No / Almost all studies in health research control or investigate socioeconomic position (SEP) as exposure or confounder. Different measures of SEP capture different aspects of the underlying construct, so efficient methodologies to combine them are needed. SEP and ethnicity are strongly associated, however not all measures of SEP may be appropriate for all ethnic groups. Methods We used latent class analysis (LCA) to define subgroups of women with similar SEP profiles using 19 measures of SEP. Data from 11,326 women were used, from eight different ethnic groups but with the majority from White British (40%) or Pakistani (45%) s, who were recruited during pregnancy to the Born in Bradford birth cohort study. Results Five distinct SEP subclasses were identified in the LCA: (i) "Least socioeconomically deprived and most educated" (20%); (ii) "Employed and not materially deprived" (19%); (iii) "Employed and no access to money" (16%); (iv) "Benefits and not materially deprived" (29%) and (v) "Most economically deprived" (16%). Based on the magnitude of the point estimates, the strongest associations were that compared to White British women, Pakistani and Bangladeshi women were more likely to belong to groups: (iv) "benefits and not materially deprived" (relative risk ratio (95% CI): 5.24 (4.44, 6.19) and 3.44 (2.37, 5.00), respectively) or (v) most deprived group (2.36 (1.96, 2.84) and 3.35 (2.21, 5.06) respectively) compared to the least deprived class. White Other women were more than twice as likely to be in the (iv) "benefits and not materially deprived group" compared to White British women and all ethnic groups, other than the Mixed group, were less likely to be in the (iii) "employed and not materially deprived" group than White British women. Conclusions LCA allows different aspects of an individual’s SEP to be considered in one multidimensional indicator, which can then be integrated in epidemiological analyses. Ethnicity is strongly associated with these identified subgroups. Findings from this study suggest a careful use of SEP measures in health research, especially when looking at different ethnic groups. Further replication of these findings is needed in other populations.

BACKGROUND: Various human and animal studies suggest that peak alcohol exposure during a binge episode, rather than total alcohol exposure, may determine fetal development. Research about the impact of binge drinking on birth outcomes is sparse and inconclusive. Data from the Born in Bradford cohort study were used to explore the impact of binge drinking on birth outcomes. METHODS: Interview-administered questionnaire data about the lifestyle and social characteristics of 10 851 pregnancies were linked to maternity and birth data. The impact of self-reported binge drinking (5 units: 40 g of pure alcohol) on two birth outcomes (small for gestational age (SGA) and preterm birth (<37 weeks)) was assessed using multivariate logistic regression models, while adjusting for confounders. RESULTS: The percentage of women classified as binge drinkers fell from 24.5% before pregnancy to 9% during the first trimester and 3.1% during the second trimester. There was a significant association between SGA birth and binge drinking (all categories combined; OR 1.68, 95% CI 1.15 to 2.47, p=0.01). No association was observed between moderate drinking and either birth outcome, or between binge drinking and preterm birth. CONCLUSIONS: Binge drinking during the second trimester of pregnancy was associated with an increased risk of SGA birth. No association was found between any level of alcohol consumption and premature birth. This work supports previous research showing no association between SGA and low-alcohol exposure but adds to evidence of a dose-response relationship with significant risks observed at binge drinking levels.

No / More than 1 billion people live in societies where consanguineous marriages are common. When children are born to consanguineous unions, there is an increased probability of the expression of single-gene disorders with a recessive mode of inheritance. There are presumptive social benefits of consanguineous marriages reported in the literature. METHODS: The UK's Born in Bradford birth cohort study recruited 12 453 women at 26-28 weeks' gestation between 2007 and 2010. In all, 11 396 completed a questionnaire, including questions about their relationship to their baby's father. We compared Pakistani and Other ethnic groups in consanguineous relationships and Pakistani, Other and White British groups not in consanguineous relationships, calculating percentages and age-adjusted prevalence ratios (95% confidence intervals). RESULTS: In the Pakistani group, 59.3% of women (n = 3038) were blood relatives of their baby's father. Consanguinity was uncommon in the Other ethnic group (7.3%, n = 127) and rare (n = 5) in the White British group. Compared with non-consanguineous counterparts, mothers in consanguineous relationships were socially and economically disadvantaged (e.g. never employed, less likely to have higher education). The Pakistani consanguineous group's social, economic and health lifestyle circumstances were equivalent to, in some cases better than, women in non-consanguineous relationships (e.g. up-to-date in paying bills, or in disagreeing that they wished for more warmth in their marital relationship). The consanguineous relationship group had less separation/divorce. Rates of cigarette smoking during pregnancy were lower in mothers in consanguineous relationships. CONCLUSION: Debate about consanguinity should balance the potential protective effect of consanguineous relationships with established genetic risk of congenital anomaly in children.

