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There is now a growing interest in early-life influences on adult diseases in China. A number of birth cohorts have been established. This systematic review provided a better understanding of the development of mother–baby cohorts in China. Systematic review. We conducted a systematic review for research or profile papers in English/Chinese that reported data from mother–baby cohorts in mainland China, with ≥1y follow-up after birth. We identified 315 papers, corresponding to 31 cohorts from 19 provinces/megacities. All cohorts started in 1999–2017 (21 after 2010) and were set up with broad objectives or specific scientific focus. The baseline sample size varied, from <500 to >300,000 mothers. A majority of cohorts were initiated during pregnancy and followed children to <10y, only six to adolescence and none into adulthood. These cohorts mostly collected samples from mothers and babies, in addition to using interviews/questionnaires to collect information about pregnancy, birth and child health. Most cohorts were recruited from a single province/city. The large western region was understudied. Mother–baby cohorts have developed rapidly in China, but usually with a short follow-up duration. Extending the follow-up of children and developing cross-cohort collaboration will increase the diversity, size and coverage of the sample, allow studying early influences on life-course health and identify targets for early intervention in the Chinese population. [ABSTRACT FROM AUTHOR]

Background: Evaluating the effectiveness of early years parenting interventions provides evidence to improve the development and wellbeing of children. This protocol paper describes a study to explore the feasibility of evaluating the Incredible Years Toddler early life intervention programme, which is offered to parents of 1–3-year-olds via the Better Start Bradford programme. The study aims to use a Trial within a Cohort Study (TwiCS) design that randomly selects individuals participating in a cohort to be offered an intervention. The TwiCS information and consent process is person-centred and aims to replicate real-world practice whereby only those who are offered the intervention are given information about the intervention. The cohort is the Born in Bradford's Better Start (BiBBS) cohort, an interventional birth cohort recruiting expectant parents in three areas of Bradford, UK. The study will assess the feasibility of TwiCS procedures, staged consent, and intervention take-up. Methods: We will conduct a feasibility TwiCS to test study procedures. We aim to establish the following: (1) whether TwiCS methodology can be implemented to create control and intervention arms, whilst documenting any incidences of contamination within the cohort; (2) whether satisfactory rates of intervention uptake are achieved among participants allocated to the intervention; and (3) whether satisfactory rates of retention of participants in the intervention can be achieved. A Red Amber Green (RAG) rating system has been applied to support the feasibility assessment of each objective: to be rated red (not achieved), amber (partly achieved), and green (achieved). Eligible participants in the BiBBS cohort will be individually randomised 1:1 to the intervention or control arms, with stratification by child age (1 or 2 years old at the time of randomisation) and ethnicity (White British, South Asian, or other). BiBBS researchers will seek consent from participants randomised to the intervention to pass their contact details onto Incredible Years' delivery agents. Discussion: This feasibility study will inform the utility of the TwiCs approach within an experimental birth cohort to evaluate interventions for infants, toddlers, and their families. Trial registration: The study was prospectively registered on ISRCTN (ISRCTN16150114). [ABSTRACT FROM AUTHOR]

Background: Although age is the biggest known risk factor for dementia, there remains uncertainty about other factors over the life course that contribute to a person's risk for cognitive decline later in life. Furthermore, the pathological processes leading to dementia are not fully understood. The main goals of Insight 46—a multi-phase longitudinal observational study—are to collect detailed cognitive, neurological, physical, cardiovascular, and sensory data; to combine those data with genetic and life-course information collected from the MRC National Survey of Health and Development (NSHD; 1946 British birth cohort); and thereby contribute to a better understanding of healthy ageing and dementia. Methods/Design: Phase 1 of Insight 46 (2015–2018) involved the recruitment of 502 members of the NSHD (median age = 70.7 years; 49% female) and has been described in detail by Lane and Parker et al. 2017. The present paper describes phase 2 (2018–2021) and phase 3 (2021–ongoing). Of the 502 phase 1 study members who were invited to a phase 2 research visit, 413 were willing to return for a clinic visit in London and 29 participated in a remote research assessment due to COVID-19 restrictions. Phase 3 aims to recruit 250 study members who previously participated in both phases 1 and 2 of Insight 46 (providing a third data time point) and 500 additional members of the NSHD who have not previously participated in Insight 46. Discussion: The NSHD is the oldest and longest continuously running British birth cohort. Members of the NSHD are now at a critical point in their lives for us to investigate successful ageing and key age-related brain morbidities. Data collected from Insight 46 have the potential to greatly contribute to and impact the field of healthy ageing and dementia by combining unique life course data with longitudinal multiparametric clinical, imaging, and biomarker measurements. Further protocol enhancements are planned, including in-home sleep measurements and the engagement of participants through remote online cognitive testing. Data collected are and will continue to be made available to the scientific community. [ABSTRACT FROM AUTHOR]

In a large-scale environmental health population study that is composed of subprojects, often different fractions of participants out of the total enrolled have measures of specific outcomes. It's conceptually reasonable to assume the association study would benefit from utilizing additional exposure information from those with a specific outcome not measured. Partial least squares regression is a practical approach to determine the exposure-outcome associations for mixture data. Like a typical regression approach, however, the partial least squares regression requires that each data observation must have both complete covariate and outcome for model fitting. In this paper, we propose novel adjustments to the general partial least squares regression to estimate and examine the association effects of individual environmental exposure to an outcome within a more complete context of the study population's environmental mixture exposures. The proposed framework takes advantage of the bilinear model structure. It allows information from all participants, with or without the outcome values, to contribute to the model fitting and the assessment of association effects. Using this proposed framework, incorporation of additional information will lead to smaller root mean square errors in the estimation of association effects, and improve the ability to assess the significance of the effects. [ABSTRACT FROM AUTHOR]

