It is well documented that physical activity is an important component of a healthy lifestyle and has numerous beneficial effects, both in terms of physical health and mental health. Participation in organised sports is a popular way of achieving the benefits of increased physical activity as well as developing social skills such as teamwork and discipline. However, alongside these benefits, participation in sport is not without risk. Sports-related injuries can range from minor strains and sprains to broken limbs and concussion, or even, in the most extreme cases, paralysis or death. There can also be potential long-term effects from these injuries such as chronic musculoskeletal problems or psychological effects. Longitudinal cohort studies are in a prime position to be able to chart such long-term effects. This Data Note describes the information available on sports/physical activity injuries along with sporting participation, ability and enjoyment (ages 4 to 30 years) within the ALSPAC study which has followed up the children involved into adulthood, along with measures of mental and physical health.

The aim of this data note is to describe data collected in 2022 on sexual history, attitudes, enjoyment and regret. Data were collected from mothers (age range 47–75 years (mean 60.0), n = 4653) their partners (age range 47-83 years (mean 62.9), n= 1945) and offspring (aged ~30 years, females n= 2702, males n=1366) in the Avon Longitudinal Study of Parents & Children (ALSPAC). Many of the questions asked are identical, or similar, to those collected in the British NATSAL (National Surveys of Sexual Attitudes & Lifestyles). Repeating the same questions in both ALSPAC generations allows for direct inter-generational comparisons within ALSPAC as well as across studies. Areas covered include age at sexual debut; having drunk alcohol, used drugs or contraception at sexual debut; the circumstances under which participants met their first sexual partner; sexual orientation; the Brief Sexual Attitudes Scale; regret at first sexual experience, lifetime experiences of sexual regret and the degree of regret, as well as the reason(s) for that regret; number of sexual partners both in the last two years and over their lifetime; current frequency and enjoyment of sex. ALSPAC provides a rich resource of data collected on a wide variety of topics including details of the participants’ environment, lifestyle, physical and mental health over the life span, including sexual experiences collected retrospectively from the parents, and from the age of 11 in the offspring. There are thus many opportunities for research on a wide variety of topics related to potentially risky and normal sexual behaviours, sexual health, functioning and well-being.

Information collected from the study of parents on their own religious and spiritual beliefs and behaviours during the first 9 years following the birth of the ALSPAC study children has been documented previously in a Data Note. Here we describe the data collected on their children’s exposures to, and participation in, religious and/or spiritual events during their childhoods (defined as <25 years). Information available includes their exposures whether via school, places of worship or more informal gatherings. We describe the variables available and those that, in retrospect, would have been valuable. For the available variables we show the frequencies of response and the differences between the boys and girls (using sex ascribed at birth). Ways in which researchers can apply for appropriate data to analyse are described.

Background: Lead is a neurotoxic metal that crosses the placenta freely. It has adverse effects on a range of birth outcomes. The few studies reporting on the associations of prenatal exposure to lead and child growth have had conflicting results. This study aimed to examine the effect of prenatal exposure to lead on children’s growth from 4 to 61 months of age. Methods: Pregnant women were enrolled in the UK Avon Longitudinal Study of Parents and Children (ALSPAC). Whole blood samples for pregnancies with a live birth were analysed for lead (n=4140). A 10% subsample of the offspring cohort (Children in Focus) were invited to clinics at 10 time points (4–61 months) at which anthropometric measurements were carried out; z-scores for height, weight and BMI were calculated using the 1990 British Growth Reference Standards. Associations between prenatal log10-lead concentrations and z-scores and other anthropometric measures were modelled using adjusted linear regression models in an imputed dataset for children who attended at least one clinic (n=574). Results: The median prenatal blood lead concentration was 3.60 (IQR 2.61–4.16) µg/dl. There was no evidence for any associations of prenatal lead exposure with z-scores for BMI, height or weight in adjusted models from age 4 to 61 months. There were no associations for other anthropometric measures including mid-upper arm circumference, head circumference and waist circumference. There was some evidence for a weakly positive effect of prenatal lead exposure on head circumference in girls at age 43 and 61 months (at 61 months unstandardised B coefficient 1.59 (95% CI 0.12, 3.16) cm, p=0.048) but not at other ages. Conclusions: There was no consistent evidence of associations between prenatal exposure to lead and measures of growth and anthropometry from age 4 to 61 months in this cohort of children in the UK.

