Maternal prenatal paracetamol ingestion and scholastic attainments of the offspring.

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.

Quality of relationships in mothers and their partners in the Avon Longitudinal Study of Parents and Children.

Quality of relationship between partners is associated with a wide range of physical and psychological outcomes like anxiety and depression. There are relatively few longitudinal studies with detailed and repeated measures for quality of relationship, particularly in both partners. The Avon Longitudinal Study of Parents and Children (ALSPAC) is a large birth cohort study in the UK with five post-partum repeated measures of quality of relationship between mothers and their partners assessed using the Intimate Bond Measure (IBM). The Measure includes two subscales named "Care" and "Control". These were measured at 2.75, 6, 9, 12, and 18 years post-partum (baseline N for mothers: 8675; baseline N for partners: 5499). The aims of this data note are to provide a comprehensive overview on the existing IBM data in ALSPAC and to describe both its strengths and limitations for future users. The internal consistency of the subscales were high (Cronbach's alpha 0.95 and 0.88 for the Care and Control subscales) in both mothers and their partners at the baseline. In the Care subscale, all 12 items were highly correlated with the overall score (r>0.62) at the baseline, but in the Control subscale there were three items that had relatively low correlations with the total subscale (r<0.46). This should be taken into account in future research. The longitudinal nature of this data on both mothers and partners will enable detailed explorations of the causes and consequences of differences in quality of relationship.

A history of asthma may be associated with grandparents' exposures to stress and cigarette smoking.

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.

Associations between religious/spiritual beliefs and behaviours and dietary patterns: analysis of the parental generation in a prospective cohort study (ALSPAC) in Southwest England.

OBJECTIVE: Religious/spiritual beliefs and behaviours (RSBB) have been associated with health outcomes, with diet a potential mediator of this relationship. We therefore explored whether RSBB were associated with differences in diet. DESIGN: Dietary patterns and nutrient intakes were derived from food frequency questionnaire completed by pregnant women in 1991-1992 (mean age = 28·3 years, range = 15-46) and by the mothers and partners 4 years post-partum (mothers mean age = 32·3, range = 19-49; partners mean age = 34·5, range = 18-74). RSBB exposures measured in pregnancy included religious belief, affiliation and attendance. We first explored whether RSBBs were associated with dietary patterns in confounder-adjusted linear regression models. If associations were found, we examined whether RSBB were associated with nutrient intake (linear regression) and following nutrient intake guidelines (logistic regression). SETTING: Prospective birth cohort study in Southwest England (Avon Longitudinal Study of Parents and Children; ALSPAC). PARTICIPANTS: 13 689 enrolled mothers and their associated partners. RESULTS: In pregnant women, RSBB were associated with higher 'traditional' (i.e. 'meat and two veg') and lower 'vegetarian' dietary pattern scores. Religious attendance and non-Christian religious affiliation were associated with higher 'health-conscious' dietary pattern scores. Religious attendance was associated with increased micronutrient intake and following recommended micronutrient intake guidelines, with weaker effects for religious belief and affiliation. Comparable patterns were observed for mothers and partners 4 years post-partum, although associations between RSBB and nutrient intakes were weaker for partners. CONCLUSIONS: RSBBs are associated with broad dietary patterns and nutrient intake in this cohort. If these reflect causal relationships, diet may potentially mediate the pathway between RSBB and health.

Childhood life events of women enrolled in the Avon Longitudinal Study of Parents & Children (ALSPAC).

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.

Paternal health in the first 12-13 years of the ALSPAC study.

The Avon Longitudinal Study of Parents and Children (ALSPAC) collected information from the enrolled pregnancy onwards to identify features of the environment in which the study child was brought up. Among data collected were features concerning the health of the mothers' partners - generally the study father. This was an important feature since the father's physical and mental health can have a long-term effect on the family. In this Data Note we describe the data available on the father's health from pregnancy until 12 years after the offspring was born. Not only is this a valuable addition to the environmental information available for studies of the child's development and the mental health of the mother over time, but it will provide a useful description of the father himself during adulthood.

Associations between autistic traits and early ear and upper respiratory signs: a prospective observational study of the Avon Longitudinal Study of Parents and Children (ALSPAC) geographically defined childhood population.

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.

The beneficial role of personality in preserving well-being during the pandemic: A longitudinal population study.

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/demographic 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 frequency 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.

Gendered play behaviours in autistic and non-autistic children: A population-based cohort study.

LAY ABSTRACT: Non-autistic children tend to show gendered patterns of play behaviours - boys are more likely to play with 'masculine' toys, and girls are more likely to play with 'feminine' toys. However, little is known about whether autistic children follow these patterns as well. We looked at the masculinity and femininity of autistic and non-autistic children's play behaviours at multiple time points. Parents reported their children's play behaviours at ages 30, 42 and 57 months, and children reported their own play behaviours at 8 years old. We found no difference between autistic and non-autistic girls, who both showed more feminine play behaviours as they got older. Autistic boys' play behaviours were reported as less masculine than non-autistic boys at 42 and 57 months, and at 8 years old. We also found that non-autistic boys' play tended to become more masculine as they got older, but this was not the case for autistic boys. Our findings suggest that differences in autistic and non-autistic boys' play behaviours may develop at around 42 months old.