This paper aims to provide a comprehensive overview of piloting approaches, systemize piloting processes, and underline good practices in large scale longitudinal birth cohort studies. We identified 54 eligible studies, and by applying predefined inclusion criteria, we included 10 studies in the systematic review. The main findings are that the longitudinal birth cohort surveys most often include all three types of pilots in every sweep—pre-test, instruments pilot and dress rehearsal. Sampling procedures and sample sizes in pilots vary a lot depending on the type and aims of a pilot, and from sweep to sweep. The reporting on piloting and its key findings is regularly present in longitudinal birth cohort studies, especially for instruments pilots and dress rehearsals, while it is less common for pre-tests. Based on the findings, the recommendations for other researchers are to adopt the same terms for different types of pilots—pre-pilots, instruments pilots and dress rehearsals, to extend and uniform reports on piloting, to report information about pilots' response and attrition rates, and to dedicate a separate chapter to piloting in survey general technical report. [ABSTRACT FROM AUTHOR]

Background: As a key indicator to measure the mental health status, psychological security level of Chinese college students and its changes over time are of great value to examine.Methods: A cross-temporal meta-analysis was performed using papers that measured the psychological security level of Chinese college students using the Security Questionnaire between 2006 and 2019. In addition, a time lag analysis was conducted to define whether the selected macro social indicators can explain the changes in the psychological security level.Results: A total of 58 papers involving 28,352 Chinese college students were included in the final sample. The results revealed that scores of psychological security and its two factors were significantly negatively correlated with the year. Scores of psychological security and its two factors were significantly associated with five social indicators of economic condition (residents' consumption level), social connectedness (divorce rate, urbanization level) and overall threat (college enrollment rate, crime rate), suggesting that social change may account for the decline in psychological security level of Chinese college students.Limitations: The underlying mechanism is only discussed at a theoretical level. Thus, future studies can collect the relating empirical evidence to test the proposed theoretical model.Conclusions: Our study revealed a decreasing trend of Chinese college students' psychological security level across time, which was associated with macro-social changes in diverse areas. In addition, combined with the corresponding macro-social indicators, a three-dimensional theoretical framework is proposed to explain the psychological security for college students as a group. [ABSTRACT FROM AUTHOR]

Background: Large birth cohort studies are extremely valuable in assessing associations between early life exposures and long-term outcomes. Establishing new birth cohorts is challenging due to declining participation rates. Online methods of data collection may increase feasibility, but have not been evaluated thoroughly.Objective: The primary objective of the ongoing PRegnancy and Infant DEvelopment (PRIDE) Study is to identify exposures during pregnancy and in early life that may affect short-term or long-term health of mother and/or child. In this manuscript, we aimed to evaluate methods of recruitment and online data collection applied.Population: Dutch women aged ≥18 years in early pregnancy.Design: Prospective cohort study.Methods: Initially, only prenatal care providers recruited participants, but alternative recruitment methods were added as a result of disappointing participation rates, including collaboration with "Moeders voor Moeders" (organisation that visits women in early pregnancy) and Facebook advertisements. Data on demographic characteristics, obstetric history, maternal health, life style factors, occupational exposures, nutrition, pregnancy complications, and infant outcomes are primarily collected through Web-based questionnaires at multiple time points during and after pregnancy. Additional data collection components include paternal questionnaires, blood and saliva sampling, and linkage to medical records.Preliminary Results: By September 2019, 9573 women were included in the PRIDE Study, of which 1.3% completed paper-based questionnaires. Mean age of the women analysed was 30.6 years, 71.1% had a high level of education, 57.2% were primiparae, and mean gestational age at enrolment was 9.9 (range 3, 37) weeks, with slight differences between recruitment methods. Pregnancy outcome was known for 89.8%. Retention rate at 6 months after the estimated date of delivery was estimated at 70%. Multiple validation studies conducted within the PRIDE Study indicated high data quality.Conclusion(s): Although challenging and time-consuming, online methods for recruitment and data collection may enable the establishment of new birth cohort studies. [ABSTRACT FROM AUTHOR]

Background: Bisphenol A (BPA) is an industrial chemical mostly used in the manufacture of plastics, resins and thermal paper. Several studies have reported adverse health effects with BPA exposures, namely metabolic disorders and altered neurodevelopment in children, among others. The aim of this study was to explore BPA exposure, its socio-demographic and life-style related determinants, and its association with neurodevelopmental outcomes in early school age children from Poland.Methods: A total of 250 urine samples of 7 year-old children from the Polish Mother and Child Cohort Study (REPRO_PL) were analyzed for BPA concentrations using high performance liquid chromatography with online sample clean-up coupled to tandem mass spectrometry (online-SPE-LC-MS/MS). Socio-demographic and lifestyle-related data was collected by questionnaires or additional biomarker measurements. Emotional and behavioral symptoms in children were assessed using mother-reported Strengths and Difficulties Questionnaire (SDQ). Cognitive and psychomotor development was evaluated by Polish adaptation of the Intelligence and Development Scales (IDS) performed by trained psychologists.Results: Urinary BPA concentrations and back-calculated daily intakes (medians of 1.8 μg/l and 46.3 ng/kg bw/day, respectively) were similar to other European studies. Urinary cotinine levels and body mass index, together with maternal educational level and socio-economic status, were the main determinants of BPA levels in Polish children. After adjusting for confounding factors, BPA has been found to be positively associated with emotional symptoms (β: 0.14, 95% CI: 0.022; 0.27). Cognitive and psychomotor development were not found to be related to BPA levels.Conclusions: This study represents the first report of BPA levels and their determinants in school age children in Poland. The exposure level was found to be related to child emotional condition, which can have long-term consequences including social functioning and scholastic achievements. Further monitoring of this population in terms of overall chemical exposure is required. [ABSTRACT FROM AUTHOR]

