Fig 1 - uploaded by Martin Blomberg Jensen
Content may be subject to copyright.
A: Average maternal age at childbirth 1901–2014 and at first childbirth 1960–2014. B: Total fertility rate (TFR) and cumulative fertility rates for selected age groups 1901–2014.

A: Average maternal age at childbirth 1901–2014 and at first childbirth 1960–2014. B: Total fertility rate (TFR) and cumulative fertility rates for selected age groups 1901–2014.

Source publication
Article
Full-text available
Objective: Increasing age at first childbirth has been suggested to increase the risk for infertility. Our objective is to determine whether women above thirty years of age historically have been able to sustain fertility rates above replacement level. Design: A descriptive nationwide Danish study using birth registries from 1901-2014. Setting:...

Contexts in source publication

Context 1
... Denmark, the age of women at childbirth has been recorded consistently since 1900. Inter- estingly, the average age (~31 years) for women at childbirth was almost identical in 1901 and 2014 ( Fig 1A). Information on whether the child was the first born has been available from 1960. ...
Context 2
... on whether the child was the first born has been available from 1960. Fig 1A shows ...
Context 3
... fertility rate (TFR) represents the number of children born to a woman if she were to live to the end of her childbearing years. TFR of Danish women has declined during the 20th century until the 1980s, with two exceptions occurring around the First and Second World Wars when fertility rates increased (Fig 1B). The average woman had more than 4 children in the beginning of the 20th century, whereas the average was only 1.4 children per woman in 1984. ...
Context 4
... average woman had more than 4 children in the beginning of the 20th century, whereas the average was only 1.4 children per woman in 1984. In the 1990s, TFR increased to 1.8 and remained around 1.7 and 1.8 children per woman from 1994 to 2014 (Fig 1B). For 100 years ago women had on average more than twice as many children compared with women of today. ...
Context 5
... stratifying total fertility rates into age groups, it was evident that more than 50% of all children were conceived by women above the age of 30 years from 1901 to 1906 (Fig 2A-2D). Therefore, at the beginning of the century, the average woman gave birth to more than 2 children when she was older than 30 years of age, which is higher than TFR in all age groups in 2014 (TFR equal to 1.8) (Figs 1B and 2D). More than 55% of the children were born by mothers older than 30 years in 2011. ...
Context 6
... addition, women above the age of 30 years had higher fertility rates from 1901 to 1914 than women above 25 years of age have had since 1949 (Figs 1B and 2C and 2D). Age specific fertility rates Age specific fertility rates change over time and are linked to the temporal changes in TFR (Figs 1B and 2B). The rapid increases in TFR induced by the two World Wars appeared to be smaller in amplitude in the older age groups compared with younger age groups (Fig 2A and 2B). ...
Context 7
... average age at childbirth depend on number of children per mother. Women had more than twice as many children in the beginning of the 20 th century compared to the end of the century (Fig 1A and 1B). Interestingly, the average age for childbirth in the early 1900s is almost identical to the 2014 level because they had more than two children after 30 years of age. ...
Context 8
... the average age for childbirth in the early 1900s is almost identical to the 2014 level because they had more than two children after 30 years of age. Actually, the fertility rate of women over 30 years of age in 1901 exceeds the TFR of women in 2014 (Fig 1B). Moreover, it was evident that 10% of the TFR was achieved by moth- ers giving birth after the age of 40 years in the first decade of the 1900s (Fig 2C and 2D). ...

Similar publications

Article
Full-text available
Early embryonic arrest denotes premature termination of development in preimplantation embryos, which is one of the major phenotypes of recurrent assisted reproduction failure. Padi6 is proven to be a member of the subcortical maternal complex (SCMC) in mice, which is essential in oocyte maturation and embryogenesis. We and other groups previously...

