The Nutri-Score algorithm: Evaluation of its validation process

The Nutri-Score front-of-pack label, which classifies the nutritional quality of products in one of 5 classes (A to E), is one of the main candidates for standardized front-of-pack labeling in the EU. The algorithm underpinning the Nutri-Score label is derived from the Food Standard Agency (FSA) nutrient profile model, originally a binary model developed to regulate the marketing of foods to children in the UK. This review describes the development and validation process of the Nutri-Score algorithm. While the Nutri-Score label is one of the most studied front-of-pack labels in the EU, its validity and applicability in the European context is still undetermined. For several European countries, content validity (i.e., ability to rank foods according to healthfulness) has been evaluated. Studies showed Nutri-Score's ability to classify foods across the board of the total food supply, but did not show the actual healthfulness of products within different classes. Convergent validity (i.e., ability to categorize products in a similar way as other systems such as dietary guidelines) was assessed with the French dietary guidelines; further adaptations of the Nutri-Score algorithm seem needed to ensure alignment with food-based dietary guidelines across the EU. Predictive validity (i.e., ability to predict disease risk when applied to population dietary data) could be re-assessed after adaptations are made to the algorithm. Currently, seven countries have implemented or aim to implement Nutri-Score. These countries appointed an international scientific committee to evaluate Nutri-Score, its underlying algorithm and its applicability in a European context. With this review, we hope to contribute to the scientific and political discussions with respect to nutrition labeling in the EU.

Ethnicity and socioeconomic status are related to dietary patterns at age 5 in the Amsterdam born children and their development (ABCD) cohort

BACKGROUND

Health inequalities are already present at young age and tend to vary with ethnicity and socioeconomic status (SES). Diet is a major determinant of overweight, and studying dietary patterns as a whole in relation to overweight rather than single nutrients or foods has been suggested. We derived dietary patterns at age 5 and determined whether ethnicity and SES were both related to these dietary patterns.

METHODS

We analysed 2769 validated Food Frequency Questionnaires filled in by mothers of children (5.7 ± 0.5y) in the Amsterdam Born Children and their Development (ABCD) cohort. Food items were reduced to 41 food groups. Energy adjusted intake per food group (g/d) was used to derive dietary patterns using Principal Component Analysis and children were given a pattern score for each dietary pattern. We defined 5 ethnic groups (Dutch, Surinamese, Turkish, Moroccan, other ethnicities) and 3 SES groups (low, middle, high, based on maternal education). Multivariate ANOVA, with adjustment for age, gender and maternal age, was used to test potential associations between ethnicity or SES and dietary pattern scores. Post-hoc analyses with Bonferroni adjustment were used to examine differences between groups.

RESULTS

Principal Component Analysis identified 4 dietary patterns: a snacking, full-fat, meat and healthy dietary pattern, explaining 21% of the variation in dietary intake. Ethnicity was related to the dietary pattern scores (p < 0.01): non-Dutch children scored high on snacking and healthy pattern, whereas Turkish children scored high on full-fat and Surinamese children on the meat pattern. SES was related to the snacking, full-fat and meat patterns (p < 0.01): low SES children scored high on the snacking and meat pattern and low on the full-fat pattern.

CONCLUSIONS

This study indicates that both ethnicity and SES are relevant for dietary patterns at age 5 and may enable more specific nutrition education to specific ethnic and low socioeconomic status target groups.

The Influence of Meteorological Factors and Atmospheric Pollutants on the Risk of Preterm Birth

Atmospheric pollutants and meteorological conditions are suspected to be causes of preterm birth. We aimed to characterize their possible association with the risk of preterm birth (defined as birth occurring before 37 completed gestational weeks). We pooled individual data from 13 birth cohorts in 11 European countries (71,493 births from the period 1994-2011, European Study of Cohorts for Air Pollution Effects (ESCAPE)). City-specific meteorological data from routine monitors were averaged over time windows spanning from 1 week to the whole pregnancy. Atmospheric pollution measurements (nitrogen oxides and particulate matter) were combined with data from permanent monitors and land-use data into seasonally adjusted land-use regression models. Preterm birth risks associated with air pollution and meteorological factors were estimated using adjusted discrete-time Cox models. The frequency of preterm birth was 5.0%. Preterm birth risk tended to increase with first-trimester average atmospheric pressure (odds ratio per 5-mbar increase = 1.06, 95% confidence interval: 1.01, 1.11), which could not be distinguished from altitude. There was also some evidence of an increase in preterm birth risk with first-trimester average temperature in the -5°C to 15°C range, with a plateau afterwards (spline coding, P = 0.08). No evidence of adverse association with atmospheric pollutants was observed. Our study lends support for an increase in preterm birth risk with atmospheric pressure.

Excessive infant crying doubles the risk of mood and behavioral problems at age 5: evidence for mediation by maternal characteristics

