Advanced maternal age
Advanced maternal age, in a broad sense, is the instance of a woman being of an older age at a stage of reproduction, although there are various definitions of specific age and stage of reproduction.[1] The variability in definitions is in part explained by the effects of increasing age occurring as a continuum rather than as a threshold effect.[1]
Average age at first childbirth has been increasing, especially in OECD countries, among which the highest average age is 32.6 years (South Korea) followed by 32.1 years (Ireland and Spain).[2] In a number of European countries (Spain), the mean age of women at first childbirth has crossed the 30 year threshold.[3] This process is not restricted to Europe. Asia, Japan and the United States are all seeing average age at first birth on the rise, and increasingly the process is spreading to countries in the
Advanced maternal age is associated with adverse reproductive effects including increased risk of
History
Having children later was not exceptional in the past, when families were larger and women often continued bearing children until the end of their reproductive age. What is so radical about this recent transformation is that it is the age at which women give birth to their first child, which is becoming comparatively high, leaving an ever more constricted window of biological opportunity for second and subsequent children, should they be desired. Unsurprisingly, high first-birth ages and high rates of birth postponement are associated with the arrival of low, and lowest-low fertility.[9]
This association has now become especially clear, since the postponement of first births in a number of countries has now continued unabated for more than three decades and has become one of the most prominent characteristics of fertility patterns in developed societies. A variety of authors (in particular, Lesthaeghe) have argued that fertility postponement constitutes the "hallmark" of what has become known as the “second demographic transition”. [citation needed]
Others have proposed that the postponement process itself constitutes a separate "third transition".[10] On this latter view, modern developed societies exhibit a kind of dual fertility pattern, with the majority of
Examples
In the USA, the average age at which women bore their first child advanced from 21.4 years old in 1970[11] to 26.9 in 2018.[4]
The German Federal Institute for Population Research claimed in 2015 the percentage for women with an age of at least 35 giving birth to a child was 25.9%. This figure rose from 7.6% in 1981.[12]
Possible factors that influence childbearing age
There are many factors that may influence childbearing age in women, although they are mostly correlations without certain causations. For instance, older maternal age at first childbirth is associated with higher educational attainment and income.[13]
Two studies show that generous parental leave allowances in Britain encourage young motherhood and that parental-leave allowance reduces postponement in Sweden.[14]
Effects
Decreased fertility
A woman's fertility peaks lasts during the twenties and first half of thirties, after which it starts to decline, with advanced maternal age causing an increased risk of female infertility.
According to Henri Leridon, PhD, an epidemiologist with the French Institute of Health and Medical Research, of women trying to get pregnant, without using fertility drugs or in vitro fertilization:[5]
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] |
Risk of birth defects
A woman's risk of having a baby with
- Risk of having a baby with Down syndrome
Age Risk 20 1/ 2 000
24
1/ 1 300
25
1/ 1 200
29
1/ 950
30
1/ 900
Age Risk 34 1/ 450
35
1/ 350
39
1/150
40
1/ 100
Age Risk 44 1/ 40
45
1/ 30
49
1/ 10
Other effects
Advanced maternal age is associated with adverse outcomes in the
The risk of the mother dying before the child becomes an adult increases by more advanced maternal age, such as can be demonstrated by the following data from France in 2007:[18]
Maternal age at childbirth (years) | 20 | 25 | 30 | 35 | 40 | 45 |
---|---|---|---|---|---|---|
Risk of mother not surviving to the child's 18th birthday (in %)[18]
|
0.6 % | 1.0 % | 1.6 % | 2.6 % | 3.8 % | 5.5 % |
The above table is not to be confused with
Advanced maternal age continues to be associated with a range of adverse pregnancy outcomes including low birth weight, pre-term birth, stillbirth, unexplained fetal death, and increased rates of Caesarean section. However, over time, improvements in (and improvements in access to) medical services and social resources have decreased the negative association between older maternal age and low birth weight.[19]
On the other hand, advanced maternal age is associated with a more stable family environment, higher socio-economic position, higher income and better living conditions, as well as better parenting practices[18] (including better disciplinary methods[20]). A qualitative study on couples in the United States who used in-vitro fertilization to conceive their first child when the woman was aged 40 or older at the time of delivery found that 72% of the women and 57% of the men believed that they had enhanced emotional preparedness for parenting which benefitted both their children and themselves.[21] In quantitative studies, mother’s older age at first birth has been associated with increases in children’s psychiatric health,[22] language skills,[22] cognitive ability,[23] and fewer social and emotional difficulties.[20] Further, a study in the United Kingdom showed that older maternal age at first birth was associated with fewer hospital admissions and fewer unintentional injuries for children up to age 5 and a greater likelihood of having had all of their immunizations by 9 months of age – all outcomes used as indicators of child wellbeing in reports from the World Health Organisation.[24]
Changes in interpregnancy interval
Kalberer et al.[25] have shown that despite the older maternal age at birth of the first child, the time span between the birth of the first and the second child (the interpregnancy interval) decreased over the last decades. If purely biological factors were at work, it could be argued that interpregnancy interval should have increased, as fertility declines with age, which would make it harder for the woman to get a second child after postponed birth of the first one. This not being the case shows that sociologic factors (see above) prime over biological factors in determining interpregnancy interval.