Citations

... Female infertility factors contribute to approximately 50% of all infertility cases, and alone accounts for 4 approximately one-third of all infertility cases . For a woman to conceive, certain events have to take place: vaginal intercourse must take place around the time when an egg is released from the ovary, the systems that produce eggs have to be working at optimum levels and the hormones must be 5 balanced . In women, problems with fertilization may arise mainly from either structural malfunctioning of the fallopian tube or uterus or with the release of eggs. ...
Article
Full-text available
PHYSIOLOGICAL, ENDOCRINOLOGICAL AND ENVIRONMENTAL DETERMINANTS OF FEMALE INFERTILITY IN LAGOS, NIGERIA
... Fertility has always been a key issue of national concern. The decline in fertility is becoming an inevitable trend in most countries around the world, especially in developed countries (1,2). Low fertility rates are influenced by a range factor including medical infertility and lack of fertility intention (3). ...
Article
Full-text available
Background and Purpose As the global fertility rate declines, China has issued two and three-child policies in the past 10 years. Therefore, this study serves to evaluate fertility intention rates and related factors in couples intending to have a second child and third child. Methods A cross-sectional survey was conducted in mainland China from July to August 2021. Couples with one or two children were invited to participate in our study in order to collect information about more than one child fertility intention and the possibly related factors. Odds ratios (ORs) and their corresponding 95% confidence intervals (CIs) were calculated and adjusted for potential confounding factors. Results Data was collected from a total of 1,026 couples. Among couples with one child, 130 (16.2%) couples had the intention to have a second child. Additionally, only 9.4% of couples with two children desired to have third child. The study revealed large differences in socioeconomic and personal factors between the two groups. For couples with intentions for a second-child, a female age >35 years (adjusted odds ratio, aOR 1.92), a first child's age range from 3 to 6 (aOR 3.12), annual child spending as a percentage of household income >30% (aOR 2.62), and children's educational barriers (aOR 1.55) were associated with lack of intent to have a second child. Similarly, among couples with two children, parents with family financial constraints (aOR 6.18) and children's educational barriers (aOR 4.93) are more likely to have lack of intent to have a third child. Here, we report that government policies encouraging fertility (aOR 0.04) can effectly promote couples to pursue a second or third child. Conclusion Overall, couples with one or two children in Shanghai had a low intention to give birth to a second or third child. In order to increase the birth rates, it is necessary to implement policies to reduce the burden of raising children and provide relief to parent's pressure of rearing a child with increased free time.
... In the countries/regions with early industrialization (that is, starting in the 1800s), a decline in fertility rates occurred through the 1900s, although interruptions occurred during world crises, including periods of war and economic depression [6][7][8] . These trends have resulted in marked demographic changes. ...
Article
Background: Diabetes reduces semen quality and increasingly occurs during reproductive years. Diabetes medications, such as metformin, have glucose-independent effects on the male reproductive system. Associations with birth defects in offspring are unknown. Objective: To evaluate whether the risk for birth defects in offspring varies with preconceptional pharmacologic treatment of fathers with diabetes. Design: Nationwide prospective registry-based cohort study. Setting: Denmark from 1997 to 2016. Participants: All liveborn singletons from mothers without histories of diabetes or essential hypertension. Measurements: Offspring were considered exposed if their father filled 1 or more prescriptions for a diabetes drug during the development of fertilizing sperm. Sex and frequencies of major birth defects were compared across drugs, times of exposure, and siblings. Results: Of 1 116 779 offspring included, 3.3% had 1 or more major birth defects (reference). Insulin-exposed offspring (n = 5298) had the reference birth defect frequency (adjusted odds ratio [aOR], 0.98 [95% CI, 0.85 to 1.14]). Metformin-exposed offspring (n = 1451) had an elevated birth defect frequency (aOR, 1.40 [CI, 1.08 to 1.82]). For sulfonylurea-exposed offspring (n = 647), the aOR was 1.34 (CI, 0.94 to 1.92). Offspring whose fathers filled a metformin prescription in the year before (n = 1751) or after (n = 2484) sperm development had reference birth defect frequencies (aORs, 0.88 [CI, 0.59 to 1.31] and 0.92 [CI, 0.68 to 1.26], respectively), as did unexposed siblings of exposed offspring (3.2%; exposed vs. unexposed OR, 1.54 [CI, 0.94 to 2.53]). Among metformin-exposed offspring, genital birth defects, all in boys, were more common (aOR, 3.39 [CI, 1.82 to 6.30]), while the proportion of male offspring was lower (49.4% vs. 51.4%, P = 0.073). Limitation: Information on underlying disease status was limited. Conclusion: Preconception paternal metformin treatment is associated with major birth defects, particularly genital birth defects in boys. Further research should replicate these findings and clarify the causation. Primary funding source: National Institutes of Health.