The relationship between the socio-economic status of parents and children is referred to by the literature as intergenerational social mobility. Low mobility implies that human capital, skills and talent can be misallocated. As a consequence, the workers’ efforts, their motivation and productivity could be negatively affected, causing adverse effects on economy growth and competitiveness. This paper attempts to study the evolution of intergenerational social mobility before and during the recent economic crisis in Spain. The methodology applied consists in analysing the movements along the occupational scale of children with respect to their parents. This involves associating the National Classification of Occupations with the New International Socio-economic Index of Occupational Status. Statistic and econometric methods are used to assess these occupational transitions and to analyse the covariates’ effects on them. Data used corresponds to the 2005 and 2011 Living Condition Survey (INE 2005, 2011). [ABSTRACT FROM AUTHOR]

Aim: In Hungary, almost all mothers, depending on their previous employment status, were supported at 70% of their previous income through 2 years postpartum. This paper investigates the impact of postnatal employment, between the birth and 6 months, on breastfeeding through 6 months of age. Methods: Analysis was based on responses from 7756 mothers of children aged 5 to 7 months, who participated in the first two waves of the longitudinal study 'Cohort '18 - Growing Up in Hungary'. When examining the association between employment and breastfeeding, confounding variables were justified based on theoretical foundations, visualised by a directed acyclic graph. Key findings: Overall, 3.4% of the mothers had already gone back to work; 50% of the children were being breastfed, with 34.6% partially and 15.4% exclusively. For the groups of mothers with basic or tertiary education, employment activity was not related to breastfeeding rates, even when confounding factors were controlled. Among mothers with secondary education, lower multivariable odds of exclusive breastfeeding (OR = 0.27, 95% CI = 0.09, 0.79) were observed where they were in active employment. Conclusion: Further studies are needed to investigate the education-specific association between labour market reintegration and breastfeeding, in order to inform policy. [ABSTRACT FROM AUTHOR]

Te Kupenga 2018 was a representative survey of Māori adults in Aotearoa (New Zealand), with a focus on culture and wellbeing, as well as language. In this paper, new estimates from Te Kupenga are reported, including the numbers of first and second language speakers of te reo Māori (the Māori language). Large proportions of both first and second language speakers reported learning te reo Māori from family and community interactions, as well as through Māori-medium education. Comparisons of three generations of adult Māori provide evidence of a resurgence in te reo Māori, with the youngest generation accounting for a majority of first language speakers and almost half of more proficient speakers. Differences between first and second language speakers in terms of proficiency, language learning and usage are significant, and need to be taken into account in the study of the revitalisation of Māori and of other languages. [ABSTRACT FROM AUTHOR]

This paper aimed to examine the effect of breastfeeding on longitudinal patterns of common infections up to 2 years and respiratory symptoms up to 8 years. To assess the incidence and reoccurrence of infections and allergic symptoms in the first years of life among 1,603 children from the EDEN mother–child cohort, distinct longitudinal patterns of infectious diseases as well as skin rash and respiratory symptoms were identified by group‐based trajectory modelling. To characterize infections, we considered the parent‐reported number of cold/nasopharyngitis and diarrhoea from birth to 12 months and otitis and bronchitis/bronchiolitis from birth to 2 years. To characterize allergy‐related symptoms, we considered the parent‐reported occurrence of wheezing and skin rash from 8 months to 8 years and asthma from 2 to 8 years. Then associations between breastfeeding and these longitudinal patterns were assessed through adjusted multinomial logistic regression. Compared with never‐breastfed infants, ever‐breastfed infants were at a lower risk of diarrhoea events in early infancy as well as infrequent events of bronchitis/bronchiolitis throughout infancy. Only predominant breastfeeding duration was related to frequent events of bronchitis/bronchiolitis and infrequent events of otitis. We found no significant protective effect of breastfeeding on longitudinal patterns of cold/nasopharyngitis, skin rash, or respiratory symptoms. For an infant population with a short breastfeeding duration, on average, our study confirmed a protective effect of breastfeeding on diarrhoea events in early infancy, infrequent bronchitis/bronchiolitis and, to a lesser extent, infrequent otitis events up to 2 years but not on other infections, skin rash, or respiratory symptoms4. In an infant population with a short breastfeeding duration and using longitudinal patterns of infection, skin rash and respiratory symptoms, on average, our study confirmed a protective effect of breastfeeding on diarrhea events in early infancy, infrequent bronchitis/bronchiolitis and, to a lesser extent,infrequent otitis events up to 2 years but not on cold/ nasopharyngitis, skin rash or respiratory symptoms. [ABSTRACT FROM AUTHOR]

