The Avon Longitudinal Study of Parents and Children (ALSPAC) is a transgenerational prospective observational study investigating influences on health and development across the life course. It considers multiple genetic, epigenetic, biological, psychological, social and other environmental exposures in relation to a similarly diverse range of health, social and developmental outcomes. Recruitment sought to enrol pregnant women in the Bristol area of the UK during 1990–92; this was extended to include additional children eligible using the original enrolment definition up to the age of 18 years. The children from 14 541 pregnancies were recruited in 1990–92, increasing to 15 247 pregnancies by the age of 18 years. This cohort profile describes the index children of these pregnancies. Follow-up includes 59 questionnaires (4 weeks–18 years of age) and 9 clinical assessment visits (7–17 years of age). The resource comprises a wide range of phenotypic and environmental measures in addition to biological samples, genetic (DNA on 11 343 children, genome-wide data on 8365 children, complete genome sequencing on 2000 children) and epigenetic (methylation sampling on 1000 children) information and linkage to health and administrative records. Data access is described in this article and is currently set up as a supported access resource. To date, over 700 peer-reviewed articles have been published using ALSPAC data.

Summary The Avon Longitudinal Study of Children and Parents (ALSPAC) was established to understand how genetic and environmental characteristics influence health and development in parents and children. All pregnant women resident in a defined area in the South West of England, with an expected date of delivery between 1st April 1991 and 31st December 1992, were eligible and 13 761 women (contributing 13 867 pregnancies) were recruited. These women have been followed over the last 19–22 years and have completed up to 20 questionnaires, have had detailed data abstracted from their medical records and have information on any cancer diagnoses and deaths through record linkage. A follow-up assessment was completed 17–18 years postnatal at which anthropometry, blood pressure, fat, lean and bone mass and carotid intima media thickness were assessed, and a fasting blood sample taken. The second follow-up clinic, which additionally measures cognitive function, physical capability, physical activity (with accelerometer) and wrist bone architecture, is underway and two further assessments with similar measurements will take place over the next 5 years. There is a detailed biobank that includes DNA, with genome-wide data available on >10 000, stored serum and plasma taken repeatedly since pregnancy and other samples; a wide range of data on completed biospecimen assays are available. Details of how to access these data are provided in this cohort profile.

Background & AimsNarrative reviews of paediatric NAFLD quote prevalences in the general population that range from 9% to 37%; however, no systematic review of the prevalence of NAFLD in children/adolescents has been conducted. We aimed to estimate prevalence of non-alcoholic fatty liver disease (NAFLD) in young people and to determine whether this varies by BMI category, gender, age, diagnostic method, geographical region and study sample size.MethodsWe conducted a systematic review and meta-analysis of all studies reporting a prevalence of NAFLD based on any diagnostic method in participants 1–19 years old, regardless of whether assessing NAFLD prevalence was the main aim of the study.ResultsThe pooled mean prevalence of NAFLD in children from general population studies was 7.6% (95%CI: 5.5% to 10.3%) and 34.2% (95% CI: 27.8% to 41.2%) in studies based on child obesity clinics. In both populations there was marked heterogeneity between studies (I2 = 98%). There was evidence that prevalence was generally higher in males compared with females and increased incrementally with greater BMI. There was evidence for differences between regions in clinical population studies, with estimated prevalence being highest in Asia. There was no evidence that prevalence changed over time. Prevalence estimates in studies of children/adolescents attending obesity clinics and in obese children/adolescents from the general population were substantially lower when elevated alanine aminotransferase (ALT) was used to assess NAFLD compared with biopsies, ultrasound scan (USS) or magnetic resonance imaging (MRI).ConclusionsOur review suggests the prevalence of NAFLD in young people is high, particularly in those who are obese and in males.

Background We aimed to examine the association of gestational weight gain (GWG) and pre-pregnancy weight with offspring adiposity and cardiovascular risk factors. Methods and results Data from 5,154 (for adiposity and blood pressure) and 3,457 (for blood assays) mother-offspring pairs from a UK prospective pregnancy cohort were used. Random effects multilevel models were used to assess incremental GWG (median and range of repeat weight measures per woman: 10 (1, 17)). Women who exceeded the 2009 Institute of Medicine recommended GWG were more likely to have offspring with greater body mass index, waist, fat mass, leptin, systolic blood pressure, CRP and IL-6 levels, and lower HDLc and Apolipoprotein A1 levels. Children of women who gained less than the recommended amounts had lower levels of adiposity, but other cardiovascular risk factor tended to be similar in this group to offspring of women gaining recommended amounts. When examined in more detail greater pre-pregnancy weight was associated with greater offspring adiposity and more adverse cardiovascular risk factors at age 9. GWG in early pregnancy (0 to 14 weeks) was positively associated with offspring adiposity across the entire distribution, but strengthened in women gaining more than 500g/week. By contrast, between 14 and 36 weeks GWG was only associated with offspring adiposity in women gaining at least 500g/week. GWG between 14-36 weeks was positively and linearly associated with adverse lipid and inflammatory profiles with these associations largely mediated by the associations with offspring adiposity. Conclusions Greater maternal pre-pregnancy weight and GWG up to 36 weeks gestation are associated with greater offspring adiposity and adverse cardiovascular risk factors. Before implementing any GWG recommendations, the balance of risks and benefits of attempts to control GWG for short- and long-term outcomes in mother and child should be ascertained.