... Our results suggest a possible protective effect of pregnancies on MS risk. With an increase of the maternal age at first childbirth 33,34 and decreasing birth rates 35 in the last decades, a protective effect of pregnancies on disease risk could, at least in part, explain the increasing gender gap in MS incidence. We also observed previously not reported associations of gynecological disorders unrelated to pregnancies with lower MS risk. ...
Article
Full-text available
Background: Pregnancies have an impact on the disease course of multiple sclerosis (MS), but their relationship with MS risk is yet unclear. Objective: To determine the relationships of pregnancies and gynecological diagnoses with MS risk. Methods: In this retrospective case-control study, we assessed differences in gynecological International Classification of Diseases, 10th Revision (ICD-10) code recording rates between women with MS (n = 5720), Crohn's disease (n = 6280), or psoriasis (n = 40,555) and women without these autoimmune diseases (n = 26,729) in the 5 years before diagnosis. Results: Twenty-eight ICD-10 codes were recorded less frequently for women with MS as compared to women without autoimmune disease, 18 of which are pregnancy-related. After adjustment for pregnancies, all codes unrelated to pregnancies were still negatively associated with MS. In a sensitivity analysis excluding women with evidence for possible demyelinating events before diagnosis, all associations were more pronounced. In comparison to women with psoriasis, most associations could be confirmed; that was not true in comparison to women with Crohn's disease. Conclusion: Our findings provide evidence for a possible protective effect of pregnancies on MS risk likely independent of or in addition to a previously suggested reversed causality. The negative associations of gynecological disorders with disease risk need further investigation. The associations might be shared by different autoimmune diseases.
... There are three main latent variables (SD, ME, HSR) expected to impact LE. SD consists of 5 observable variables: the primary and secondary school enrollment as the percentage of primary/secondary school enrollment annually [31,32], IMR as the rate of infant mortality per 1000 live births annually [33], fertility rate as the total birth per woman annually [34], and female adult mortality rate as the ratio of adult mortality of female population annually [35]. In the ME, observable variables include the GDP per capita as the gross domestic product per number of population in current US$ annually [11][12][13][14][15], the dependency ratio as the percentage of the working-age population annually [36], and capital investment in billion US$ annually [37]. ...
Article
Introduction: the factors determining life expectancy (LE) are crucial for policymakers to study in implementing an effective and accurate intervention in society. In Oman, the available data over the past four decades were not extracted to develop a statistical model to understand how the sociodemographic (SD), macroeconomic (ME), and health-status and resources (HSR) factors affecting LE. The study was aimed at creating a representative model to explain the factors affecting LE in Oman and examine the direct and indirect effects of SD, ME, and HSR in LE in Oman. Methods: the research was a retrospective, ecological, time-series study design to collect the annual published data on SD, ME, and HSR in Oman from all available resources from 1978 to 2018. The data were then analyzed with structural equation modeling (SEM) method using IBM® SPSS® Amos 24 for the study of their impacts in LE. Results: in Oman, using SEM, the SD, ME, and HSR significantly and directly affected LE by the estimate of -0.92 (p < 0.001), -0.15 (p < 0.001), and 0.23 (p < 0.001) respectively. Conclusion: the study was the first attempt to analyze all the different aspects of LE comprehensively in Oman. In the case of Oman, the health resource is an important factor that need to be addressed to increase or to maintain the current LE. Hence, during social hardship or economic recession, health-related support by the government should be continued or even improved because of its positive effect on LE.