Objective This research aims to identify predictors of attrition in a longitudinal birth cohort study in Australia and assess differences in baseline characteristics and responses in subsequent follow-up phases between contactable non-responders and uncontactable non-responders deemed 'lost to follow-up (LTF)'. Methods 3368 women recruited from three public hospitals in Southeast Queensland and Northern New South Wales during antenatal visits in 2006-2011 completed a baseline questionnaire to elicit information on multiple domains of exposures. A follow-up questionnaire was posted to each participant at 1 year after birth to obtain mother's and child's health and development information. Multivariate logistic regression was used to model the association between exposures and respondents' status at 1 year. The effect of an inverse-probability-weighting method to adjust for non-response was studied. Results Overall attrition at 1-year was 35.4 %; major types of attrition were 'contactable non-response' (27.6 %) and 'LTF' (6.7 %). These two attrition types showed different responses at the 3-year follow-up and involved different predictors. Besides shared predictors (first language not English, higher risk of psychological distress, had smoked during pregnancy, higher levels of family conflict), distinguishable predictors of contactable non-responders were younger age, having moved home in the past year and having children under 16 in the household. Attrition rates increased substantially from 20 % in 2006 to 54 % in 2011. Conclusions This observed trend of increased attrition rates raises concern about the use of traditional techniques, such as 'paper-based' questionnaires, in longitudinal cohort studies. The supplementary use of electronic communications, such as online survey tools and smart-device applications, could provide a better alternative. [ABSTRACT FROM AUTHOR]

Purpose: This study examines the association between mental health problems in adolescence and general practice (GP) costs during adulthood up to age 50 in the UK. Methods: We conducted secondary analyses of three British birth cohorts (individuals born in single weeks in 1946, 1958 and 1970). Data for the three cohorts were analysed separately. All respondents who participated in the cohort studies were included. Adolescent mental health status was assessed in each cohort using the Rutter scale (or, for one cohort, a forerunner of that scale) completed in interviews with parents and teachers when cohort members were aged around 16. Presence and severity of conduct and emotional problems were modelled as independent variables in two-part regression models in which the dependent variable was costs of GP services from data collection sweeps up to mid-adulthood. All analyses were adjusted for covariates (cognitive ability, mother's education, housing tenure, father's social class and childhood physical disability). Results: Adolescent conduct and emotional problems, particularly when coexisting, were associated with relatively high GP costs in adulthood up to age 50. Associations were generally stronger in females than males. Conclusion: Associations between adolescent mental health problems and annual GP cost were evident decades later, to age 50, suggesting that there could be significant future savings to healthcare budgets if rates of adolescent conduct and emotional problems could be reduced. Trial registration: Not applicable. [ABSTRACT FROM AUTHOR]

A mother's nutritional choices while pregnant may have a great influence on her baby's development in the womb and during infancy. There is evidence that what a mother eats during pregnancy interacts with her genes to affect her child's susceptibility to poor health outcomes including childhood obesity, pre-diabetes, allergy and asthma. Furthermore, after what an infant eats can change his or her intestinal bacteria, which can further influence the development of these poor outcomes. In the present paper, we review the importance of birth cohorts, the formation and early findings from a multi-ethnic birth cohort alliance in Canada and summarise our future research directions for this birth cohort alliance. We summarise a method for harmonising collection and analysis of self-reported dietary data across multiple cohorts and provide examples of how this birth cohort alliance has contributed to our understanding of gestational diabetes risk; ethnic and diet-influences differences in the healthy infant microbiome; and the interplay between diet, ethnicity and birth weight. Ongoing work in this birth cohort alliance will focus on the use of metabolomic profiling to measure dietary intake, discovery of unique diet-gene and diet-epigenome interactions, and qualitative interviews with families of children at risk of metabolic syndrome. Our findings to-date and future areas of research will advance the evidence base that informs dietary guidelines in pregnancy, infancy and childhood, and will be relevant to diverse and high-risk populations of Canada and other high-income countries. [ABSTRACT FROM AUTHOR]

The paper estimates the probability of living until the age of a grandparent and a great-grandparent in different cohorts of Estonian population. The objects of comparison are men and women born in 1939, 1959, 1989 and nowadays (2016). It turned out that (assuming the stability of demographic behaviour) people born in 1989 have the highest probability to see the grandchildren and also great-grandchildren. In the case of people born in 21st century, the probability is going down in spite of increasing life expectancy. The reason for this feature is massive postponing of family creation. [ABSTRACT FROM AUTHOR]

Abstract: The objectives of this study were to estimate the age of complementary feeding introduction (CFI) and investigate the related health, demographic, and socio‐economic factors. Analyses were based on 10,931 infants from the French national birth cohort ELFE, born in 2011. Health, demographic, and socio‐economic data concerning infants and parents were collected at birth (face‐to‐face interviews and medical records) and 2 months (telephone interviews). Data on milk feeding and CFI practices were collected at birth and 2 months then monthly from 3 to 10 months using online or paper questionnaires. The associations between both health and social factors and CFI age were tested by multivariable multinomial logistic regressions. The mean CFI age was 5.2 ± 1.2 months; 26% of the infants started complementary feeding before 4 months of age (CF < 4 months), 62% between 4 and 6 months of age, and 12% after 6 months of age (CF > 6 months). CF < 4 months was more likely when mothers smoked, were overweight/obese, younger (<29 years), and used their personal experience as an information source in child caregiving and when both parents were not born in France. CF < 4 months was less likely when the infant was a girl, second‐born, when the mother breastfed longer, and had attended at least one birth preparation class. Mothers of second‐born infants and who breastfed their child longer were more likely to introduce CF > 6 months. Couples in which fathers were born in France and mothers were not born in France were less likely to introduce CF > 6 months. CF < 4 months occurred in more than 25% of the cases. It is important to continue promoting clear CFI recommendations, especially in smoking, overweight, young, not born in France, and nonbreastfeeding mothers. [ABSTRACT FROM AUTHOR]

