Weight trajectories and disordered eating behaviours in 11- to 12-year-olds: A longitudinal study within the Danish National Birth Cohort.

OBJECTIVE: To examine how childhood weight trajectories are associated with disordered eating behaviours (DEBs) in early adolescence. METHODS: Self-reports on DEBs (fasting, purging, and binge eating) were obtained from 18,337 children in the 11-year follow-up of the Danish National Birth Cohort. For this population, birth register information on gestational age and birth weight was categorized into the following: small, appropriate, and large for gestational age. Prospective parent-reported height and weight data at child ages 1 and 7 years were dichotomized using standardized cut-offs into non-overweight and overweight. A 12-category weight trajectory variable was created, and the associations between weight trajectory and DEBs were estimated using logistic regression. RESULTS: In total, 7.0% 11- to 12-year olds reported DEBs. Compared with children born appropriate for gestational age and being non-overweight at age 1 and 7 years, children born small for gestational age and who were overweight at age 1 and 7 years had a very high risk of disordered eating (OR 7.00; CI [2.57, 19.40]). The statistical analyses revealed, however, that overweight at age 7 years was the main contributor and independently of trajectory increased the risk of disordered eating at age 11-12 years significantly (OR 3.16 CI [2.73, 3.65]). CONCLUSION: Overweight not in the first year of life, but at age 7 years was more predictive for DEBs.

Maternal occupation during pregnancy, birth weight, and length of gestation: combined analysis of 13 European birth cohorts.

OBJECTIVES: We assessed whether maternal employment during pregnancy - overall and in selected occupational sectors - is associated with birth weight, small for gestational age (SGA), term low birth weight (LBW), length of gestation, and preterm delivery in a population-based birth cohort design. METHODS: We used data from >200 000 mother-child pairs enrolled in 13 European birth cohorts and compared employed versus non-employed women. Among employees, we defined groups of occupations representing the main sectors of employment for women where potential reproductive hazards are considered to be present. The comparison group comprised all other employed women not included in the occupational sector being assessed. We performed meta-analyses of cohort-specific estimates and explored heterogeneity. RESULTS: Employees had a lower risk of preterm delivery than non-employees [adjusted odds ratio (OR adj) 0.86, 95% confidence interval (95% CI) 0.81-0.91]. Working in most of the occupational sectors studied was not associated with adverse birth outcomes. Being employed as a nurse was associated with lower risk SGA infants (OR adj0.91, 95% CI 0.84-0.99) whereas food industry workers had an increased risk of preterm delivery (OR adj1.50, 95% CI 1.12-2.02). There was little evidence for heterogeneity between cohorts. CONCLUSIONS: This study suggests that, overall, employment during pregnancy is associated with a reduction in the risk of preterm birth and that work in certain occupations may affect pregnancy outcomes. This exploratory study provides an important platform on which to base further prospective studies focused on the potential consequences of maternal occupational exposures during pregnancy on child development.