Age of elderly mother , in a broad sense, is an example of an older woman at the reproductive stage, although there are definitions of age and certain reproductive phases. The variability in the definition is partially explained by the effect of age increase that occurs as a continuum rather than as a threshold effect.
In Western Europe, North and South, first mothers aged 26 to 29, up from 23 to 25 in the early 1970s. In some European countries (Spain), the average age of women in the first delivery has crossed the threshold of 30 years.
This process is not limited to Europe. Asia, Japan and the United States all see the average age at the first birth as it increases, and the process is spreading to developing countries like China, Turkey and Iran. In the US, the average age of first delivery is 26 in 2013.
Motherhood is associated with adverse reproductive effects such as an increased risk of infertility, and that children have chromosomal abnormalities. The corresponding father age effect is less pronounced.
In the present generation, it is more common to have children at older ages. Several factors can affect a parent's decision when having their first baby. These factors include education, social status and economics.
Video Advanced maternal age
History
Having children in later life is not remarkable in the past, when families were bigger and women often continued to deliver children until the end of their reproductive age. What is so radical about recent transformations is that the age at which women give birth to their first child becomes relatively high, leaving the window of increasingly limited biological opportunities for the second and subsequent children, if they are desired. Not surprisingly, high first birth age and high birth delay rates are associated with low arrivals, and lowest lowest fertility.
This association is now very clear, since the first birth delay in some countries has now continued for more than three decades, and has become one of the most prominent characteristics of fertility patterns in advanced societies. Various authors (especially Lesthaeghe) argue that fertility delays are a 'feature' of what has been known as the second demographic transition.
Others suggest that the process of delay itself is a separate 'third transition'. In this last view, the emerging modern society shows a kind of double fertility pattern, with the majority of births concentrated either among very young or old mothers. This is sometimes known as the 'rectangularization' of fertility patterns.
Maps Advanced maternal age
Example
In the United States, the average age at which women give birth to their first child increased from 21.4 years in 1970, to 25 years in 2006.
The German Federal Institute for Population Research claims in 2015 the percentage for women with age at least 35 childbearing is 25.9%. This figure rose from 7.6% in 1981.
Possible factors affecting childbearing age
There are many factors that can affect the fertile age in women, although they are largely correlated with no particular cause.
Two studies have shown that a large parental leave allowance in Britain encourages young mothers and the parental leave allowances reduce delays in Sweden.
Effects
Decrease fertility
The peak fertility of a woman lasts during the twenties and the first half of the thirties, after which it begins to decline, with advanced maternal age causing an increased risk of female infertility.
According to Henri Leridon, PhD, an epidemiologist from the French Institute of Health and Medical Research, women who are trying to conceive, without the use of fertility drugs or in vitro fertilization:
- At the age of 30
- 75% will have a conception that ends with a live birth within a year
- 91% will have a conception that ends with a live birth in four years.
- At age 35
- 66% will have a conception that ends with a live birth within a year
- 84% will have a conception that ends with a live birth in four years.
- At the age of 40
- 44% will have a conception that ends with a live birth within a year
- 64% will have a conception that ends with a live birth in four years.
The risk of birth defects
The risk of a woman having a baby with chromosomal abnormalities increases with age. Down syndrome is the most common birth defect of chromosomes, and a woman's risk of having a baby with Down's syndrome is:
- At the age of 20, 1 in 1,441
- At the age of 25, 1 in 1,383
- At age 30, 1 in 959
- At age 35, 1 in 338
- At age 40, 1 in 84 years
- At age 45, 1 in 32
- At age 50, 1 in 44 years
Other effects
Motherhood is associated with adverse outcomes in the perinatal period, which may be caused by adverse effects on decidual and placental development.
The risk of mothers who die before the child matures increases as the mother's age is more advanced, as can be demonstrated by the following data from France in 2007:
The age of the elderly mother continues to be associated with a variety of adverse pregnancy outcomes including low birth weight, premature birth, stillbirth, unexplained fetal death, and increased caesarean section rate.
On the other hand, advanced maternal age is associated with a more stable family environment, higher socioeconomic position, higher income and better living conditions, and better parenting practices, but it is more or less uncertain whether this entity is> effect of the elderly mother's age, is contributor for the age of the advanced mother, or the general effect of certain circumstances such as personality type.
Interpregnancy interval change
Kalberer et al. has shown that although the age of the older mother at the birth of the first child, the time span between the birth of the first and second child (= interval interpregnancy) has decreased over the last few decades. If pure biological factors are at work, it can be said that the interval of interpregnancy should increase, as fertility declines with age, which will make it more difficult for women to get a second child after the delayed birth from the first. This is not the case indicating that the sociological factors (see above) prime over the biological factors in determining the interpregnancy interval.
With the development of post-menopausal pregnancy technology cases have occurred, and there are some known cases of older women carrying a term pregnancy, usually by in vitro fertilization of egg donors. A 61-year-old Brazilian woman with egg donor implantation is expected to give birth to twins in October 2011..
Ovarian aging
As women age, they experience a decline in reproductive performance that leads to menopause. This decrease is associated with a decrease in the number of ovarian follicles. Although about 1 million oocytes are present at birth in the human ovaries, only about 500 (about 0.05%) of this ovulation, and the rest are not (ovary follicle atresia). The decrease in ovarian reserves appears to occur at an ever increasing rate with increasing age, and leads to near-ending reserves at around 51 years of age. Because ovarian and fertility reserves decline with age, there is also a parallel increase in failure of pregnancy and meiosis. error produces an abnormal chromosomal conception.
Titus et al. has proposed an explanation for the decrease in ovarian reserves by age. They show that when women age, double strands rupture accumulate in DNA from their primordial follicles. The primordial follicle is an immature primary oocyte surrounded by a layer of granulosa cells. The enzyme system is present in oocytes that usually accurately repair the DNA damage of multiple strands. This repair system is referred to as an improvement in homologous recombination, and is especially active during meiosis. Meiosis is a common process in which germ cells are formed in eukaryotes, and it appears to be an adaptation to efficiently eliminate damage to germ line DNA with improved homologous recombination (see Origin and meiotic function as well). The primary human oocyte is present at the intermediate stage of meiosis, ie prophase I (see Oogenesis). Titus et al. also shows that the expression of four key DNA repair genes required for homologous recombination repair ( BRCA1 , MRE11 , Rad51 and ATM ) decreased oocyte with age. This age-related decline in the ability to repair double damage can lead to the accumulation of this damage, which then contributes to a decrease in ovarian reserves.
Source of the article : Wikipedia
0 Comments