Acute and chronic ear problems can lead to hearing loss. Temporary and persistent hearing loss during early and mid-childhood can impact speech and language development, behaviour and other developmental milestones. There is some evidence that the consequences may be long-term in influencing outcomes related to behaviour, social interaction and mental health into adulthood. Unlike most birth cohort studies, the Avon Longitudinal Study of Parents and Children (ALSPAC) has repeated measured aspects of hearing and ear related signs and symptoms in considerable detail during childhood. This enables the identification of consequences and preventive features that can be considered. In this, the first of two Data Notes, we outline the information collected from direct assessment of the study cohort, between the ages of 8 months and 15 years. This includes features related to ear conditions and hearing ability, and indicates the variables derived and the frequencies of the results obtained during childhood and adolescence.

Rotter’s introduction of Locus of Control (LOC) as part of his social learning theory in 1966 has generated a huge amount of research in this area. An internal LOC has been shown to be beneficial in almost every aspect of life including educational attainment, professional success, mental and physical health. An internal individual is more likely to perceive that their own actions can affect any given outcome, whilst an external individual believes that whatever happens to them is beyond their control (down to luck or chance). It is often triggered by a novel event – and depending on orientation may depend on how an individual copes with that event. The Avon Longitudinal Study of Parents & Children (ALSPAC) has measured LOC over time (detailed elsewhere), but this data note concentrates on the two most recent sweeps: fortuitously, collected both before and after the COVID pandemic (2020 and 2022) in both the parent and offspring cohorts. LOC measured at intervals over about 30 years in the parents and over 20 years in the offspring make an exciting resource for researchers in physical and mental health, ageing, well-being, education, entrepreneurial success, addictive behaviours, beliefs and behaviours, and resilience for example.

Objectives Lead and mercury are recognised as critical determinants of population health, especially for children and pregnant women. Few UK cohorts have measured lead or mercury in pregnant women since 1990. The aims of this study are to: (1) quantify lead and mercury exposures in a sample of pregnant women in the UK; (2) document concentrations over time in pregnant women in the UK; and (3) compare concentrations with international data.Design Whole blood samples were obtained from pregnant women in a quantitative arm of the Pregnancy, the Environment And nutRition Study in a cross-sectional observational study design. The samples were analysed by inductively coupled plasma mass spectrometry (Health and Safety Executive, Buxton, UK).Setting Community-based with recruitment through a hospital antenatal clinic in south-west England.Participants Women ≥18 years old and ≥11 weeks pregnant by last menstrual period.Primary outcome measures Whole blood lead and speciated mercury concentrations.Results The whole blood lead concentration was: mean 5.8 (SD 6.2), median 4.6 (IQR 3.5, 5.9), range 1.7–78.1 µg/L (n=262; gestational age range by scan 8.3–15.9 weeks). These values are about 84% lower than in pregnant women in the UK Avon Longitudinal Study of Parents and Children (ALSPAC; 1991–1992), about 47% lower than in the UK Born in Bradford (BiB) study (2007–2011) and about 34% lower than in White women in the UK Mother’s and Baby’s Exposure to Lead study (MaBEL; 2011). Blood total mercury concentration was: mean 0.83 (SD 0.64), median 0.69 (IQR 0.34, 1.19), range 0.07–3.40 (about 60% lower than in pregnant women in ALSPAC and about 37% lower than in BiB). These results are similar to contemporary concentrations found in Europe and the USA.Conclusions Blood concentrations of lead and mercury in pregnant women in the UK have declined considerably since the early 1990s. However, no safe levels have previously been identified for adverse effects on cognition, preterm birth rate or coronary heart disease prevalence. These data will contribute to the ongoing development of public health advice.Study registration ISTCTN92638336.