Breastfeeding is recommended until 6 months of age, but a wide range of infant formula is available for nonbreastfed or partially breastfed infants. Our aim was to describe infant formula selection and to examine social- and health-related factors associated with this selection. Analyses were based on 13,291 infants from the French national birth cohort Etude Longitudinale Française depuis l'Enfance. Infant diet was assessed at Month 2 by phone interview and monthly from Months 3 to 10 via internet/paper questionnaires. Infant formulas were categorized in 6 groups: extensively or partially hydrolysed, regular with or without prebiotics/probiotics, and thickened with or without prebiotics/probiotics. Associations between type of infant formula used at 2 months and family or infant characteristics were assessed by multinomial logistic regressions. At Month 2, 58.1% of formula-fed infants were fed with formula enriched in prebiotics/probiotics, 31.5% with thickened formula, and 1.4% with extensively hydrolysed formula. The proportion of formula-fed infants increased regularly, but the type of infant formula used was fairly stable between 2 and 10 months. At Month 2, extensively hydrolysed formulas were more likely to be used in infants with diarrhoea or regurgitation problems. Partially hydrolysed formulas were more often used in families with high income, with a history of allergy, or with infants with regurgitation issues. Thickened formulas were used more with boys, preterm infants, infants with regurgitation issues, or in cases of early maternal return to work. The main factors related to the selection of infant formula were family and infant health-related ones. [ABSTRACT FROM AUTHOR]

Colorectal cancer (CRC) epidemiology is changing due to a birth cohort effect, first recognized by increasing incidence of early onset CRC (EOCRC, age <50 years). In this paper, we define "birth cohort CRC" as the observed phenomenon, among individuals born 1960 and later, of increasing CRC risk across successive birth cohorts, rising EOCRC incidence, increasing incidence among individuals aged 50 to 54 years, and flattening of prior decreasing incidence among individuals aged 55 to 74 years. We demonstrate birth cohort CRC is associated with unique features, including increasing rectal cancer (greater than colon) and distant (greater than local) stage CRC diagnosis, and increasing EOCRC across all racial/ethnic groups. We review potential risk factors, etiologies, and mechanisms for birth cohort CRC, using EOCRC as a starting point and describing importance of viewing these through the lens of birth cohort. We also outline implications of birth cohort CRC for epidemiologic and translational research, as well as current clinical practice. We postulate that recognition of birth cohort CRC as an entity—including and extending beyond rising EOCRC—can advance understanding of risk factors, etiologies, and mechanisms, and address the public health consequences of changing CRC epidemiology. [Display omitted] [ABSTRACT FROM AUTHOR]

The Finnish Birth Cohort 1987 grew up during the recession that hit Finland in the early 1990s, which had an impact on their parents' activity in the labour market. In this paper we use Finnish register data to build employment and education sequences for all young people born in Finland in 1987 for the period 2005-2012 and employment sequences for all their parents for the entire length of their children's lives from 1987 until 2012. The sequences were analysed and clustered, and four multinomial logistic regression models were used to find how parents' trajectories connect to their children's early adulthood trajectories. Most parents had been on a stable employment trajectory, but we found mothers and fathers who were absent from the labour market during the recession of the 1990s and after it - and some parents never entirely returned to work during this 1987-2012 follow-up. Likewise, most children were either on an employment or education trajectory, but we found groups of children who were on very early child care trajectories, unemployment trajectories, or on a trajectory with no records in the Finnish registers, which in the Finnish context implies that those young people are not employed, not in education and not receiving any of the various benefits. Disadvantageous trajectories were mostly very lasting. We found strong connections between parents' disadvantages in the labour market and children's disadvantageous early adulthood trajectories, even when adjusting for strong background variables. The strongest connections arise from parents' long absences from the labour market. [ABSTRACT FROM AUTHOR]

Background: The relationship between parental age at pregnancy and offspring development in low- and middle-income countries remains unclear. We aimed to examine the associations of parental age at pregnancy with adolescent development in rural China. Methods: We conducted a prospective birth cohort study of offspring born to pregnant women who participated in an antenatal micronutrient supplementation trial in rural Western China. Adolescent cognitive development and emotional and behavioural problems were assessed by using the Wechsler Intelligence Scale for Children-IV and the Youth Self-Report-2001, respectively. After accounting for the possible nonlinear relationships, we examined the linear associations between parental age (in years) at pregnancy and scores of adolescent cognitive development and emotional and behavioural problems by performing generalized estimating equations. Results: Among 1897 adolescents followed from birth to early adolescence, 59.5% were male with a mean age of 11.8 (standard deviation (SD): 0.8) years. The mean ages of mothers and fathers at pregnancy were 24.6 (SD: 4.4) and 27.9 (SD: 4.1) years old, respectively. All the P values of the nonlinear terms between parental age and adolescent development in all domains were greater than 0.05. Each one-year increase in maternal age at pregnancy was associated with a 0.29-point (95% confidence interval (CI) 0.06, 0.52) increase in the full-scale intelligence quotient in early adolescence. After parental age was categorized into quartiles, the total behavioural problem scores of adolescents with fathers with an age in the fourth quartile (Q4) were 6.71 (95% CI 0.86, 12.57) points higher than those of adolescents with fathers with an age in the first quartile (Q1), with a linear trend P value of 0.01. Similarly, higher scores (worse behavioural problems) were observed for internalizing behavioural problems and other emotional and behavioural symptoms related to anxiety, withdrawal, social problems, thought problems and aggressive behaviour. Conclusions: At conception, older maternal age was independently linked to better adolescent cognitive development, whereas advanced paternal age was independently associated with a greater risk of adolescent emotional and behavioral problems. These findings suggest that public health policies targeting an optimal parental age at pregnancy should be developed in the context of offspring developmental consequences. [ABSTRACT FROM AUTHOR]