No / Congenital anomalies are a leading cause of infant death and disability and their incidence varies between ethnic groups in the UK. Rates of infant death are highest in children of Pakistani origin, and congenital anomalies are the most common cause of death in children younger than 12 in this ethnic group. We investigated the incidence of congenital anomalies in a large multiethnic birth cohort to identify the causes of the excess of congenital anomalies in this community. Methods: We obtained questionnaire data from the mothers of children with one or more anomalies from the Born in Bradford study, a prospective birth cohort study of 13 776 babies and their families in which recruitment was undertaken between 2007 and 2011. Details of anomalies were prospectively reported to the study and we cross checked these details against medical records. We linked data for anomalies to maternal questionnaire and clinical data gathered as part of the Born in Bradford study. We calculated univariate and multivariate risk ratios (RRs) with 95% CIs for various maternal risk factors. Findings: Of 11 396 babies for whom questionnaire data were available, 386 (3%) had a congenital anomaly. Rates for congenital anomaly were 305·74 per 10 000 livebirths, compared with a national rate of 165·90 per 10 000. The risk was greater for mothers of Pakistani origin than for those of white British origin (univariate RR 1·96, 95% CI 1·56–2·46). Overall, 2013 (18%) babies were the offspring of first-cousin unions. These babies were mainly of Pakistani origin—1922 (37%) of 5127 babies of Pakistani origin had parents in first-cousin unions. Consanguinity was associated with a doubling of risk for congenital anomaly (multivariate RR 2·19, 95% CI 1·67–2·85); we noted no association with increasing deprivation. 31% of all anomalies in children of Pakistani origin could be attributed to consanguinity. We noted a similar increase in risk for mothers of white British origin older than 34 years (multivariate RR 1·83, 95% CI 1·14–3·00). Maternal education to degree level was protective (0·53, 95% CI 0·38–0·75), irrespective of ethnic origin. Interpretation: Consanguinity is a major risk factor for congenital anomaly. The risk remains even after adjustment for deprivation, and accounts for almost a third of anomalies in babies of Pakistani origin. High levels of educational attainment are associated with reduced risk in all ethnic groups. Our findings will be valuable in health promotion and public health, and to those commissioning antenatal, paediatric, and clinical genetic services. Sensitive advice about the risks should be provided to communities at increased risk, and to couples in consanguineous unions, to assist in reproductive decision making. Funding: National Institute for Health Research Collaboration for Leadership in Applied Health Research and Care programme.

No / The present study aimed to explore previously unreported ethnic differences in infant feeding practices during the introduction of solid foods, accounting for maternal and birth factors, and to determine whether these feeding patterns are associated with BMI at 3 years of age. An observational study using Poisson regression was carried out to investigate the relationship between ethnicity and infant feeding practices and linear regression was used to investigate the relationship between feeding practices and BMI at 3 years of age in a subsample of 1327 infants in Bradford. It was found that compared with White British mothers, mothers of Other ethnicities were less likely to replace breast milk with formula milk before introducing solid foods (adjusted relative risk (RR) – Pakistani: 0·76 (95 % CI 0·64, 0·91), Other South Asian: 0·58 (95 % CI 0·39, 0·86), and Other ethnicities: 0·50 (95 % CI 0·34, 0·73)). Pakistani and Other South Asian mothers were less likely to introduce solid foods early ( < 17 weeks) (adjusted RR – Pakistani: 0·92 (95 % CI 0·87, 0·96) and Other South Asian: 0·87 (95 % CI 0·81, 0·93)). Other South Asian mothers and mothers of Other ethnicities were more likely to continue breast-feeding after introducing solid foods (adjusted RR – 1·72 (95 % CI 1·29, 2·29) and 2·12 (95 % CI 1·60, 2·81), respectively). Pakistani and Other South Asian infants were more likely to be fed sweetened foods (adjusted RR – 1·18 (95 % CI 1·13, 1·23) and 1·19 (95 % CI 1·10, 1·28), respectively) and Pakistani infants were more likely to consume sweetened drinks (adjusted RR 1·72 (95 % CI 1·15, 2·57)). No association between infant feeding practices and BMI at 3 years was observed. Although ethnic differences in infant feeding practices were found, there was no association with BMI at 3 years of age. Interventions targeting infant feeding practices need to consider ethnicity to identify which populations are failing to follow recommendations.

No / The aim of this study was to investigate the relationship between the intake of sugar-sweetened (SS) and artificially sweetened (AS) cola beverages during pregnancy and the risk of preterm delivery (PTD). At baseline (2007–2010), 8914 pregnant women were recruited to the Born in Bradford birth cohort study at 24–28 weeks of pregnancy. Women completed a questionnaire describing their health and lifestyle behaviours, including their consumption of AS and SS cola beverages reported as cups per day, which were then linked to maternity records. The relationship between SS and AS cola beverage consumption was examined using logistic regression analyses. No relationship was observed between daily AS cola beverage consumption and PTD. Women who drank four cups per day of SS cola beverages had higher odds of a PTD when compared with women who did not consume these beverages daily. We conclude that high daily consumption of SS cola beverages during pregnancy is associated with increases in the rate of PTD.