High TSH levels and thyroid autoimmunity in early pregnancy may detrimentally affect pregnancy and birth outcomes.

These findings suggest that women with severe snoring in late pregnancy have a higher risk for fetal-growth-restricted neonates; and women with sleep deprivation have a higher risk for preterm births. The mechanisms underlying these associations remain unclear.

PurposeEssential to exposome research is the collection of data on many environmental exposures from different domains in the same subjects. The aim of the Human Early Life Exposome (HELIX) study was to measure and describe multiple environmental exposures during early life (pregnancy and childhood) in a prospective cohort and associate these exposures with molecular omics signatures and child health outcomes. Here, we describe recruitment, measurements available and baseline data of the HELIX study populations.ParticipantsThe HELIX study represents a collaborative project across six established and ongoing longitudinal population-based birth cohort studies in six European countries (France, Greece, Lithuania, Norway, Spain and the UK). HELIX used a multilevel study design with the entire study population totalling 31 472 mother-child pairs, recruited during pregnancy, in the six existing cohorts (first level); a subcohort of 1301 mother-child pairs where biomarkers, omics signatures and child health outcomes were measured at age 6–11 years (second level) and repeat-sampling panel studies with around 150 children and 150 pregnant women aimed at collecting personal exposure data (third level).Findings to dateCohort data include urban environment, hazardous substances and lifestyle-related exposures for women during pregnancy and their offspring from birth until 6–11 years. Common, standardised protocols were used to collect biological samples, measure exposure biomarkers and omics signatures and assess child health across the six cohorts. Baseline data of the cohort show substantial variation in health outcomes and determinants between the six countries, for example, in family affluence levels, tobacco smoking, physical activity, dietary habits and prevalence of childhood obesity, asthma, allergies and attention deficit hyperactivity disorder.Future plansHELIX study results will inform on the early life exposome and its association with molecular omics signatures and child health outcomes. Cohort data are accessible for future research involving researchers external to the project.

Objectives To investigate the association of trimester-specific gestational weight gain with offspring fetal growth, obesity risk, and cardio-metabolic health outcomes from birth up to 4 years of age. Study design We conducted the present study in 977 mother-child pairs of the pregnancy cohort “Rhea” study in Crete, Greece. We measured birth weight, body mass index from 6 months to 4 years of age, waist circumference, skinfold thickness, blood pressure, and blood levels of lipids, C-reactive protein, and adipose tissue hormones at 4 years of age. We used multiple linear and log Poisson regression models to examine the association of exposure with continuous or binary outcomes respectively. Results Greater rate of gestational weight gain in the first trimester of pregnancy (per 200 g/week) was associated with increased risk of overweight/obesity from 2 years [RR: 1.25, (95% CI: 1.09, 1.42)] to 4 years of age [RR: 1.15, (95% CI: 1.05, 1.25)], but not with birth size. Each 200 gr/week of weight gain in the first trimester of pregnancy was also associated with greater risk of high waist circumference [RR: 1.13, (95% CI: 1.04, 1.23)], high sum of skinfold thickness [RR: 1.15 (95% CI: 1.02, 1.29)] and higher diastolic blood pressure at 4 years of age [β: 0.43 mmHg (95% CI: 0.00, 0.86)]. Greater rate of gestational weight gain during the second and third trimesters of pregnancy (per 200 gr/week) was associated with greater risk of large for gestational age neonates [RR: 1.22, (95% CI: 1.02, 1.45)] and higher levels of cord blood leptin [ratio of geometric means: 1.08 (95% CI: 1.00, 1.17)], but not with child anthropometry at later ages. Conclusion Timing of gestational weight gain may differentially influence childhood cardio-metabolic outcomes.

Maternal diet during pregnancy might influence the development of childhood allergic disorders. The aim of the present study was to evaluate the impact of Mediterranean diet (MD) adherence during pregnancy on wheeze and eczema in the first year of life in two population-based mother -child cohorts in Spain and Greece. We studied 1771 mother -newborn pairs from the Spanish multi-centre 'INMA' (INfancia y Medio Ambiente) study (Gipuzkoa, Sabadell and Valencia) and 745 pairs from the 'RHEA' study in Crete, Greece. The symptoms of wheeze and eczema were based on the criteria of the International Study of Asthma and Allergies in Childhood. Maternal diet during pregnancy was assessed by FFQ and MD adherence was evaluated through an a priori score. Multivariate log-binomial regression models were used to adjust for several confounders in each cohort and summary estimates were obtained by a meta-analysis. MD adherence was not associated with the risk of wheeze and eczema in any cohort, and similar results were identified in the meta-analysis approach. High meat intake (relative risk (RR) 1·22, 95 % CI 1·00, 1·49) and 'processed' meat intake (RR 1·18, 95 % CI 1·02, 1·37) during pregnancy were associated with an increased risk of wheeze in the first year of life, while a high intake of dairy products was significantly associated with a decreased risk of infantile wheeze (RR 0·83, 95 % CI 0·72, 0·96). The results of the present study show that high meat intake during pregnancy may increase the risk of wheeze in the first year of life, while a high intake of dairy products may decrease it.