... In the countries/regions with early industrialization (that is, starting in the 1800s), a decline in fertility rates occurred through the 1900s, although interruptions occurred during world crises, including periods of war and economic depression [6][7][8] . These trends have resulted in marked demographic changes. ...
Article
A severe decline in child births has occurred over the past half century, which will lead to considerable population declines, particularly in industrialized regions. A crucial question is whether this decline can be explained by economic and behavioural factors alone, as suggested by demographic reports, or to what degree biological factors are also involved. Here, we discuss data suggesting that human reproductive health is deteriorating in industrialized regions. Widespread infertility and the need for assisted reproduction due to poor semen quality and/or oocyte failure are now major health issues. Other indicators of declining reproductive health include a worldwide increasing incidence in testicular cancer among young men and alterations in twinning frequency. There is also evidence of a parallel decline in rates of legal abortions, revealing a deterioration in total conception rates. Subtle alterations in fertility rates were already visible around 1900, and most industrialized regions now have rates below levels required to sustain their populations. We hypothesize that these reproductive health problems are partially linked to increasing human exposures to chemicals originating directly or indirectly from fossil fuels. If the current infertility epidemic is indeed linked to such exposures, decisive regulatory action underpinned by unconventional, interdisciplinary research collaborations will be needed to reverse the trends.
... Historical data have provided important insights on number of children per woman in societies without access to high-quality healthcare and birth control. 11 However, these studies are limited as regards adverse early pregnancy outcomes such as pregnancy losses and ectopic pregnancies. 12 The prerequisite for obtaining these kinds of data is access to large, unselected cohorts of women followed throughout their fertile years with accurate and reliable data on all pregnancy outcomes. ...
Article
Full-text available
Introduction: The impact of early pregnancy complications on completed family size is unknown. Here, we hypothesize that early pregnancy complications and adverse outcomes may influence family size. Material and methods: In this nationwide, registry-based study we included all 458 475 women born 1957-1972 who lived in Denmark from age 20-45 years with at least one registered pregnancy. The main outcome of the study was number of children per woman by age 45, estimated using a Generalized Linear Mixed Model. Exposures were: (a) total number of pregnancy losses experienced (0, 1, 2, ≥3); (b) highest number of consecutive pregnancy losses (0, 1, 2, ≥3); (c) sex of firstborn child; (d) outcome of first pregnancy (live birth, stillbirth, pregnancy loss, ectopic pregnancy, or molar pregnancy). Results: Number of live births was negatively influenced by maternal age and adverse first pregnancy outcomes, especially ectopic pregnancies. A 30-year-old woman with a first ectopic pregnancy was expected to have 1.16 children (95% CI 1.11-1.22) compared with 1.95 children (95% CI 1.86-2.03) with a first live birth. Three or more consecutive losses also decreased number of live births significantly: 1.57 (95% CI 1.50-1.65) compared with 1.92 (95% CI 1.84-2.0) with only live births. The total number of pregnancy losses had no effect before the age of 35 years. Sex of firstborn had no effect. Conclusions: Previous pregnancy history has a significant effect on number of children per woman, which is important at both individual and societal levels. Pathophysiological research of adverse pregnancy outcomes should be an urgent priority as the causes remain poorly understood.
... As proposed by Jensen et al, older women have been found to be able to sustain fertility rates above the replacement so that having a child between the age of 30 and 40 years is in biological limit. 20 However, high fertility rates of women above 30 years of age were due to giving birth to several children which occurs rarely nowadays. This change in fertility pattern emanates from the decision of having lower number of children due to cultural, economic and social circumstances or results from childbearing postponement. ...