Maternal reports of morbidity during the index ALSPAC pregnancy.

Within the ALSPAC (Avon Longitudinal Study of Parents and Children) resource, information concerning the health of the mother during pregnancy is available from three sources: (i) computerised data collected by midwives after the delivery of the baby, known as the STORK database; (ii) data abstracted by ALSPAC staff from detailed medical obstetric records, and (iii) reports by mothers during pregnancy, and shortly after delivery using structured questionnaires completed at home. In this Data Note we focus on source (iii), and detail the information obtained from these mothers concerning their health, signs and symptoms together with medications and supplements taken during pregnancy. We also describe how the data can be accessed.

Maternal vitamin D during pregnancy and offspring autism and autism-associated traits: a prospective cohort study.

BACKGROUND: There has been a growing interest in the association between maternal levels of vitamin D during pregnancy and offspring autism. However, whether any associations reflect causal effects is still inconclusive. METHODS: We used data from a UK-based pregnancy cohort study (Avon Longitudinal Study of Parents and Children) comprising 7689 births between 1991 and 1992 with maternal blood vitamin D levels recorded during pregnancy and at least one recorded outcome measure, including autism diagnosis and autism-associated traits. The association between each outcome with seasonal and gestational age-adjusted maternal serum 25-hydroxyvitamin D during pregnancy was estimated using confounder-adjusted regression models. Multiple imputation was used to account for missing data, and restricted cubic splines were used to investigate nonlinear associations. Mendelian randomization was used to strengthen causal inference. RESULTS: No strong evidence of an association between maternal serum 25-hydroxyvitamin D during pregnancy and any offspring autism-associated outcome was found using multivariable regression analysis (autism diagnosis: adjusted OR = 0.98, 95% CI = 0.90-1.06), including with multiple imputation (autism diagnosis: adjusted OR = 0.99, 95% CI = 0.93-1.06), and no evidence of a causal effect was suggested by Mendelian randomization (autism diagnosis: causal OR = 1.08, 95% CI = 0.46-2.55). Some evidence of increased odds of autism-associated traits at lower levels of maternal serum 25-hydroxyvitamin D was found using spline analysis. LIMITATIONS: Our study was potentially limited by low power, particularly for diagnosed autism cases as an outcome. The cohort may not have captured the extreme lows of the distribution of serum 25-hydroxyvitamin D, and our analyses may have been biased by residual confounding and missing data. CONCLUSIONS: The present study found no strong evidence of a causal link between maternal vitamin D levels in pregnancy and offspring diagnosis or traits of autism.

The benefits of fish intake: Results concerning prenatal mercury exposure and child outcomes from the ALSPAC prebirth cohort.

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.

The importance of birth cohort studies to low and middle income countries.

In order to discern the causes of the health and developmental problems of children, and thence develop preventative strategies, longitudinal cohort studies offer major advantages. They can monitor the consequences of exposure to physical and psychological events and thence identify antecedents of various disorders. We describe the historical background to the development in the UK of this study design, and the uptake of longitudinal birth cohorts in low- and middle-income countries (LMICs), using the cohorts in Jamaica, South Africa and Brazil as exemplars. We describe the benefits of such studies and show how undertaking longitudinal cohort studies can have major health and financial benefits to the populations concerned. Additionally, the paper outlines the advantages of collaboration between studies and the pooling of data.

Paternal grandmother's smoking in pregnancy is associated with extreme aversion to bitter taste in their grandchildren.

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.

Grandmaternal smoking during pregnancy is associated with differential DNA methylation in peripheral blood of their grandchildren.

The idea that information can be transmitted to subsequent generation(s) by epigenetic means has been studied for decades but remains controversial in humans. Epidemiological studies have established that grandparental exposures are associated with health outcomes in their grandchildren, often with sex-specific effects; however, the mechanism of transmission is still unclear. We conducted Epigenome Wide Association Studies (EWAS) to test whether grandmaternal smoking during pregnancy is associated with altered DNA methylation (DNAm) in peripheral blood from their adolescent grandchildren. We used data from a birth cohort, with discovery and replication datasets of up to 1225 and 708 individuals (respectively, for the maternal line), aged 15-17 years, and tested replication in the same individuals at birth and 7 years. We show for the first time that DNAm at a small number of loci in cord blood is associated with grandmaternal smoking in humans. In adolescents we see suggestive associations in regions of the genome which we hypothesised a priori could be involved in transgenerational transmission - we observe sex-specific associations at two sites on the X chromosome and one in an imprinting control region. All are within transcription factor binding sites (TFBSs), and we observe enrichment for TFBS among the CpG sites with the strongest associations; however, there is limited evidence that the associations we see replicate between timepoints. The implication of this work is that effects of smoking during pregnancy may induce DNAm changes in later generations and that these changes are often sex-specific, in line with epidemiological associations.