Background The nature and contribution of different pregnancy related complications to future cardiovascular disease (CVD) and its risk factors, as well as mechanisms underlying these associations remain unclear. Methods and Results We studied associations of pregnancy diabetes, hypertensive disorders of pregnancy (HDP), preterm delivery and size for gestational age with calculated 10 year CVD risk (based on the Framingham score) and a wide range of cardiovascular risk factors measured 18 years after pregnancy (mean age at outcome assessment: 48 years) in a prospective cohort of 3,416 women. Gestational diabetes (GDM) was positively associated with fasting glucose and insulin, even after adjusting for potential confounders whilst HDP were associated with BMI, waist circumference, blood pressure, lipids and insulin. Large for gestational age (LGA) was associated with greater waist circumference and glucose concentrations, whilst small for gestational age (SGA) and preterm delivery were associated with higher blood pressure. The association with the calculated 10 year CVD risk based on the Framingham prediction score was OR=1.31 (95%CI: 1.11, 1.53) for preeclampsia and 1.26 (0.95, 1.68) for GDM compared to women without preeclampsia and GDM respectively. Conclusions HDP and pregnancy diabetes are independently associated with an increased calculated 10 year CVD risk. Preeclampsia may be the better predictor of future CVD since it was associated with a wider range of cardiovascular risk factors. Our results suggest that pregnancy may be an important opportunity for early identification of women at increased risk of CVD later in life.

Growing evidence indicates that women with a history of common pregnancy complications, including fetal growth restriction and preterm delivery (often combined as low birth weight), hypertensive disorders of pregnancy, and gestational diabetes, are at increased risk for cardiovascular disease later in life. The purpose of this paper was to review the associations of parity and these 4 pregnancy complications with cardiovascular morbidity and mortality; to review the role of cardiovascular risk factors before, during, and after pregnancy complications in explaining these associations; and to explore the implications of this emerging science for new research and policy. We systematically searched for relevant cohort and case-control studies in Medline through December 2012 and used citation searches for already published reviews to identify new studies. The findings of this review suggest consistent and often strong associations of pregnancy complications with latent and future cardiovascular disease. Many pregnancy complications appear to be preceded by subclinical vascular and metabolic dysfunction, suggesting that the complications may be useful markers of latent high-risk cardiovascular trajectories. With further replication research, these findings would support the utility of these prevalent pregnancy complications in identifying high-risk women for screening, prevention, and treatment of cardiovascular disease, the leading cause of morbidity and mortality among women.

Background & aims-Non-alcoholic fatty liver disease (NAFLD) is a common cause of liver disease in children and adolescents. The majority of studies of NAFLD in children have been in select populations of the clinically obese. Study aims were to estimate the prevalence of elevated alanineaminotransferase (ALT, as a marker of NAFLD) in a general contemporary adolescent population and to identify leading risk factors for ALT elevation (> 30 U/L). Conclusions-ALT is associated with waist circumference and insulin resistance even in a young population. These characteristics could be utilized to identify adolescents who may benefit from screening for NAFLD, offering an opportunity to prevent disease progression at an early age. Methods-We

Background: Evidence suggests that in utero exposure to undernutrition and overnutrition might affect adiposity in later life. Epigenetic modification is suggested as a plausible mediating mechanism.Methods: We used multivariable linear regression and a negative control design to examine offspring epigenome-wide DNA methylation in relation to maternal and offspring adiposity in 1018 participants.Results: Compared with neonatal offspring of normal weight mothers, 28 and 1621 CpG sites were differentially methylated in offspring of obese and underweight mothers, respectively [false discovert rate (FDR)-corrected P-value < 0.05), with no overlap in the sites that maternal obesity and underweight relate to. A positive association, where higher methylation is associated with a body mass index (BMI) outside the normal range, was seen at 78.6% of the sites associated with obesity and 87.9% of the sites associated with underweight. Associations of maternal obesity with offspring methylation were stronger than associations of paternal obesity, supporting an intrauterine mechanism. There were no consistent associations of gestational weight gain with offspring DNA methylation. In general, sites that were hypermethylated in association with maternal obesity or hypomethylated in association with maternal underweight tended to be positively associated with offspring adiposity, and sites hypomethylated in association with maternal obesity or hypermethylated in association with maternal underweight tended to be inversely associated with offspring adiposity.Conclusions: Our data suggest that both maternal obesity and, to a larger degree, underweight affect the neonatal epigenome via an intrauterine mechanism, but weight gain during pregnancy has little effect. We found some evidence that associations of maternal underweight with lower offspring adiposity and maternal obesity with greater offspring adiposity may be mediated via increased DNA methylation.