ABSTRACT The mean age at marriage of Iranian women increased by three years between the mid-1980s and 2000 during a period of great socio-economic change, particularly affecting the 1971-1975 and 1976-1980 birth cohorts. This paper analyses the marriage timing and life course experience of these cohorts of women and highlights the contribution that ethnicity and changes in the socio-economic context made to the sharp marriage delay experienced by the 1976-1980 birth cohort. A discrete time hazard model is applied to the 2000 Iran Demographic and Health Survey data, which are linked to a range of time-varying district-level contextual variables created from the 1986 and 1996 Iranian censuses. The findings suggest that the marriage postponement experienced by the younger birth cohort is related to improvements in women's education and can partly be explained by the increased opportunity costs of marriage, which resulted from limited access to education after marriage. The findings also suggest that differences in marriage timing between areas predominated by certain ethnic groups became less evident for the younger birth cohort. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Background: Increasing age is the biggest risk factor for dementia, of which Alzheimer's disease is the commonest cause. The pathological changes underpinning Alzheimer's disease are thought to develop at least a decade prior to the onset of symptoms. Molecular positron emission tomography and multi-modal magnetic resonance imaging allow key pathological processes underpinning cognitive impairment - including β-amyloid depostion, vascular disease, network breakdown and atrophy - to be assessed repeatedly and non-invasively. This enables potential determinants of dementia to be delineated earlier, and therefore opens a pre-symptomatic window where intervention may prevent the onset of cognitive symptoms.Methods/design: This paper outlines the clinical, cognitive and imaging protocol of "Insight 46", a neuroscience sub-study of the MRC National Survey of Health and Development. This is one of the oldest British birth cohort studies and has followed 5362 individuals since their birth in England, Scotland and Wales during one week in March 1946. These individuals have been tracked in 24 waves of data collection incorporating a wide range of health and functional measures, including repeat measures of cognitive function. Now aged 71 years, a small fraction have overt dementia, but estimates suggest that ~1/3 of individuals in this age group may be in the preclinical stages of Alzheimer's disease. Insight 46 is recruiting 500 study members selected at random from those who attended a clinical visit at 60-64 years and on whom relevant lifecourse data are available. We describe the sub-study design and protocol which involves a prospective two time-point (0, 24 month) data collection covering clinical, neuropsychological, β-amyloid positron emission tomography and magnetic resonance imaging, biomarker and genetic information. Data collection started in 2015 (age 69) and aims to be completed in 2019 (age 73).Discussion: Through the integration of data on the socioeconomic environment and on physical, psychological and cognitive function from 0 to 69 years, coupled with genetics, structural and molecular imaging, and intensive cognitive and neurological phenotyping, Insight 46 aims to identify lifetime factors which influence brain health and cognitive ageing, with particular focus on Alzheimer's disease and cerebrovascular disease. This will provide an evidence base for the rational design of disease-modifying trials. [ABSTRACT FROM AUTHOR]

Abstract Background Evaluating the effectiveness of early years parenting interventions provides evidence to improve the development and wellbeing of children. This protocol paper describes a study to explore the feasibility of evaluating the Incredible Years Toddler early life intervention programme, which is offered to parents of 1–3-year-olds via the Better Start Bradford programme. The study aims to use a Trial within a Cohort Study (TwiCS) design that randomly selects individuals participating in a cohort to be offered an intervention. The TwiCS information and consent process is person-centred and aims to replicate real-world practice whereby only those who are offered the intervention are given information about the intervention. The cohort is the Born in Bradford’s Better Start (BiBBS) cohort, an interventional birth cohort recruiting expectant parents in three areas of Bradford, UK. The study will assess the feasibility of TwiCS procedures, staged consent, and intervention take-up. Methods We will conduct a feasibility TwiCS to test study procedures. We aim to establish the following: (1) whether TwiCS methodology can be implemented to create control and intervention arms, whilst documenting any incidences of contamination within the cohort; (2) whether satisfactory rates of intervention uptake are achieved among participants allocated to the intervention; and (3) whether satisfactory rates of retention of participants in the intervention can be achieved. A Red Amber Green (RAG) rating system has been applied to support the feasibility assessment of each objective: to be rated red (not achieved), amber (partly achieved), and green (achieved). Eligible participants in the BiBBS cohort will be individually randomised 1:1 to the intervention or control arms, with stratification by child age (1 or 2 years old at the time of randomisation) and ethnicity (White British, South Asian, or other). BiBBS researchers will seek consent from participants randomised to the intervention to pass their contact details onto Incredible Years’ delivery agents. Discussion This feasibility study will inform the utility of the TwiCs approach within an experimental birth cohort to evaluate interventions for infants, toddlers, and their families. Trial registration The study was prospectively registered on ISRCTN (ISRCTN16150114).