Background Lead is a neurotoxic metal that crosses the placenta freely. It has adverse effects on a range of birth outcomes. The few studies reporting on the associations of prenatal exposure to lead and child growth have had conflicting results. This study aimed to examine the effect of prenatal exposure to lead on children’s growth from 4 to 61 months of age. Methods Pregnant women were enrolled in the UK Avon Longitudinal Study of Parents and Children (ALSPAC). Whole blood samples for pregnancies with a live birth were analysed for lead (n = 4140). A 10% subsample of the offspring cohort (Children in Focus) were invited to clinics at 10 time points (4–61 months) at which anthropometric measurements were carried out; z-scores for height, weight and BMI were calculated using the 1990 British Growth Reference Standards. Associations between prenatal log 10-lead concentrations and z-scores and other anthropometric measures were modelled using adjusted linear regression models in an imputed dataset for children who attended at least one clinic (n = 574). Results The median prenatal blood lead concentration was 3.60 (IQR 2.61–4.16) μg/dl. There was no evidence for any associations of prenatal lead exposure with z-scores for BMI, height or weight in adjusted models from age 4 to 61 months. There were no associations for other anthropometric measures including mid-upper arm circumference, head circumference and waist circumference. There was some evidence for a weakly positive effect of prenatal lead exposure on head circumference in girls at age 43 and 61 months (at 61 months unstandardised B coefficient 1.59 (95% CI 0.12, 3.16) cm per 1 unit log10 μg/dl, p = 0.048) but not at other ages. Conclusions There was no consistent evidence of associations between prenatal exposure to lead and measures of growth and anthropometry from age 4 to 61 months in this cohort of children in the UK.

The aim of this data note is to describe data collected in 2022 on sexual history, attitudes, enjoyment and regret. Data were collected from mothers (age range 47-75 years (mean 60.0), n = 4653) their partners (age range 47-83 years (mean 62.9), n= 1945) and offspring (aged ~30 years, females n= 2702, males n=1366) in the Avon Longitudinal Study of Parents & Children (ALSPAC). Many of the questions asked are identical, or similar, to those collected in the British NATSAL (National Surveys of Sexual Attitudes & Lifestyles). Repeating the same questions in both ALSPAC generations allows for direct inter-generational comparisons within ALSPAC as well as across studies. Areas covered include age at sexual debut; having drunk alcohol, used drugs or contraception at sexual debut; the circumstances under which participants met their first sexual partner; sexual orientation; the Brief Sexual Attitudes Scale; regret at first sexual experience, lifetime experiences of sexual regret and the degree of regret, as well as the reason(s) for that regret; number of sexual partners both in the last two years and over their lifetime; current frequency and enjoyment of sex. ALSPAC provides a rich resource of data collected on a wide variety of topics including details of the participants' environment, lifestyle, physical and mental health over the life span, including sexual experiences collected retrospectively from the parents, and from the age of 11 in the offspring. There are thus many opportunities for research on a wide variety of topics related to potentially risky and normal sexual behaviours, sexual health, functioning and well-being.

Information collected from the study of parents on their own religious and spiritual beliefs and behaviours during the first 9 years following the birth of the ALSPAC study children has been documented previously in a Data Note. Here we describe the data collected on their children’s exposures to, and participation in, religious and/or spiritual events during their childhoods (defined as <25 years). Information available includes their exposures whether via school, places of worship or more informal gatherings. We describe the variables available and those that, in retrospect, would have been valuable. For the available variables we show the frequencies of response and the differences between the boys and girls (using sex ascribed at birth). Ways in which researchers can apply for appropriate data to analyse are described.