Human transgenerational observations of regular smoking before puberty on fat mass in grandchildren and great-grandchildren.

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; (P1 = 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 (P1 = 0.050) at 17, and + 6.10 kg (P1 = 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.

Demographic and socioeconomic predictors of religious/spiritual beliefs and behaviours in a prospective cohort study (ALSPAC) in Southwest England: Results from the parental generation.

Background: We explored associations between possible demographic and socioeconomic causes of religious/spiritual beliefs and behaviours (RSBB) in the parental generation of the Avon Longitudinal Study of Parents and Children (ALSPAC). Methods : We used a prospective birth cohort study (ALSPAC) in Southwest England with 14,157 enrolled mothers and 14,154 associated partners. Three RSBB outcome measures collected during pregnancy were examined: religious belief (belief in God/a divine power; yes/not sure/no), religious affiliation (Christian/none/other) and religious attendance (frequency of attendance at a place of worship). Multiple demographic and socioeconomic exposures were assessed (23 in mothers and 22 in partners). We explored age-adjusted associations between each exposure and outcome using multinomial regression, in addition to exposure-age interactions. Results: Many demographic and socioeconomic factors were associated with RSBB, including age, ethnicity, marital status, education, income and deprivation. Overall, higher socioeconomic position was associated with increased levels of RSBB, particularly regarding religious attendance. For instance, compared to mothers with the lowest level of educational attainment, a degree-level education was associated with a six-fold increase in the relative risk ratio of religious attendance at least once a week, relative to not attending at all (RRR=5.90; 95% CI=[4.44; 7.86]). The magnitude of these associations often varied by outcome, e.g., income was associated with religious attendance, but only weakly with religious affiliation. Although results were demographically and socially patterned, overall effect sizes were relatively small, with a largest pseudo- R 2 value of 2.4%. Patterns of association were similar for mothers and partners. Conclusion: The observed positive association between socioeconomic position and RSBB is contrary to much previous theoretical and empirical work. Potential reasons for these differences are discussed, including cross-cultural variation in religiosity and state support, and differences between RSBB measures. This descriptive paper can also help inform future studies using these data regarding the consideration of appropriate confounders.

The Avon Longitudinal Study of Parents and Children (ALSPAC): a 2022 update on the enrolled sample of mothers and the associated baseline data.

The Avon Longitudinal Study of Parents and Children (ALSPAC) is a prospective birth cohort, based in and around Bristol, UK, established to explore genetic and environmental factors impacting health and development. 14,541 pregnancies were initially recruited from 20,248 eligible pregnancies. As the G1 (Generation-1) offspring turned 7 years of age, children from eligible pregnancies who had not been enrolled into the study were invited to take part. The enrolment status of these additional G1 offspring (n=913) has been well-documented. Here we provide an updated description of the ALSPAC G0 (Generation-0) mothers study cohort (which includes newly enrolled mothers), their associated pregnancies and the mz data file that defines this cohort. At the time of writing there are 14,833 unique mothers enrolled in ALSPAC, with 15,447 associated pregnancies enrolled. The update to the mz file also includes new variables to assist researchers when using mothers' data whilst accounting for non-independence between data related to multiple pregnancies (i.e., women with more than one pregnancy in the study).

The external housing environment of participants in the Avon Longitudinal Study of Parents and Children (ALSPAC): a resource for studies of influences on health.

Background: Early life environmental health exposures related to housing can have a significant impact on an individual's physical and mental health and physical development. Housing exposures can fall into two main areas - a representation of social circumstances and physical conditions. Methods: During pregnancy and post-delivery, self-completion questionnaires concerning the housing environment were administered to the ALSPAC (Avon Longitudinal Study of Parents & Children) study mothers and their partners until the study offspring were aged 18. Data collected included types of housing, housing tenure, numbers of rooms in the home, whether shared or sole use of kitchen and indoor flushing toilet, household moves, Council Tax band, difficulties in affording rent/mortgage and becoming homeless. Here we also describe the historic development of housing in the Bristol and surrounding Avon areas. Results: Data collected included the tenure (e.g., owned/rented) of the home, its size (indexed by the number of rooms), the presence of over-crowding (measured by the number of residents per room), presence of amenities, and frequency of household moves. This information was collected on over 13,000 women during pregnancy >8000 at age 10 and >4000 at 18 years. Council Tax bands were asked at 10 and 18 years. Conclusions: This is the first of two Data Notes on the housing type and housing circumstances of the families enrolled in ALSPAC. The second Data Note will detail their internal housing conditions. The data provides an excellent resource for researchers when considering the influences of housing on physical and mental health and development.