Research chronicle

Life expectancy in England & Wales has diverged from that of its high-income peers since 2011, raising concerns that the country may become an international laggard like the United States (US). Using the contour method, we decompose gaps in life expectancy between England & Wales and 20 individual high-income countries for males and females in 2019 into: (a) pre-existing differences in age- and cause-specific death rates in 2011; and (b) diverging trends in these rates between 2011 and 2019. Focusing on trends, we find that external mortality at young-to-middle ages, cardiometabolic mortality at middle-to-older ages, and dementia mortality at older ages contributed most to life expectancy gaps. Although England & Wales and the US shared adverse trends in cardiometabolic and external mortality, England & Wales experienced larger life expectancy gains. Our findings underscore the urgency of improving population health in England & Wales to avoid life expectancy falling further behind.

Full birth histories that enable analysis of mothers' ages at birth and birth intervals by parity are rare in historical data. Partial birth histories can be obtained from retrospective fertility surveys and census data that record the numbers of children ever born, children deceased, and ages of surviving co-resident children. In a 1988 article published in Population Studies, Luther and Cho proposed a method for reconstructing full birth histories by probabilistically imputing the ages of deceased and non-co-resident children, and in a 2020 article in Historical Methods, Hacker extended this method to historical census data from the United States. In this paper I further adapt the reconstruction method using a sample from the 1911 Census of England and Wales and census records linked from 1881 onwards; this reduces the number of missing observations in the partial birth histories. Birth histories based on linked data particularly improve estimates of duration-specific marital fertility for women who married and had children more than 15 years before the survey date.

ABSTRACT Background Life expectancy improved dramatically during the 20 th century. Whether more recent generations are also living longer in good health has serious implications for healthcare systems and the economy. Aim To synthesise evidence on cohort differences in physical and mental health from the British birth cohort studies, born 1946 to 2000-02. Method Electronic databases (MEDLINE, EMBASE, PsycInfo, Web of Science, up to 25 June 2024) were searched for pairwise combinations of the six cohort studies of interest or for terms indicating the use of at least two cohorts in the same study. Articles were eligible for inclusion if they compared the health of two or more included cohorts at similar ages (within 3 years). Results Results were summarised narratively. There was little evidence for improving health across successive cohorts born since 1946 when compared at the same age. For several outcomes – particularly obesity, mental ill-health and diabetes – prevalence of poor health was higher in more recent generations, a pattern we term “Generational Health Drift”. Many outcomes were self-reported, but studies using observer-measured outcomes (anthropometric measures and blood biomarkers) tended to support conclusions based on self-reports. Conclusion More research is needed to understand the drivers of this trend, shaped by changing exposure to preventable social and environmental risk factors across the lifecourse, and to monitor future trends in disability and functional limitation. The Generational Health Drift has serious implications for policy, planning, and funding allocation to be able to support a growing number of people living with chronic health conditions.

BACKGROUNDSince World War II, Britain has witnessed significant societal changes, including in relation to fertility.Robust longitudinal and cross-cohort research requires data harmonisation to create comparable fertility measures to understand the predictors and consequences of these changes across generations. OBJECTIVEThis paper describes newly created datasets on fertility histories that have been derived and harmonised across four longitudinal British studies of cohorts born between 1946 and 1990.The consistency with national statistics on fertility are examined. METHODSThe birth cohorts are: National Survey of Health and Development, born in 1946; the 1958 National Child Development Study; the 1970 British Cohort Study; Next Steps, born in 1989/90. RESULTSThe harmonised datasets include information on the cohort members' biological children at each survey sweep during childbearing age, such as whether they have children and if so how many, age of eldest and youngest child, number of boys and girls, and children by a previous partner.Additional variables related to non-biological children have been derived where possible.The percentage of female cohort members who have had at least one live birth and the number of children show a good degree of consistency with national statistics on fertility.

Summary A major reason why the difference between the number of baptisms recorded in Anglican registers and the number of births occurring was becoming greater was the increasing delay between birth and baptism. More and more children died before they had been baptised, or in circumstances which caused their baptism to go unrecorded. As long as burial registration was complete, estimates of the extent of the shortfall between births and baptisms may be made from a comparison of baptism and burial registers. When burial registration, too, began to falter, resort must be had to indirect methods of estimating underregistration both of births and deaths. Estimates are given of the changing levels of underregistration arising from this cause at half-century intervals between the late sixteenth and late eighteenth centuries. The exercise also brings to light evidence of the fluctuating level of infant mortality over the period and of changes in the relative importance of endogenous and exogenous mortality within the total infant mortality rate.

Delayed childbearing in advanced economies has increased reliance on assisted reproductive technologies (ART). Yet, how ART and especially donor egg treatments contribute to population-level fertility rates remains under-studied. Analysing all ART treatments in the UK (1991-2018), we document rising ART usage: ART-conceived births contributed 3.0 per cent to the total fertility rate in 2018 and 14.9 per cent to fertility rates among women aged 45-50. ART success rates show a clear age-related decline when using women's own eggs but remain consistent across age groups when using donor eggs. Consequently, from age 43 onwards, ART-conceived births result predominantly from donor egg treatments. Our findings indicate that fertility recuperation at advanced ages is unlikely to succeed with ART using a patient's own eggs; egg donation and egg freezing appear indispensable for supporting fertility at advanced ages with ART. This has significant implications for public health communication, as this fact is not widely known.

Health is rarely used as an explanatory variable in fertility studies in high-income contexts, unlike in low-income settings. Using the 1958 National Child Development Study, we explore how self-rated health (SRH) and body mass index (BMI) at age 23 relate to achievement of fertility goals by age 46. We find that worse SRH and a BMI outside the healthy range at age 23 are strongly associated with lower fertility and underachieving fertility goals. While poor SRH is associated with lower fertility mostly among men, BMI outside the healthy range at 23 is more significant for women. Additional analyses indicate that employment and union history partly mediate the effect of health on fertility, but health retains a substantive direct effect. Our findings suggest that health in early adulthood is an important determinant, whether direct or indirect, of family life-course trajectories. This paper endorses the inclusion of health as an explanatory variable in studies of fertility in high-income contexts.

This study uses census-linked administrative data to investigate childbearing trends by birth order in Britain over three decades. This is the first study to investigate longer-term changes in fertility dynamics in Britain by birth order and to compare parity-specific fertility by country. First-birth rates declined in the 1990s, slightly increased in the first decade of this century, and decreased thereafter, with changes in timing of parenthood responsible for these changes. Second- and third-birth rates declined in the 1990s but remained relatively stable in the early twenty-first century. Birth intervals remained unchanged, meaning that changes in quantum are responsible for trends in higher-order birth rates. Time trends are similar in England & Wales and Scotland but with significantly lower second- and third-birth rates in Scotland. Changes in population composition by education and ethnicity explain little of the aggregate fertility trends or between-country differences. Both countries have seen rapid declines in first-birth rates, especially among low-educated women.

The sense of belonging to the current neighbourhood may play a role in the transition to parenthood by indicating a feeling of being 'at home' and having access to social resources. However, previous research has indicated that individuals often move house in anticipation of parenthood, likely altering their connection to the neighbourhood in the process. With data from the UK Household Longitudinal Study (2009-23) and using logit regression, we examine the likelihood of a first birth. The results reveal that individuals with a higher sense of belonging to their neighbourhood are more likely to have a first child: especially recent movers compared with long-term residents. Furthermore, while long-distance movers generally show a lower probability of becoming parents, those with a high sense of belonging are as likely as short-distance movers to become parents. These findings suggest that socio-spatial factors play a role in the transition to parenthood.