Background The FRAXE site on the X-chromosome has a variable number of trinucleotide repeats. The rare condition Fragile XE has >200 repeats, but most X chromosomes have <60 such repeats, with evidence of a bimodal distribution. It is known that when the number of repeats is <60, the repeat number can increase from mother to son, which raises the question as to whether there is an evolutionary advantage in the increased size of these repeats. This paper investigates whether the higher of the <60 repeats are associated with neurocognitive differences among boys in a general population. We hypothesised that although there was previous evidence of a link between higher numbers of repeats in the boys in this population having maternal grandmothers with schizophrenia, there may be cognitive or behavioural advantages to their grandsons of increased levels of repeats. Methods We compared 1951 behavioural, psychiatric, and cognitive outcomes of 5060 boys from the Avon Longitudinal Study of Parents and Children (ALSPAC) using a phenome scan. Results We found that boys with relatively high levels of repeats (>24) had a higher risk of certain neurocognitive outcomes (P<0.01). Boys with >24 repeats were more likely to report: (a) psychosis-like experiences; (b) increased ability to recognise facial signs of anger; (c) increased risk of eating disorders; (d) increased likelihood of smoking cigarettes and using illicit drugs during adolescence than would be expected by chance. There was no sign of associations with cognitive abilities. Conclusions We concluded that there was little evidence that higher levels of the normal range of FRAXE repeats were associated with a difference in cognitive abilities, but there was evidence of increased reports of psychotic-like experiences and other behaviour problems in this group. There was no evidence of evolutionary neurocognitive advantage.

Background Many studies use single-item variables to measure religiosity, such as religious belief, identity or service attendance. However, there are many different hypothesised dimensions of religiosity and it is often unclear how these single-item measures may map onto these theorised constructs. ALSPAC (Avon Longitudinal Study of Parents and Children) primarily relied on single-items to measure religiosity, but more recently has included validated questionnaires (DUREL [Duke University Religion Index] and I/EMSS [Intrinsic/Extrinsic Measurement: I/E-Revised and Single-Item Scales]). This paper aims to: i) assess whether the validated measures load together as expected in ALSPAC; and ii) understand which religiosity dimensions the single-item measures relate to. Methods Twenty religiosity questions were asked to ALSPAC offspring and parents approximately 28 years after the offspring’s birth. We used three exploratory factor analyses to assess how the different items related to one another on: i) the pre-validated DUREL and I/EMSS measures to examine whether they represent distinct dimensions, as intended ; ii) all 20 religiosity measures; and iii) the pre-validated measures and the single-item measures also used at previous ALSPAC timepoints (13 measures). Results The first factor analysis showed that, beyond a single religiosity factor, these pre-validated items did not always work as intended. For instance, intrinsic religiosity items loaded together, but extrinsic religiosity items were often separated. The second and third analyses showed that single-item measures did not relate well to hypothesised dimensions of religion but did form two broad factors of belief-based and behaviour-based items. Results were broadly comparable across both ALSPAC generations. Conclusions These results show that pre-validated measures of religiosity do not always behave as expected in ALSPAC, while the single-item measures do not easily map onto specific dimensions of religiosity. These results will help researchers better understand the ALSPAC religiosity data and inform analyses using these data.

