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.

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 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: 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.

Background When the Avon Longitudinal Study of Parents and Children (ALSPAC) was planned, it was assumed that the clinical obstetric data would be easily accessible from the newly developed National Health Service computerised ‘STORK’ system. Pilot studies, however, showed that, although fairly accurate in regard to aspects of labour and delivery, it was, at the time (1990-2), inadequate for identifying the full antenatal and postnatal details of clinical complications and treatments of the women in the Study. Methods A scheme was therefore developed to train research staff to find and abstract relevant details from clinical records onto proformas designed for the purpose. Extracting such data proved very time consuming (up to six hours for complicated pregnancies) and consequently expensive. Funding for the enterprise was obtained piecemeal using specific focussed grants to extract data for subsamples of the Study, including a random sample to serve as controls. Results To date, detailed records have been completed for 8369 pregnancies, and a further 5336 (13,705 in total) have complete details on specific prenatal areas, including serial measures of maternal blood pressure, proteinuria and weight. In this Data Note we describe the information abstracted from the obstetric medical records concerning the mother during pregnancy, labour, delivery and the first two weeks of the puerperium. Information abstracted relating to the fetus (including fetal monitoring, presentation, method of delivery) and neonate (signs of asphyxia, resuscitation, treatment and well-being) have been described in a further Data Note. Conclusions These data add depth to ALSPAC concerning ways in which the signs and symptoms, procedures and treatments of the mother prenatally, intrapartum and postnatally, may impact on the long-term health and development of both mother and child. They augment the data collected from the mothers’ questionnaires (described elsewhere) and the ‘STORK’ digital hospital data.

Mainstream religious beliefs and behaviours have been shown to have positive effects on health and well-being, but there has been increasing secularisation in the West over time. With concurrent increases in those stating they have no religion (the 'nones') there are increasing numbers now describing themselves as humanist, 'spiritual but not religious' or who have sought alternative forms of belief. Others have formed their own beliefs using elements of different belief systems. This trend is reflected in ALSPAC data with larger proportions considering themselves as 'nones', agnostic or atheist, and about 3% of parent participants consistently stating they had 'other' beliefs. The main aim of this paper is to describe the coding of the Christian denominations, world religions, non-mainstream beliefs (NMB) and non-religious groups derived from the text-based data collected from the original mother and partner cohorts (G0). This spans a period of ~28 years from pregnancy onwards. We also describe the coding of text-based responses from their offspring (G1) collected at ages 27+ and 29+. The creation of this coded data will enable researchers to compare between the Christian denominations and/or other belief groups taken from two generations alongside the rich resource of physical and mental health, behavioural and social data that exists within ALSPAC.

Background: Previous studies using the Avon Longitudinal Study of Parents and Children (ALSPAC) have shown that if men commenced smoking prior to the onset of puberty their sons, their granddaughters and great-granddaughters were more likely to have excess fat (but not lean) mass during childhood, adolescence and early adulthood. In this study we assess associations between ancestral smoking during adolescence (ages 11–16 years) with fat and lean mass of subsequent generations at two ages. Methods: We analysed data on exposures of grandparents and great-grandparents collected by ALSPAC. The outcomes were the fat masses of their grandchildren and great-grandchildren measured at ages 17 and 24. Measures of lean mass were used as controls. Adjustment was made for 8–10 demographic factors using multiple regression. Results: We found associations between adolescent smoking of the paternal grandfathers and the adjusted fat mass of their grandchildren, but no associations with the grandchildren’s lean mass. Grandchildren at age 17 had an average excess fat mass of +1.65 [95% CI +0.04, +3.26] Kg, and at age 24 an average excess of +1.55 [95% CI -0.27, +3.38] Kg. Adolescent smoking by the maternal grandfather showed similar, but weaker, associations: at 17 an average excess fat mass of +1.02 Kg [95% CI -0.20, +2.25] Kg, and at 24 an average excess of +1.28 [95% CI -0.11, +2.66] Kg. There were no pronounced differences between the sexes of the children. For the great-grandparents there were few convincing results, although numbers were small. Conclusions: We have shown associations between grandfathers’ smoking in adolescence and increased fat (but not lean) mass in their children. Confirmation of these associations is required, either in a further data set or by demonstrating the presence of supportive biomarkers.

