Change in the perceived reproductive age window and delayed fertility in Europe.

While extensive literature documents the massive fertility delay of recent decades, knowledge about whether and how attitudes towards the timing of births have changed in Europe remains limited. Using data from two rounds of the European Social Survey, we investigate these changes and their association with macro-level fertility indicators in 21 countries. Between 2006-07 and 2018-19, societal consensus regarding the existence of optimal childbearing ages remained strong and became more in favour of later parenthood. Decomposition analyses show that these shifts were driven only partially by changes in population composition, supporting the idea that a general attitudinal change in favour of later childbearing is underway. We also find a trend towards gender convergence in upper age limits driven by the increasing social recognition of an age deadline for men's childbearing. Although shifts in perceived reproductive age windows occurred during periods of birth postponement, they corresponded only loosely to country-level changes in fertility.

Parental sociodemographics of medically assisted reproduction births in the United States: a dyadic population-level study.

Objective: To study how men's and couples' sociodemographic characteristics predict the probability of having a birth conceived using medically assisted reproduction (MAR) in the United States. Design: Population-based study. Setting: Not applicable. Patients: Men and women in the National Vital Statistics Birth certificate data from 2009 to 2019. Intervention: None. Main Outcome Measures: Proportion of MAR births out of total births by parental sociodemographic categories and probability of having a MAR birth. Results: Between 2009 and 2019, the overall prevalence of MAR births among men was 1.81%. Fathers of children conceived using MAR tended to be older, higher educated, and white compared with fathers of naturally conceived children. During the period of 2009-2019, these sociodemographic profiles remained largely unchanged. Controlling for maternal age and birth order only partially reduced disparities by education and race. In 2019, highly educated fathers were 2.04 percentage points (95% confidence interval, 1.97-2.12) more likely to have a MAR-conceived birth than fathers with a low educational level, and black fathers were associated with a reduction in the probability of having an MAR-conceived child by - 1.07 percentage points (95% confidence interval, -1.11 to -1.04) compared with white fathers. The dyadic analysis using parents' education and race interactions revealed that partnering with someone of a higher educational level increases the likelihood of having a MAR birth, beyond what would be observed by considering only individual-level characteristics. Conclusions: To comprehend the environment in which MAR-conceived children are born and raised, performing dyadic analyses that examine the characteristics of both partners is essential. The findings underscore the enduring presence of substantial social disparities in MAR use in the United States, with MAR-conceived children raised in environments of relative advantage, which may impact their future health and development.

Childbirth timing and completed family size by the mode of conception-the role of medically assisted reproduction: a population-based cohort study in Australia.

Background: With declining total fertility rates to below replacement levels amongst all high-, middle- and low-income countries, coupled with increasing use of medically assisted reproduction (MAR) treatments globally, we describe the impact of these treatments on completed family size and childbearing timing in a country with unlimited publicly funded access to MAR. Methods: We utilised a unique longitudinal propensity score-weighted population-based birth cohort that included nulliparous mothers who gave birth after all major forms of MAR treatments (assisted reproductive technologies [ART], ovulation induction [OI], and intrauterine insemination [IUI]) and after natural conception (reference category) in Australia, 2003-2017. We followed first-time mothers over their reproductive lifespan (15-50 years). The primary outcome was completed family size (i.e., the mean cumulative number of children per mother of our cohort) and the fertility gap (i.e., adjusted difference in completed family size between MAR conceptions and the reference). Findings: Our cohort includes 481,866 first-time mothers, mean follow-up of 13.8 years. ART mothers (n = 25,296) were six years older (mean age: 34.6 years) than mothers who conceived naturally (28.7 years (reference)) while OI/IUI mothers were only 2.2 years older (31.0 years) than the reference. ART mothers had up to 27% smaller completed family size (2.54 children) compared to OI/IUI mothers (2.98 children) and natural conception mothers (3.23 children). ART mothers who resided in the lower socioeconomic areas were less likely to reach a similar family size to the natural conception mothers (fertility gap of 0.83 fewer children per ART mother compared to natural conception mothers) than ART mothers who resided in the higher socioeconomic areas (0.43 fewer children). Interpretation: Greater awareness of the limitations of MAR treatment to resolve childlessness and achieve desired family size is needed. Furthermore, with policymakers increasingly turning to MAR treatment as a tool to reverse declining fertility rates, their potential impact should not be overestimated. Funding: Australian National Health and Medical Research Council.

