third and 10% in the sixth year.[4] Women's fertility peaks between ages 22–26, and after 35 it starts to sharply decline.
Birth rates have been noted by Henri Leridon, PhD, as an epidemiologist with theFrench Institute of Health and Medical Research. Of women trying to get pregnant, without using fertility drugs orin vitro fertilization:
At age 30
75% will have a conception ending in a live birth within one year
91% will have a conception ending in a live birth within four years.
At age 35
66% will have a conception ending in a live birth within one year
84% will have a conception ending in a live birth within four years.
At age 40
44% will have a conception ending in a live birth within one year
64% will have a conception ending in a live birth within four years.[5][6]
The use offertility drugs and/orin vitro fertilization can increase the chances of becoming pregnant at a later age.[7]
There is evidence that male reproduction abilities are reduced with higher age.[8]Sperm count is becoming smaller with age, with men aged 50–80 years producing 75% of sperm compared with 20–50 years old males.If the sperm count is too low, a man could increase it with herbal and chemical supplements.[9]Even larger change can be seen in the number ofseminiferous tubules produced by males at different age stages:
In males 20–39 years old, 90% of the seminiferous tubules contain mature sperm.
In males 40–69 years old, 50% of the seminiferous tubules contain mature sperm.
In males 80 years old and older, 10% of the seminiferous tubules contain mature sperm.[10]
When a person is infertile it means that they are unable to have a child naturally. Infertility is define as the inability to fall pregnant or carry a pregnancy until birth after 12 months or more of unprotected sex. About 10% of people are infertile. This means that 1 in 10 people will not be able to conceive a child naturally. There are many causes of infertility some of them can be treated.[11] As a woman gets older, her fertility declines. After menopause a woman is no longer fertile.
↑Anderson SE, Dallal GE, Must A (April 2003). "Relative weight and race influence average age at menarche: results from two nationally representative surveys of US girls studied 25 years apart".Pediatrics.111 (4 Pt 1):844–50.doi:10.1542/peds.111.4.844.PMID12671122.{{cite journal}}: CS1 maint: multiple names: authors list (link)