At the time of planning ALSPAC there was accumulating evidence that abuse and other childhood traumas were related to psychiatric problems later in life. In addition, the age at which such trauma occurred was likely to be important in influencing its long-term impact. Detailed data was therefore collected from enrolled women on traumatic events occurring during their own childhoods, along with their age at the time. The questionnaire entitled ‘About Yourself’ was sent out to expectant women who had enrolled in the study, which included a page in the form of a grid (an events diary) with one row per year of childhood and columns for recording where she was living at the time, who was looking after her, and any traumatic events that occurred. These free-text responses were then coded, and any events were assigned a score indicating the level of trauma the event was likely to have caused on a scale of 1 (highly traumatic) to 6 (least traumatic). This paper describes the variety of text data collected and how it was coded. The ALSPAC study has a great deal of follow-up data collected on the original respondents, as well as on their parents and grandparents, partners, offspring and their grandchildren, providing huge potential for analyses on the antecedents and outcomes of adverse childhood events across multiple generations.

Background: Fetal exposure to paracetamol (acetaminophen) has been shown to be associated with asthma and other atopic disorders, as well as behavioural problems including hyperactivity, in childhood. However, there is little information on scholastic abilities among children exposed to paracetamol in pregnancy.Objectives: To determine whether there are any differences in scholastic abilities among the offspring of women who ingested paracetamol during pregnancy compared with non-exposed children.Methods: Mothers enrolled in the Avon Longitudinal Study of Parents and Children (ALSPAC) had recorded the frequency with which they had taken the medication over two time periods during pregnancy: i) the first 18 weeks and ii) 18–32 weeks. The offspring have been followed up ever since. For this study we use as outcomes: a) 14 tests of ability at reading and 2 of spelling using the study’s tests and the national education system test results; b) 6 of mathematical abilities including tests of arithmetic and mathematical reasoning, and c) 1 of scientific understanding. Multiple regression was used, adjusting for 15 different exposures including reasons for taking the medication as well as demographic features.Results: Almost all unadjusted and adjusted mean differences were negative (i.e., those exposed to maternal intake of paracetamol did less well), but negative associations for exposures between 18 and 32 weeks of gestation were much more evident than for exposures earlier in pregnancy. Of the later exposures, after adjustment, 12 of the 23 scholastic tests were associated with prenatal exposure to paracetamol at p < 0.05. These negative effects were found in the girls (12 tests at p < 0.05) but not boys (0 tests at p < 0.05).Conclusion: Evidence from this longitudinal study suggests that maternal exposure to paracetamol is associated with disadvantages to the offspring in scholastic abilities such as mathematics and reading at secondary school ages. This raises the question as to whether there are longer-lasting effects on educational attainment from age 15 years onwards, including at university level. Clearly these results should be tested in other settings, but meanwhile they add to a growing accumulation of known adverse effects of exposure to paracetamol in pregnancy.

Introduction: Within human epidemiological studies, associations have been demonstrated between grandparental exposures during childhood and grandchildren’s outcomes. A few studies have assessed whether asthma has ancestral associations with exposure to cigarette smoking, but results have been mixed so far. Material and methods: In this study we used four generations: (F0 great-grandparents, F1 grandparents, F2 parents, F3 study children) of the Avon Longitudinal Study of Parents and Children (ALSPAC) to determine whether there is evidence of associations between asthma in generations F2 or F3 and exposures to severe trauma in childhood and/or active cigarette smoking during the adolescence of grandmothers and grandfathers in generations F0 and F1 respectively, or of a history of a F0 or F1 grandmother smoking during pregnancy. Results: We have shown that: a) stress exemplified by the death of a F1 grandparent’s parent during the grandparents’ childhood was associated with increased risk of asthma in generation F3, especially if the grandparent involved was the paternal grandmother; b) if the grandparents of generations F0 or F1 smoked during adolescence (i.e. < 17 years), their grandchildren in generations F2 and F3 were more likely to have a history of asthma; c) paternal F1 grandmother’s smoking in pregnancy was associated with her F3 grandchild’s asthma at age 7; d) There were differences between the results for the grandsons and granddaughters of the paternal grandmother with exposure to smoking in adolescence and with smoking in pregnancy. e) The addition of all of the individual exposure variables to the different analyses often provided a considerable increase in goodness of fit compared with only adding demographic factors associated with asthma at P < 0.10 such as social class; this was particularly true when all four exposure variables were combined in one model, suggesting possible synergistic effects between them. Discussion: We have shown associations between all four types of exposure to the grandparents to be associated with asthma in the grandchildren, such that the results both depended on whether the male or female line was involved, and the sex of the grandchildren. It was notable that the paternal grandmother was particularly involved in many of the associations. We emphasize that these are exploratory analyses, that asthma diagnostic criteria likely changed over time and may not be consistent between generations, and that the results should be tested in other cohorts.