With technology developments cases of
Ovarian aging
As women age, they experience a decline in reproductive performance leading to
Titus et al.
Women with an inherited mutation in the DNA repair gene BRCA1 undergo menopause prematurely,[31] suggesting that naturally occurring DNA damages in oocytes are repaired less efficiently in these women, and this inefficiency leads to early reproductive failure. Genomic data from about 70,000 women were analyzed to identify protein-coding variation associated with age at natural menopause.[32] Pathway analyses identified a major association with DNA damage response genes, particularly those expressed during meiosis and including a common coding variant in the BRCA1 gene.
See also
- Age and female fertility
- Childlessness
- Fertility factor (demography)
- List of countries by age at first marriage
- Pregnancy over age 50
- Teenage pregnancy
References
- ^ a b Fretts, Ruth C. (3 December 2012). "Effect of advanced age on fertility and pregnancy in women". UpToDate. Wilkins-Haug, Louise (Section Editor); Barss, Vanessa A. (Deputy Editor). Archived from the original on 19 June 2016.
- ^ "¿A qué edad tienen las madres su primer hijo?" [At what age do mothers have their first child?]. El Orden Mundial (elordenmundial.com) (in Spanish). 12 August 2020.
- ^ Mean age of mothers at first childbirth (PDF). oecd.org (Report). Paris, FR: Organisation for Economic Co-operation and Development. SF2.3. Archived from the original (PDF) on 22 December 2014. Retrieved 27 May 2014.
- ^ a b
Births and natality. cdc.org (Report). U.S. Centers for Disease Control. Archivedfrom the original on 12 November 2019. Retrieved 8 September 2017.
- ^ PMID 15205397.
- ^ a b
Morris, J.K.; Mutton, D.E.; Alberman, E. (March 2002). "Revised estimates of the maternal age specific live birth prevalence of Down's syndrome". Journal of Medical Screening. 9 (1): 2–6. PMID 11943789.
- ^
Tournaye, Herman (June 2009). "Male reproductive ageing". In Bewley, Susan; Ledger, William; Nikolaou, Dimitrios (eds.). Reproductive Ageing. Cambridge University Press. pp. 95–104. ISBN 978-1-906985-13-4. Archivedfrom the original on 4 November 2020. Retrieved 24 October 2020.
- ^
Kidd, Sharon A.; Eskenazi, Brenda; Wyrobek, Andrew J. (February 2001). "Effects of male age on semen quality and fertility: A review of the literature". Fertility and Sterility. 75 (2): 237–248. PMID 11172821.
- ^ "U.S. women more likely to have children than a decade ago". Pew Research Center’s Social & Demographic Trends Project. 18 January 2018. Retrieved 29 October 2020.
- ^ Kohler, Hans-Peter; Billari, Francesco C.; Ortega, Jose Antonio (December 2002). "The emergence of lowest-low fertility in Europe during the 1990s". Population and Development Review. 28 (4): 641–680. .
- Centers for Disease Control. Archived(PDF) from the original on 25 November 2017. Retrieved 26 August 2013.