The contribution of survival to changes in the net reproduction rate.

The net reproduction rate (NRR) is an alternative fertility measure to the more common total fertility rate (TFR) and accounts for the mortality context of the population studied. This study is the first to compare NRR trends in high- and low-income countries and to decompose NRR changes over time into fertility and survival components. The results show that changes in the NRR have been driven mostly by changes in fertility. Yet improvements in survival have also played an important role in explaining changes in the NRR over the last century and represent a substantial component of change in some low-income countries today. Furthermore, the decomposition of the survival component by age indicates that the survival effect on population reproduction is concentrated mostly in infancy, although the HIV/AIDS epidemic altered this age profile in some populations. The findings highlight the importance of mortality's effect on reproduction in specific periods and contexts.

Projecting the Contribution of Assisted Reproductive Technology to Completed Cohort Fertility.

Assisted reproductive technology (ART) is increasingly influencing the fertility trends of high-income countries characterized by a pattern of delayed childbearing. However, research on the impact of ART on completed fertility is limited and the extent to which delayed births are realized later in life through ART is not well understood. This study uses data from Australian fertility clinics and national birth registries to project the contribution of ART for cohorts of women that have not yet completed their reproductive life and estimate the role played by ART in the fertility 'recuperation' process. Assuming that the increasing trends in ART success rates and treatment rates continue, the projection shows that the contribution of ART-conceived births to completed fertility will increase from 2.1% among women born in 1968 to 5.7% among women born in 1986. ART is projected to substantially affect the extent to which childbearing delay will be compensated at older ages, suggesting that its availability may become an important factor in helping women to achieve their reproductive plans later in life. Supplementary Information: The online version contains supplementary material available at 10.1007/s11113-023-09765-3.

Cross-sectional average length of life by parity: Country comparisons.

This study aims to present an alternative measure of fertility-cross-sectional average length of life by parity (CALP)-which: (1) is a period fertility indicator using all available cohort information; (2) captures the dynamics of parity transitions; and (3) links information on fertility quantum and timing together as part of a single phenomenon. Using data from the Human Fertility Database, we calculate CALP for 12 countries in the Global North. Our results show that women spend the longest time at parity zero on average, and in countries where women spend comparatively longer time at parity zero, they spend fewer years at parities one and two. The analysis is extended by decomposing the differences in CALPs between Sweden and the United States, revealing age- and cohort-specific contributions to population-level differences in parity-specific fertility patterns. The decomposition illustrates how high teenage fertility in the United States dominates the differences between these two countries in the time spent at different parities.

Residential proximity to a fertility clinic is independently associated with likelihood of women having ART and IUI treatment.