Background The FRAXE site on the X-chromosome has a variable number of trinucleotide repeats. The rare condition Fragile XE has >200 repeats, but most X chromosomes have <60 such repeats, with evidence of a bimodal distribution. It is known that when the number of repeats is <60, the repeat number can increase from mother to son, which raises the question as to whether there is an evolutionary advantage in the increased size of these repeats. This paper investigates whether the higher of the <60 repeats are associated with neurocognitive differences among boys in a general population. We hypothesised that although there was previous evidence of a link between higher numbers of repeats in the boys in this population having maternal grandmothers with schizophrenia, there may be cognitive or behavioural advantages to their grandsons of increased levels of repeats. Methods We compared 1951 behavioural, psychiatric, and cognitive outcomes of 5060 boys from the Avon Longitudinal Study of Parents and Children (ALSPAC) using a phenome scan. Results We found that boys with relatively high levels of repeats (>24) had a higher risk of certain neurocognitive outcomes (P<0.01). Boys with >24 repeats were more likely to report: (a) psychosis-like experiences; (b) increased ability to recognise facial signs of anger; (c) increased risk of eating disorders; (d) increased likelihood of smoking cigarettes and using illicit drugs during adolescence than would be expected by chance. There was no sign of associations with cognitive abilities. Conclusions We concluded that there was little evidence that higher levels of the normal range of FRAXE repeats were associated with a difference in cognitive abilities, but there was evidence of increased reports of psychotic-like experiences and other behaviour problems in this group. There was no evidence of evolutionary neurocognitive advantage.

Background: Psychotic experiences (PEs) are common in the general population, and can be an early sign of psychotic disorders, which can have a large impact on people’s lives. Understanding the causes and consequences of PEs is therefore important, both for identifying potential causal risk factors for PEs and for exploring how PEs may subsequently affect people’s beliefs and behaviours. To investigate this, we focus on potential bidirectional causality between PEs and religiosity – a topic which remains under-researched and currently with a weak evidence base – using large-scale data from a UK longitudinal birth cohort. Methods: We used data from the Avon Longitudinal Study of Parents and Children (ALSPAC). PEs were assessed using semi-structured interviews at age 24 (for PEs since age 12) and self-reported questionnaires at age 32 (for PEs in the past year). Religiosity was self-reported at age 28, and included questions on religious beliefs, identity and service attendance. Multivariable regression models, adjusted for relevant confounders, analysed bidirectional associations between PEs and religiosity (i.e., whether PEs from age 12-24 potentially cause religiosity at age 28, and whether religiosity at age 28 potentially causes PEs at age 32). Multiple imputation was used to impute missing data and boost statistical power, with g-computation used to calculate our marginal causal contrasts of interest. Results: Interview-rated PEs between age 12-24 were associated with a greater probability of religious belief; participants with PEs were 7.8%-points (95% confidence/compatibility interval [CI] = 1.9% to 13.7%) less likely to answer ‘no’ to believing in God, and 5.7%-points (95% CI = 0.7% to 10.7%) more likely to answer ‘yes’. Similar patterns were observed for religious identity (PEs associated with a 5.6%-point [95% CI = 0.2% to 11.0%] increase in identifying as religious), but with weaker evidence of an association with religious service attendance (PEs associated with a 1.7%-point [95% CI = -1.0% to 4.4%] increase in regular attendance). Religious belief at age 28 was also associated with an increased probability of self-reported PEs at age 32 (5.7%-points [95% CI = 1.8% to 9.5%]), with effects for religious identity (2.1%-points [95% CI = -0.9% to 5.0%] increase in PEs) and religious attendance (5.6%-point [95% CI = -1.8% to 12.9%] increase in PEs) in the same direction but weaker and/or plausibly null. Conclusion: To the extent these results can be given a causal interpretation, these findings suggest a potential bidirectional causal relationship between PEs and religiosity, especially regarding religious beliefs. Further research is needed to explore whether these results are replicable and generalisable across populations, in addition to whether religiosity may moderate or mediate the long-term impact of PEs on mental health outcomes.