Objective To determine whether early ear and upper respiratory signs are associated with the development of high levels of autistic traits or diagnosed autism. Design Longitudinal birth cohort: Avon Longitudinal Study of Parents and Children (ALSPAC). Setting Area centred on the city of Bristol in Southwest England. Eligible pregnant women resident in the area with expected date of delivery between April 1991 and December 1992 inclusive. Participants 10 000+ young children followed throughout their first 4 years. Their mothers completed three questionnaires between 18–42 months recording the frequency of nine different signs and symptoms relating to the upper respiratory system, as well as ear and hearing problems. Outcome measures Primary—high levels of autism traits (social communication, coherent speech, sociability, and repetitive behaviour); secondary—diagnosed autism. Results Early evidence of mouth breathing, snoring, pulling/poking ears, ears going red, hearing worse during a cold, and rarely listening were associated with high scores on each autism trait and with a diagnosis of autism. There was also evidence of associations of pus or sticky mucus discharge from ears, especially with autism and with poor coherent speech. Adjustment for 10 environmental characteristics made little difference to the results, and substantially more adjusted associations were at p<0.001 than expected by chance (41 observed; 0.01 expected). For example, for discharge of pus or sticky mucus from ears the adjusted odds ratio (aOR) for autism at 30 months was 3.29 (95% CI 1.85 to 5.86, p<0.001), and for impaired hearing during a cold the aOR was 2.18 (95% CI 1.43 to 3.31, p<0.001). Conclusions Very young children exhibiting common ear and upper respiratory signs appear to have an increased risk of a subsequent diagnosis of autism or demonstrated high levels of autism traits. Results suggest the need for identification and management of ear, nose and throat conditions in autistic children and may provide possible indicators of causal mechanisms.

Background: The COVID-19 pandemic resulted in increased rates of mental health problems. We examined the possible role of the personality characteristic, Locus of Control (LOC), in moderating pandemic-induced stress.Methods: The UK-based Avon Longitudinal Study of Parents & Children (ALSPAC), 7021 adults (mean ages: women 57.6 (SD = 4.48); partners 60.5 (SD = 5.36)) responded to a 2020 questionnaire which included a generalised measure of LOC. Between March 2020-January 2021, questionnaires focussed on the pandemic were administered, which included measures of mental health. Over 60 % of respondents completed questionnaires at three timepoints of interest.Results: In those with an internal LOC higher rates of positive well-being and reduced likelihood of anxiety and depression were shown compared to those who were external, e.g. after adjustment for socioeconomic/de-mographic factors mean differences in well-being score for internal compared with external women was +2.01 (95%CI +1.02,+2.10) p = 0.0001; for their partners +2.52 (95%CI +1.22,+3.82) p = 0.0002. External women were more likely than internals to have depression (adjusted OR 3.41 [95%CI 1.77,6.57] p < 0.0005.Limitations: Attrition is a problem in this 30-year-old longitudinal cohort. Those still participating are more likely to have higher education and SES levels, be female and have an internal LOC. This population suffers from a lack of ethnic diversity.Conclusions: Having an internal LOC positively moderated the effects of pandemic-induced stress on the fre-quency of anxiety and depression in middle-age. Programmes geared to raise internality and coping strategies may have long-term benefits on well-being in stressful situations, especially for women and frontline health professionals.

Background: Research in non-genetic inheritance indicates that grandparents’ smoking habits and their childhood experiences of trauma can influence the physical and psychological attributes of their grandchildren. This was particularly apparent for outcomes such as autism and obesity where the population prevalence changed over time. Other factors which have changed temporally include religious and spiritual beliefs (RSBs) which have been declining in Western populations. Methods: We used data from the Avon Longitudinal Study of Parents and Children (ALSPAC) to explore whether grandparental exposures were associated with the religious and/or spiritual beliefs of their grandchildren. In line with other inter/trans-generational human studies we predicted that: (P1) grandparents’ childhood exposures to cigarette smoking (whether in utero or by active smoking) and/or exposure to traumatic events during childhood will be associated with their grandchild’s RSB; (P2) associations will differ between maternal and paternal lines of inheritance; (P3) relationships will vary with age at grandparental exposure, and (P4) associations will differ between grandsons and granddaughters. Results: We found significant associations between the grandchild’s RSB and both the grandparents’ smoking and their childhood trauma histories (P1 supported). These associations were mainly found down the maternal line (P2 possibly supported) and results varied with age of exposure of the grandparents; being strongest for in utero exposure of cigarette smoke and for pre-puberty exposure of traumatic events (P3 supported), and that granddaughters were more affected than grandsons (P4 supported). Conclusions: We hope that these results will motivate collection of similar data to further evaluate these questions in other populations, including a possible role for biological mechanisms.