STUDY QUESTION: Is geographic proximity to a fertility clinic associated with the likelihood of women of reproductive age undertaking different forms of medically assisted fertility treatment? SUMMARY ANSWER: After adjusting for socioeconomic status (SES) and other confounders including a proxy for the need for infertility treatment, women who lived within 15 km of a fertility clinic were 21% more likely to undergo ART treatment and 68% more likely to undergo IUI treatment than those who lived further than 60 km away. WHAT IS KNOWN ALREADY: In most countries, patients living outside of metropolitan areas are more likely to be more socio-economically disadvantaged and to have less equitable access to healthcare. However, how a woman's residential proximity to fertility clinics predicts utilization of high-cost/high-technology treatment (ART) and low-cost/low-technology treatment (IUI) is limited, and whether socio-economic disadvantage explains much of the hypothesized lower utilization is unknown. Australia's universal insurance scheme provides supportive reimbursement for almost all ART and IUI treatment regardless of age or number of cycles, providing a unique setting to investigate disparities in access to infertility treatment. STUDY DESIGN, SIZE, DURATION: National population-based observation study of ART and IUI treatment utilization by women across socio-economic gradients and Australian residential locations between August 2015 and December 2017. PARTICIPANTS/MATERIALS, SETTING, METHODS: Universal insurance claims information on female patients who underwent ART or IUI were provided by Services Australia, comprising 67 670 female patients who accessed 162 795 ART treatments, and 10 211 female patients who accessed 19 615 IUI treatments over a 29-month period. Incidence rates by SES and proximity to fertility clinics were calculated to describe the number of women undergoing at least one ART or IUI treatment cycle per 1000 women of reproductive age (25-44). Treatment frequencies were calculated to describe the average number of ART or IUI treatment cycles per woman of reproductive age who had undergone at least one ART or IUI treatment during the study period. Poisson regression analyses were used to estimate the independent effect on accessibility to infertility treatment by geographic proximity (based on small area locations) to the closest fertility clinic after adjusting for SES, childbearing delay, remoteness area, and marital status. MAIN RESULTS AND THE ROLE OF CHANCE: On average, 19.1 women per 1000 women of reproductive age underwent at least one fresh or frozen ART cycle, with an average 2.3 ART cycles each, while 3.0 women per 1000 women of reproductive age received at least one IUI cycle, with an average of 1.6 IUI cycles each. After adjusting for SES and other confounders including a proxy for the need for infertility treatment, women who lived within 15 km of a fertility clinic were 21% more likely to undergo ART treatment and 68% more likely to undergo IUI than those who lived over 60 km away. Regardless of geographic location, there was a steady and independent gradient in access to ART treatment based on increasing SES, with women residing in the most advantaged residential quartile having a 37% higher rate of receiving ART treatment compared to those in the most disadvantaged quartile. The negative effect of social disadvantage on ART use became more pronounced as distance from a fertility clinic grew, indicating that the barriers to access to ART care caused by distance were further compounded by the level of socioeconomic advantage of the women's residential location. In contrast, socioeconomic status did not modify the likelihood of using IUI over and above the distance from a fertility clinic. In relation to IUI treatment, differences in utilization by SES disappeared after adjusting for geographic proximity to a fertility clinic, childbearing delay, remoteness area, and marital status. LIMITATIONS, REASONS FOR CAUTION: Information is aggregated by small geographic areas and it therefore may not reflect individual characteristics. Australia provides partial but comparably supportive reimbursement for both ART and IUI through its universal healthcare system and thus the results may not be fully generalizable to other settings. WIDER IMPLICATIONS OF THE FINDINGS: Residential proximity to a fertility clinic is a persistent barrier to accessing ART and IUI treatment, regardless of SES, even in countries characterized by supportive public funding, such as Australia. SES is less of a barrier to accessing IUI than ART, presumably driven by the lower cost and fewer clinic visits required with IUI treatment. Safe and effective fertility treatment should be available to all women regardless of where they live. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by the Australian National University Research scholarship and by the Higher Degree Research Fee Merit Scholarship. The authors have no conflict of interest. TRIAL REGISTRATION NUMBER: N/A.

Educational composition and parity contribution to completed cohort fertility change in low-fertility settings.

Extensive literature has documented the contribution of rising women's education to decreases in completed cohort fertility (CCF). A key question related to the education-fertility relationship is to what extent the decrease in fertility is the result of changes in educational composition vs changes in fertility behaviours within educational categories. This study quantified the effect of educational expansion on fertility levels by decomposing the overall change in CCF into educational composition and education-specific fertility, and explored the changes in parity-specific components of CCF by education for cohorts born between 1940 and 1970. The results show that, despite the decline in CCF being caused mostly by changes in fertility behaviours, educational composition had a considerable impact for some cohorts. The decline in third and higher-order births played a central role in the fall in CCF across educational groups, while the effects of transitions to first and second births varied substantially.

Pathways into childbearing delay of men and women in Australia.

Childbearing delay is a pervasive feature of Australian society, but little research has been conducted to examine how socio-economic factors are linked to childbearing timing among Australian men and women. This paper addresses this by analysing the timing of first childbirth for a large sample of Australian residents (N = 4,444). The findings indicate that childbearing delay is socially patterned and that life course experiences shape the risk of delaying childbearing across genders. Having a tertiary qualification delays the transition to parenthood, especially for women. An uninterrupted career prolongs time to parenthood for women but accelerates it for men. Low occupational prestige, being married and having been in only one co-residential union are associated with earlier parenthood for both men and women. For each increase in education level, not being married is associated with increasing levels of childlessness. Clear-cut gender differences are found in the relationship between childlessness and childbearing delay.