Background: There is considerable evidence that breast feeding has a beneficial effect on the neurocognition of a child. However, most studies have confined their attention to the Intelligence Quotient (IQ), tending to ignore other aspects of neurodevelopment. Methodology: Here we present the relationship between breast feeding for at least 6 months with 373 neurocognitive outcomes measured from infancy through to late adolescence using data collected in the Avon Longitudinal Study of Parents and Children (ALSPAC). We first examined unadjusted regression associations with breast feeding at age 6 months. Where the unadjusted p-value was < 0.0001 (n = 152 outcomes), we adjusted for social and other factors. Results: This resulted in 42 outcomes with adjusted associations at p < 0.001. Specifically, these included associations with full-scale IQ at ages 8 and 15 years (adjusted mean differences [95% confidence interval (CI)] +4.11 [95% CI 2.83, 5.39] and +5.12 [95% CI 3.57, 6.67] IQ points, respectively, compared to not breastfeeding for 6 months). As well as the components of IQ, the other phenotypes that were strongly related to breast feeding for at least 6 months were measures of academic ability (reading, use of the English language and mathematics). In accordance with the literature, we show that children who are breast fed are more likely to be right-handed. The one association that has not been recorded before concerned aspects of pragmatic speech at 9 years where the children who had been breast fed were shown to perform more appropriately. Conclusions: We conclude that breast feeding for at least 6 months has beneficial effects on a number of neurocognitive outcomes that are likely to play a major part in the offspring’s future life course. We point out, however, the possibility that by using such stringent p-value criteria, other valid associations may have been ignored.

There is considerable discussion concerning the recent increase in the prevalence of overweight/obesity in children and adults. Although it is assumed that current diet and sedentary behavior are key contributors, these factors do not seem to be the only characteristics responsible. In this paper we summarize the findings we have obtained when assessing whether exposures in previous generations may have played a part in this change over time. In particular, we show that ancestral smoking may be an important contributor. We used data collected from parents and grandparents by the Avon Longitudinal Study of Parents and Children (ALSPAC), which has followed children born in 1991-1992 to women resident in south-west England. We have shown that ancestral smoking characteristics were associated with fetal growth and with increased measures of adiposity in their children and grandchildren. Here we describe the detailed findings of the ancestral exposure to cigarette smoking of ancestors at various time points using ALSPAC data and indicate the support for the findings in other cohorts. Since body mass index (BMI) can be a measure of lean (muscle) mass as well as fat mass, we concentrate on associations with body composition from dual-energy x-ray absorptiometry (DXA). Few birth cohorts have collected data on smoking of individuals in the male line and few have used details of fat, bone, and lean mass. Findings concerning grandmaternal smoking in pregnancy and pre-pubertal smoking of male ancestors were nevertheless replicated. We consider the likelihood of epigenetic explanations for these findings.

Relations between religion and mental health have been studied extensively, yet whether associations are causal remains uncertain. Here, we use longitudinal data from the parental generation of the Avon Longitudinal Study of Parents and Children (ALSPAC), based in the UK, to assess: i) whether religiosity may cause subsequent depression and anxiety; ii) whether depression and anxiety may cause subsequent religiosity; and iii) whether there are gender differences in the above associations. All analyses were pre-registered, and adjusted for baseline confounders, exposures and outcomes in an attempt to rule out reverse causality and confounding bias. We found little conclusive evidence that religiosity was associated with subsequent mental health, or that mental health was associated with subsequent religiosity. Some weak associations were reported, but effect sizes were small and largely consistent with null effects. Small differences by gender were found, with religiosity marginally associated with better mental health in women and worse mental health in men, but the inconsistency of the results and the wide margins of error mean that firm conclusions cannot be made. In sum, in this UK population we find little evidence for bidirectional causation between religion and mental health, or for large differences in these associations by gender.

The Avon Longitudinal Study of Parents and Children (ALSPAC) is a longitudinal study following ~14,000 children from pregnancy through until adulthood. They were all born to women resident during pregnancy in a geographic area which comprised the city of Bristol, surrounding suburbs, rural areas, villages and towns. During their childhood almost all attended either state or private schools. The present Data Note describes the basic details of the schools attended by the cohort of children born in 1991–2, obtained by linking the names of the cohort children to the schools they attended during each school year and then anonymising the data. Details include the size of school in terms of the number of children enrolled, school sex composition, whether it is a Christian faith school (including the type of faith), whether it is fee-paying, and whether it is a boarding school. This document includes details as to how scientists can obtain the data for analysis in regard to other aspects of the children involved.