Previously, using data from the Avon Longitudinal Study of Parents and Children (ALSPAC) we showed that sons of fathers who had started smoking regularly before puberty (< 13 years) had increased fat mass during childhood, adolescence, and early adulthood. We now show that if the paternal grandfather had started smoking pre-puberty, compared with later in childhood (13–16 years), his granddaughters, but not grandsons, had evidence of excess fat mass at two ages: mean difference + 3.54 kg; (P with 1-tailed test) = 0.043 at 17 years, and + 5.49 kg; (P 1 = 0.016) at age 24. When fathers of maternal grandfathers had started smoking pre-puberty, their great-granddaughters, but not great-grandsons, had excess body fat: + 5.35 kg (P 1 = 0.050) at 17, and + 6.10 kg (P 1 = 0.053) at 24 years. Similar associations were not found with lean mass, in a sensitivity analysis. To determine whether these results were due to the later generations starting to smoke pre-puberty, further analyses omitted those in subsequent generations who had smoked regularly from < 13 years. The results were similar. If these associations are confirmed in another dataset or using biomarkers, this will be one of the first human demonstrations of transgenerational effects of an environmental exposure across four generations.

There are few studies that chart the ways in which the religious beliefs and practices of parents and their offspring vary over time. Even fewer can relate this to aspects of their physical and mental health or distinguish the different facets of the environment that may have influenced the development or loss of religious/spiritual belief and behaviours over time. This paper describes the recent data collection in the Avon Longitudinal Study of Parents and Children (ALSPAC) on the beliefs and behaviours of the study parents some 27-28 years after the first measures were collected. Questions that were previously administered to the mother and her partner on religion, spirituality, behaviours, and beliefs (RSBB) were repeated for the fourth time, together with enhanced data on RSBB. The new data are described and compared with previous responses. The most notable difference between the 9 year and the 2020 sweep was the increase of professed non-believers in both the mothers (17.5% vs 29.8%) and partners (31.9% vs. 45.3%). As expected, on each occasion study partners were less likely to acknowledge RSBB compared to the study mothers. In the latest sweep, respondents were less likely to be unsure if they believed and more likely to not believe. Responses to “Do you believe in God or a divine power?” in mothers ranged from 49.9% stating ‘yes’ antenatally to 43.5% doing so in 2020; 14.9% vs 29.8% for ‘no’ and 35.2% to 26.6% for ‘not sure’. For partners, the corresponding figures are: ‘yes’ 37.0% vs. 30.0%; ‘no’ 28.6% vs. 45.3% and ‘not sure’ 34.5% vs. 24.6%. We plan to undertake detailed analyses of the antecedents and consequences of RBSS. All data are available for use by interested researchers.

Although there are many examples in the experimental literature of an environmental exposure in one generation impacting the phenotypes of subsequent generations, there are few studies that can assess whether such associations occur in humans. The Avon Longitudinal Study of Parents and Children (ALSPAC) has, however, been able to determine whether there are associations between grandparental exposures and their grandchildren's development. Several of our studies, including sensitivity to loud noise, have shown associations between a grandmother smoking in pregnancy and the phenotype of the grandchild. These results were mostly specific to the sex of the grandchild and to whether the prenatal (i.e. during pregnancy) smoking occurred in the maternal or paternal grandmother. Here, we have used ancestral data on prenatal smoking among the grandmothers of the ALSPAC index children to examine possible effects on the grandchild's ability to detect the bitter taste of PROP (6 n-propylthiouracil), distinguishing between the 10% deemed 'extreme tasters', and the rest of the population (total N = 4656 children). We showed that grandchildren whose paternal (but not maternal) grandmothers had smoked in pregnancy were more likely than those of non-smoking grandmothers to be extreme tasters [odds ratio (OR) 1.28; 95% confidence interval (CI) 1.03, 1.59] and that this was more likely in granddaughters (OR 1.42; 95% CI 1.03, 1.95) than grandsons (OR 1.18; 95% CI 0.88, 1.60). This pattern of association between paternal foetal exposure and the granddaughter's development has been found with several other outcomes, suggesting that investigations should be undertaken to investigate possible mechanisms.