Congenital malformations are functional and structural alterations in embryonic or foetal development resulting from a variety of factors including maternal health status. This study aimed to investigate the association between maternal birth weight (MBW) and the prevalence of congenital malformations in offspring using data from a nationwide birth cohort study in Japan including 103,060 pregnancies. A binary logistic regression model with adjustment for various covariates revealed that an MBW of <2500 g (low MBW) was associated with an increased risk of congenital heart disease (adjusted odds ratio: 1.388, [95% confidence interval: 1.075–1.792]), angioma (1.491 [1.079–2.059]), and inguinal hernia (1.746, [1.189–2.565]), while those with an MBW of ≥4000 g (high MBW) were associated with congenital anomalies of the urinary tract (2.194, [1.261–3.819]) and arrhythmia (1.775, [1.157–2.725]) compared with those with an MBW of 3000–3499 g. Low MBW was associated with cleft lip and/or palate (1.473, [1.052–2.064]), congenital heart disease (1.615, [1.119–2.332]), genital organs (1.648, [1.130–2.405]), hypospadias (1.804, [1.130–2.881]), and inguinal hernia (1.484, [1.189–1.851]) in male infants and CAKUT (1.619, [1.154–2.273]) in female infants, whereas high MBW was associated with congenital heart disease (1.745, [1.058–2.877]) and CAKUT (2.470, [1.350–4.517]) in male infants. The present study is the first to demonstrate a link between MBW and congenital malformations in Japanese children. While these results must be interpreted with caution, MBW should be considered a major predictor of congenital malformation risk. [ABSTRACT FROM AUTHOR]

This was a record-linkage analysis of a birth cohort to examine the association between self-reported self-harm in adulthood and childhood maltreatment (CM) as prospectively notified to authorities and self-reported on the Child Trauma Questionnaire. There were 2507 participants at 30-year follow-up with data on both CM and self-reported self-harm including an intent to die. Of the participants, 304 (12.1%) had self-harmed at some time in their lives while 150 (4.2%) had wanted to die. The prevalence of self- and agency-reported maltreatment was 513 (20.5%) and 143 (5.7%) respectively. On adjusted analyses, CM irrespective of reporting source showed significant associations with both suicidal outcomes. Physical and emotional abuse showed the strongest associations while findings for neglect were mixed. The only association for sexual abuse was for self-reported maltreatment and intent to die but numbers may have been under-powered. [ABSTRACT FROM AUTHOR]

A fetal growth restriction is related to adverse child outcomes. We investigated risk ratios and population-attributable fractions (PAF) of small-for-gestational-age (SGA) infants in the Japanese population. Among 28,838 infants from five ongoing prospective birth cohort studies under the Japan Birth Cohort Consortium, two-stage individual-participant data meta-analyses were conducted to calculate risk ratios and PAFs for SGA in advanced maternal age, pre-pregnancy underweight, and smoking and alcohol consumption during pregnancy. Risk ratio was calculated using modified Poisson analyses with robust variance and PAF was calculated in each cohort, following common analyses protocols. Then, results from each cohort study were combined by meta-analyses using random-effects models to obtain the overall estimate for the Japanese population. In this meta-analysis, an increased risk (risk ratio, [95% confidence interval of SGA]) was significantly associated with pre-pregnancy underweight (1.72 [1.42–2.09]), gestational weight gain (1.95 [1.61–2.38]), and continued smoking during pregnancy (1.59 [1.01–2.50]). PAF of underweight, inadequate gestational weight gain, and continued smoking during pregnancy was 10.0% [4.6–15.1%], 31.4% [22.1–39.6%], and 3.2% [−4.8–10.5%], respectively. In conclusion, maternal weight status was a major contributor to SGA births in Japan. Improving maternal weight status should be prioritized to prevent fetal growth restriction. [ABSTRACT FROM AUTHOR]

In high‐income nations, multiple micronutrient (MMN) supplementation during pregnancy is a common practice. We aimed to describe maternal characteristics associated with supplement use and daily dose of supplemental nutrients consumed in pregnancy, and whether guideline alignment and nutrient status are related to supplement use. The Queensland Family Cohort is a prospective, Australian observational longitudinal study. Maternal characteristics, nutrient intake from food and supplements, and biochemical nutrient status were assessed in the second trimester (n = 127). Supplement use was reported by 89% of participants, of whom 91% reported taking an MMN supplement. Participants who received private obstetric care, had private health insurance and had greater alignment to meat/vegetarian alternatives recommendations were more likely to report MMN supplement use. Private obstetric care and general practitioner shared care were associated with higher daily dose of supplemental nutrients consumed compared with midwifery group practice. There was high reliance on supplements to meet nutrient reference values for folate, iodine and iron, but only plasma folate concentrations were higher in MMN supplement versus nonsupplement users. Exceeding the upper level of intake for folic acid and iron was more likely among combined MMN and individual supplement/s users, and associated with higher plasma concentrations of the respective nutrients. Given the low alignment with food group recommendations and potential risks associated with high MMN supplement use, whole food diets should be emphasized. This study confirms the need to define effective strategies for optimizing nutrient intake in pregnancy, especially among those most vulnerable where MMN supplement use may be appropriate. Key messages: Multiple micronutrient (MMN) supplementation during pregnancy is a common practice in high‐income countries.Participants who received private obstetric care, had private health insurance and had greater alignment to meat/vegetarian alternatives recommendations were more likely to report MMN supplement use.There was high reliance on supplements to meet intake guidelines for folate, iodine and iron, which also raised concern for excess nutrient intake.This study confirms the need to define effective strategies for optimizing nutrient intake in pregnancy, including the promotion of whole food diets and appropriate use of MMN supplements. [ABSTRACT FROM AUTHOR]