Article
Full-text available
Objectives We described the trend of fertility rates, age-specific fertility rates and associated factors in Finland over a 30-year period. Design A descriptive population-based register study. Setting Fertility data, including age at first birth, childlessness and educational levels were gathered from the Finnish Medical Birth Register and Statistics Finland. Participants All 1 792 792 live births from 1987 to 2016 in Finland. Main outcome measures Completed fertility rate, total fertility rate and age-specific fertility rate. Results The total fertility rate of Finnish women fluctuated substantially from 1987 to 2016. Since 2010, the total fertility rate has gradually declined and reached the lowest during the study period in 2016: 1.57 children per woman. The mean maternal age at first birth rose by 2.5 years from 26.5 years in 1987 to 29 years in 2016. The proportion of childless women at the age of 50 years increased from 13.6% in 1989 to 19.6% in 2016. By considering the impact of postponement and childlessness, the effect on total fertility rates was between −0.01 and −0.12 points. Since 1987, the distribution of birth has declined for women under the age of 29 and increased for women aged 30 or more. However, start of childbearing after the age of 30 years was related to the completed fertility rate of less than two children per woman. The difference in completed fertility rate across educational groups was small. Conclusions Postponement of first births was followed by decline in completed fertility rate. Increasing rate of childlessness, besides the mean age at first birth, was an important determinant for declined fertility rates, but the relation between women’s educational levels and the completed fertility rate was relatively weak.
... It is a fact that fertility rate has declined in almost every part of the world, not only in developing countries [1] but also in Denmark [2]. In a news mentioned that the diagnosis causes infertility is more due to men than women. ...
Article
Full-text available
Fertility is a crucial issue for married couples for ages and a significant clinical problem today. Not only do women have an undue burden of responsibility in fertility regulation but also men. There are some major causes and risk factors for male infertility i.e., environmental factors, life style factors etc. In this paper, we will analyse the infertility using two algorithms, decision tree and k-nearest neighbours. We will do experiments using different splits of training data and different filters. The purpose is to determine which algorithm is more accurate between 2 algorithms either using filter or not. The result shows DT has better performance in accuracy when using dataset without filter and when using randomize filter while k-NN has better performance when using resample filter.
... Reproductive life span from the onset of puberty, age-specific fertility rates, and twinning frequency all contribute to fertility. [1][2][3][4] Other factors influencing female fertility include developmental programming, common diseases such as polycystic ovarian syndrome (PCOS) and endometriosis, and the cumulative effects of environmental exposures and lifestyle. [5][6][7][8] There is substantial genetic variation for common traits associated with reproductive lifespan and common diseases influencing female fertility. ...
Article
Full-text available
Variation in reproductive lifespan and female fertility have implications for health, population size and ageing. Fertility declines well before general signs of menopause and is also adversely affected by common reproductive diseases, including polycystic ovarian syndrome (PCOS) and endometriosis. Understanding the factors that regulate the timing of puberty and menopause, and the relationships with fertility are important for individuals and for policy. Substantial genetic variation exists for common traits associated with reproductive lifespan and for common diseases influencing female fertility. Genetic studies have identified mutations in genes contributing to disorders of reproduction, and in the last ten years, genome-wide association studies (GWAS) have transformed our understanding of common genetic contributions to these complex traits and diseases. These studies have made great progress towards understanding the genetic factors contributing to variation in traits and diseases influencing female fertility. The data emerging from GWAS demonstrate the utility of genetics to explain epidemiological observations, revealing shared biological pathways linking puberty timing, fertility, reproductive ageing and health outcomes. Many variants implicate DNA damage/repair genes in variation in the age at menopause with implications for follicle health and ageing. In addition to the discovery of individual genes and pathways, the increasingly powerful studies on common genetic risk factors help interpret the underlying relationships and direction of causation in the regulation of reproductive lifespan, fertility and related traits.