Fertility
In demographic contexts, fertility refers to the actual production of offspring, rather than the physical capability to reproduce, which is termed fecundity.
[4] In general, infertility or subfertility[5] in humans is defined as not being able to conceive a child after one year (or longer) of unprotected sex.
In demographic contexts, fertility refers to the actual production of offspring, rather than the physical capability to produce which is termed fecundity.
[9] Factors generally associated with increased fertility include religiosity,[10] intention to have children,[11] and maternal support.
[12] Factors generally associated with decreased fertility include wealth, education,[13][14] female labor participation,[15] urban residence,[16] cost of housing,[17][18] intelligence, increased female age and (to a lesser degree) increased male age.
Men are fertile continuously, but their sperm quality is affected by their health, frequency of ejaculation, and environmental factors.
When estrogen levels peak, it spurs a surge of luteinizing hormone (LH) which completes maturation and enables the ovum to break through the ovary wall.
During the luteal phase following ovulation LH and FSH cause the post-ovulation ovary to develop into the corpus luteum which produces progesterone.
[36][37] During menopause, hormonal production by the ovaries is reduced, eventually causing a permanent cessation of the creation of the uterine lining (period).
[40] According to an opinion by the Practice Committee of the American Society for Reproductive Medicine, specific coital timing or position, and resting supine after intercourse have no significant impact on fertility.
[43] Sperm count declines with age, with men aged 50–80 years producing sperm at an average rate of 75% compared with men aged 20–50 years and larger differences exist in the number of seminiferous tubules in the testes containing mature sperm:[43] Decline in male fertility is influenced by many factors, including lifestyle, environment and psychological factors.
[45] Some research suggests increased risks for health problems for children of older fathers, but no clear association has been proven.
[48][49][50][51][52] Australian researchers have found evidence to suggest obesity may cause subtle damage to sperm and prevent a healthy pregnancy.
They are a step closer to legalizing fertility treatments for all women regardless of sexual orientation or marital status.
[58] A variety of explanations have been proposed, ranging from investment in education[59] to birth control, abortion, a decline in the marriage rate, divorce, female participation in the labor force, and the 1997 Asian financial crisis.
[60] After being legal from the 1960s to the 1980s, abortion was again made illegal in South Korea in the early 2000s in an attempt to reverse the declining fertility rate.