This systematic review (a) identifies birth cohort studies (BCSs) established in the Nordic countries, (b) describes their basic characteristics, and (c) explores how these characteristics have evolved over time, discussing their implications to knowledge production. To identify Nordic BCSs, cohort databases and relevant scientific articles were systematically searched and screened. The review shows that since 1959, more than 600,000 index children have participated in the 79 Nordic BCSs (22 Danish, 20 Finnish, 12 Norwegian, 24 Swedish, one Icelandic), over half of them still ongoing. The Nordic BCSs cover a wide geographical area including the Nordic Arctic. The topics of BCSs have varied over time but most have focused on examining the developmental origins of diseases. A quarter of them had a general scope, while the rest started with a specific focus, commonly atopic diseases. All BCSs collected questionnaire and/or interview data and over 60% of the BCSs announced exclusion criteria for participants, typically insufficient language proficiency. NBCSs have produced crucial scientific knowledge for over six decades, but there are underutilised opportunities including systematic interdisciplinary collaboration, inclusion of children's own views of their health and well-being, intergenerational data collection, and specific knowledge of Arctic indigenous peoples and other minorities. [ABSTRACT FROM AUTHOR]

Background: An individual's overall burden of behavioural and emotional problems across childhood is associated with increased likelihood of later mental health conditions. However, the relative extent of behavioural versus emotional problems ‐ that is, the extent to which the domains are differentiated from one another ‐ may provide additional information about who is at risk of developing a mental health condition. Here, we seek to validate differentiation as an independent predictor of later mental health conditions, and to explore its aetiology. Methods: We analysed data from ~79,000 children in the population‐based Norwegian Mother, Father, and Child Cohort Study, and linked health‐care registries. In preregistered analyses, we modelled the extent and rate of differentiation of behavioural and emotional problems between ages 1.5–5 years, and estimated associations with later symptoms (age 8) and diagnoses (after age 8). We also explored the aetiology of differentiation by estimating associations with early life exposures and, in a subset of 23,945 full siblings, assessing the impact of accounting for unobserved familial confounding. Results: Differentiation of behavioural and emotional problems was associated with later symptoms and diagnoses of mental health conditions, independent of total problems. Maternal at‐risk drinking (β = 0.04 [0.02, 0.06]) and parental relationship problems (β = 0.04 [0.02, 0.05]) were associated with higher behavioural relative to emotional problems at age 5. Maternal prenatal distress (|β| = 0.04 [0.03, 0.06]), concurrent distress (|β| = 0.04 [0.02, 0.06]) and parental education (|β| = 0.05 [0.04, 0.07]) predicted higher emotional relative to behavioural problems at age 5. Estimates for maternal prenatal distress and at‐risk drinking were consistent across both unadjusted and adjusted analyses accounting for unobserved familial risk. Conclusions: Differentiation of behavioural and emotional problems in early childhood represents a valid source of inter‐individual variability linked to the later emergence of psychopathology and may be relevant for early detection and prevention strategies for mental health. [ABSTRACT FROM AUTHOR]

Background: Early interventions are recognised as key to improving life chances for children and reducing inequalities in health and well-being, however there is a paucity of high quality research into the effectiveness of interventions to address childhood health and development outcomes. Planning and implementing standalone RCTs for multiple, individual interventions would be slow, cumbersome and expensive. This paper describes the protocol for an innovative experimental birth cohort: Born in Bradford's Better Start (BiBBS) that will simultaneously evaluate the impact of multiple early life interventions using efficient study designs. Better Start Bradford (BSB) has been allocated £49 million from the Big Lottery Fund to implement 22 interventions to improve outcomes for children aged 0-3 in three key areas: social and emotional development; communication and language development; and nutrition and obesity. The interventions will be implemented in three deprived and ethnically diverse inner city areas of Bradford. Method: The BiBBS study aims to recruit 5000 babies, their mothers and their mothers' partners over 5 years from January 2016-December 2020. Demographic and socioeconomic information, physical and mental health, lifestyle factors and biological samples will be collected during pregnancy. Parents and children will be linked to their routine health and local authority (including education) data throughout the children's lives. Their participation in BSB interventions will also be tracked. BiBBS will test interventions using the Trials within Cohorts (TwiCs) approach and other quasi-experimental designs where TwiCs are neither feasible nor ethical, to evaluate these early life interventions. The effects of single interventions, and the cumulative effects of stacked (multiple) interventions on health and social outcomes during the critical early years will be measured. Discussion: The focus of the BiBBS cohort is on intervention impact rather than observation. As far as we are aware BiBBS is the world's first such experimental birth cohort study. While some risk factors for adverse health and social outcomes are increasingly well described, the solutions to tackling them remain elusive. The novel design of BiBBS can contribute much needed evidence to inform policy makers and practitioners about effective approaches to improve health and well-being for future generations. [ABSTRACT FROM AUTHOR]