- ^ "Jedes vierte Neugeborene hat eine Mutter über 34 Jahre" [Every fourth newborn has a mother aged over 34 years] (PDF). bib-demografie.de (Press release) (in German). Wiesbaden, DE: Bundesinstitut für Bevölkerungsforschung [Federal Institute for Population Research]. Archived from the original (PDF) on 22 December 2017. Retrieved 20 December 2017.
- PMID 27854529.
- PMID 23440941.
- PMID 12099629.
- ^ "About Down syndrome". ndss.org. National Syndrome Down Society.
- PMID 23103636.
- ^ PMID 21989171.
- S2CID 2977607.
- ^ (PDF) from the original on 19 July 2018. Retrieved 19 July 2019.
- PMID 22333985.
- ^ (PDF) from the original on 20 July 2018. Retrieved 19 July 2019.
- PMID 28177512.
- PMID 22915663.
- (PDF) from the original on 19 July 2018. Retrieved 19 July 2019.
- ^ "Woman, 61, pregnant". The Sydney Morning Herald. 27 September 2011. Archived from the original on 27 April 2016. Retrieved 8 February 2013.
- ^ Moreno, Carolina (26 October 2012). "Look: 61 year-old woman gives birth to twins". HuffPost (huffingtonpost.com). Archived from the original on 3 August 2016. Retrieved 13 October 2017.
- ^ "Menopause". medlineplus.gov. Archived from the original on 16 October 2020. Retrieved 29 October 2020.
- PMID 18192670.
- ^ PMID 23408054.
- S2CID 19572648.
- PMID 26414677.
Sources
- Lorentzon, M.; et al. (2012). "Advancing maternal age is associated with lower bone mineral density in young adult male offspring". Osteoporosis International. 23 (2): 475–482. PMID 21350896.
- Nilsen, A.B.; et al. (2012). "Characteristics of women who are pregnant with their first baby at an advanced age". Acta Obstetricia et Gynecologica Scandinavica. 91 (3): 353–362. S2CID 38149716.
- Khashan, Ali S.; et al. (2013). "Advanced maternal age and adverse pregnancy outcome: Evidence from a large contemporary cohort". PLOS ONE. 8 (2): 1–9. PMID 23437176.
- Jabcosson, B.; Ladfords, L.; Milsom, I. (2004). "Advanced maternal age and adverse perinatal outcome". S2CID 8652247.
Further reading
- Charlemagne (9 February 2006). "The fertility bust". Europe. The Economist.
- Gavrilov, L.A.; Gavrilova, N.S. (1997). "Parental age at conception and offspring longevity". .
- Gavrilov, L.A.; Gavrilova, N.S. (2000). "Human longevity and parental age at conception". In Robine, J.-M.; Kirkwood, T.B.L.; Allard, M. (eds.). Sex and Longevity: Sexuality, gender, reproduction, parenthood. Berlin / Heidelberg, DE: Springer-Verlag. pp. 7–31. ISBN 3-540-67740-2.
- Hofmeister, Heather; Mills, Melinda; Blossfeld, Hans-Peter (2006). "Globalization, Uncertainty and Women's, Mid-Career Life Courses: A theoretical framework". In Blossfeld, Hans-Peter; Hofmeister, Heather (eds.). Globalization, Uncertainty, and Women's Careers : An international comparison. Cheltenham. pp. 3–31. ISBN 1-84542-664-9.)
{{cite book}}
: CS1 maint: location missing publisher (link - Kohler, Hans-Peter; Billari, Francesco C.; Ortega, José Antonio (2006). "Low fertility in Europe: Causes, implications and policy options". In Harris, Fred R. (ed.). The Baby Bust: Who will do the work? Who will pay the taxes?. Rowman & Littlefield. pp. 48–109. ISBN 978-0-7425-3855-9.
- Lesthaeghe, R.; Neels, K. (2002). "From the first to the second demographic transition: An interpretation of the spatial continuity of demographic innovation in France, Belgium and Switzerland". European Journal of Population. 18 (4): 325–360. S2CID 878879.
- Sobotka, Tomás (25 November 2004). Postponement of childbearing and low fertility in Europe. Faculty of Spatial Sciences (Ph.D. thesis). Groningen, DE: University of Groningen. ISBN 9036191025.
External links
- Sobotka, Tomás. Postponement of childbearing and low fertility in Europe (Power Point presentation).
- "InterNational Council on Infertility Information Dissemination". inciid.org.