Background: Previous studies using the Avon Longitudinal Study of Parents and Children (ALSPAC) have shown that if men commenced smoking prior to the onset of puberty their sons, their granddaughters and great-granddaughters were more likely to have excess fat (but not lean) mass during childhood, adolescence and early adulthood. In this study we assess associations between ancestral smoking during adolescence (ages 11–16 years) with fat and lean mass of subsequent generations at two ages. Methods: We analysed data on exposures of grandparents and great-grandparents collected by ALSPAC. The outcomes were the fat masses of their grandchildren and great-grandchildren measured at ages 17 and 24. Measures of lean mass were used as controls. Adjustment was made for 8–10 demographic factors using multiple regression. Results: We found associations between adolescent smoking of the paternal grandfathers and the adjusted fat mass of their grandchildren, but no associations with the grandchildren’s lean mass. Grandchildren at age 17 had an average excess fat mass of +1.65 [95% CI +0.04, +3.26] Kg, and at age 24 an average excess of +1.55 [95% CI -0.27, +3.38] Kg. Adolescent smoking by the maternal grandfather showed similar, but weaker, associations: at 17 an average excess fat mass of +1.02 Kg [95% CI -0.20, +2.25] Kg, and at 24 an average excess of +1.28 [95% CI -0.11, +2.66] Kg. There were no pronounced differences between the sexes of the children. For the great-grandparents there were few convincing results, although numbers were small. Conclusions: We have shown associations between grandfathers’ smoking in adolescence and increased fat (but not lean) mass in their children. Confirmation of these associations is required, either in a further data set or by demonstrating the presence of supportive biomarkers.

Health advice to pregnant women concerning consumption of mercury-containing foods has resulted in anxiety, with subsequent avoidance of fish consumption during pregnancy. However, seafood contains many nutrients crucial for children's growth and development. Longitudinal studies in the Seychelles, where fish is a major component of the diet, have not demonstrated harmful cognitive effects in children with increasing maternal mercury levels. Is the same true in a more developed country (the UK) where fish is eaten less frequently? We review publications using data collected by the Avon Longitudinal Study of Parents and Children (ALSPAC) to address this topic. Total mercury levels were measured in maternal whole blood and umbilical cord tissue. Offspring were followed throughout childhood, especially their cognitive development. No adverse associations were noted. Significantly beneficial associations with prenatal mercury levels were shown for total and performance IQ, mathematical/scientific reasoning, and birthweight in fish-consuming vs non-fish consuming mothers. These beneficial findings are similar to those observed in the Seychelles where fish consumption is high and prenatal Hg levels are x10 higher than US levels. Government recommendations should be reviewed to emphasise the beneficial value of fish consumption during pregnancy. DATA AVAILABILITY: ALSPAC data access is through a system of managed open access. The steps below highlight how to apply for access to the data included in this paper and all other ALSPAC data. If you have any questions about accessing data, please email: alspac-data@bristol.ac.uk.

There are few studies that chart the ways in which the religious beliefs and practices of parents and their offspring vary over time. Even fewer can relate this to aspects of their physical and mental health or distinguish the different facets of the environment that may have influenced the development or loss of religious/spiritual belief and behaviours over time. This paper describes the recent data collection in the Avon Longitudinal Study of Parents and Children (ALSPAC) on the beliefs and behaviours of the study parents some 27-28 years after the first measures were collected. Questions that were previously administered to the mother and her partner on religion, spirituality, behaviours, and beliefs (RSBB) were repeated for the fourth time, together with enhanced data on RSBB. The new data are described and compared with previous responses. The most notable difference between the 9 year and the 2020 sweep was the increase of professed non-believers in both the mothers (17.5% vs 29.8%) and partners (31.9% vs. 45.3%). As expected, on each occasion study partners were less likely to acknowledge RSBB compared to the study mothers. In the latest sweep, respondents were less likely to be unsure if they believed and more likely to not believe. Responses to “Do you believe in God or a divine power?” in mothers ranged from 49.9% stating ‘yes’ antenatally to 43.5% doing so in 2020; 14.9% vs 29.8% for ‘no’ and 35.2% to 26.6% for ‘not sure’. For partners, the corresponding figures are: ‘yes’ 37.0% vs. 30.0%; ‘no’ 28.6% vs. 45.3% and ‘not sure’ 34.5% vs. 24.6%. We plan to undertake detailed analyses of the antecedents and consequences of RBSS. All data are available for use by interested researchers.