The onset of behavioral problems starts in early life. This study examined whether excessive infant crying (maternal ratings) is a determinant of emotional and behavioral problems at age 5-6 years. In the Amsterdam Born Children and their Development (ABCD) study, a large prospective, observational, population-based multiethnic birth cohort, excessive infant crying (crying for three or more hours per 24 h day over the past week) during the 13th week after birth (range 11-25 weeks, SD 2 weeks), maternal burden of infant care and maternal aggressive behavior (either angry speaking, or physical aggression) was assessed using a questionnaire. Children's behavioral and emotional problems at the age of 5-6 were assessed by Goodman's Strengths and Difficulties Questionnaire (SDQ), by the subscale of generalized anxiety of the preschool anxiety scale (PAS), and by the Short Mood and Feelings Questionnaire (SMFQ). Inclusion criterion was singleton birth. Exclusion criteria were preterm born babies or congenital disorders. Among 3389 children, excessive infant crying (n = 102) was associated with a twofold increased risk of the overall problem behavior, conduct problems, hyperactivity, and mood problems at the age of 5-6 [ORs between 1.75 (95 % CI 1.09-2.81) and 2.12 (95 % CI 1.30-3.46)]. This association was mediated by maternal burden of infant care (change in odds' ratio 1-17 %) and maternal aggressive behavior (change in odds' ratio 4-10 %). There was no effect modification by the child's gender or maternal parity. Excessive infant crying was not associated with general anxiety problems. Excessive infant crying doubles the risk of behavioral, hyperactivity, and mood problems at the age of 5-6, as reported by their mother. Maternal burden of infant care partially mediates the association between excessive crying and behavioral and mood problems. Special care for mothers with a high burden of care for their excessive crying infant, notwithstanding their own good health, can be a feasible strategy for possible prevention of mood and behavioral problems in their children later in life.

Associations of Infant Feeding and Timing of Weight Gain and Linear Growth during Early Life with Childhood Blood Pressure: Findings from a Prospective Population Based Cohort Study

Objective

Small birth size and rapid postnatal growth have been associated with higher future blood pressure. The timing of these effects, the relative importance of weight gain and linear growth and the role of infant feeding need to be clarified.

Methods

We assessed how blood pressure relates to birth weight, infant and childhood growth and infant feeding (duration of exclusive breastfeeding and timing of introduction of complementary feeding) in 2227 children aged 5 years from a prospective cohort study (Amsterdam Born Children and their Development). Postnatal growth was represented by statistically independent measures of relative weight gain (weight gain independent of height) and linear growth in four age periods during infancy (0–1 month; 1–3 months; 3–6 months; 6–12 months) and from 12 months to 5 years.

Results

Lower birth weight was associated with higher childhood diastolic blood pressure (-0.38 mm Hg.SD^-1; P = 0.007). Faster relative weight gain and linear growth after 1 month were positively associated with systolic and diastolic blood pressure. Associations of linear growth with systolic blood pressure ranged from 0.47 to 1.49 mm Hg.SD^-1; P<0.01 for all. Coefficients were similar for different periods of infancy and also for relative weight gain and linear growth. Compared to breastfeeding <1 month, breastfeeding >1 month was associated with lower blood pressure (e.g. >6 months -1.56 mm Hg systolic blood pressure; P<0.001). Compared to >6 months, introduction of complementary feeding <6 months was associated with higher blood pressure (e.g. 4–6 months 0.91 mm Hg systolic blood pressure; P = 0.004).

Conclusions

After the age of one month faster growth in either weight or height is associated with higher childhood blood pressure. It is unknown whether faster weight gain and linear growth carry the same risk for adult hypertension and cardiovascular morbidity. Longer breastfeeding and delayed introduction of complementary feeding may be associated with lower adult blood pressure.

Outdoor and indoor sources of residential radiofrequency electromagnetic fields, personal cell phone and cordless phone use, and cognitive function in 5-6 years old children

BACKGROUND

Little is known about the exposure of young children to radiofrequency electromagnetic fields (RF-EMF) and potentially associated health effects. We assessed the relationship between residential RF-EMF exposure from mobile phone base stations, residential presence of indoor sources, personal cell phone and cordless phone use, and children's cognitive function at 5-6 years of age.

METHODS

Cross-sectional study on children aged 5-6 years from the Amsterdam Born Children and their Development (ABCD) study, the Netherlands (n=2354). Residential RF-EMF exposure from mobile phone base stations was estimated with a 3D geospatial radio wave propagation model. Residential presence of indoor sources (cordless phone base stations and Wi-Fi) and children's cell phone and cordless phone use was reported by the mother. Speed of information processing, inhibitory control, cognitive flexibility, and visuomotor coordination was assessed using the Amsterdam Neuropsychological Tasks.

RESULTS

Residential presence of RF-EMF indoor sources was associated with an improved speed of information processing. Higher residential RF-EMF exposure from mobile phone base stations and presence of indoor sources was associated with an improved inhibitory control and cognitive flexibility whereas we observed a reduced inhibitory control and cognitive flexibility with higher personal cordless phone use. Higher residential RF-EMF exposure from mobile phone base stations was associated with a reduced visuomotor coordination whereas we observed an improved visuomotor coordination with residential presence of RF-EMF indoor sources and higher personal cell phone use.

CONCLUSIONS

We found inconsistent associations between different sources of RF-EMF exposure and cognitive function in children aged 5-6 years.

Impact of Low Maternal Education on Early Childhood Overweight and Obesity in Europe

BACKGROUND

Comparable evidence on adiposity inequalities in early life is lacking across a range of European countries. This study investigates whether low maternal education is associated with overweight and obesity risk in children from distinct European settings during early childhood.

METHODS

Prospective data of 45 413 children from 11 European cohorts were used. Children's height and weight obtained at ages 4-7 years were used to assess prevalent overweight and obesity according to the International Obesity Task Force definition. The Relative/Slope Indices of Inequality (RII/SII) were estimated within each cohort and by gender to investigate adiposity risk among children born to mothers with low education as compared to counterparts born to mothers with high education. Individual-data meta-analyses were conducted to obtain aggregate estimates and to assess heterogeneity between cohorts.

RESULTS

Low maternal education yielded a substantial risk of early childhood adiposity across 11 European countries. Low maternal education yielded a mean risk ratio of 1.58 (95% confidence interval (CI) 1.34, 1.85) and a mean risk difference of 7.78% (5.34, 10.22) in early childhood overweight, respectively, measured by the RII and SII. Early childhood obesity risk by low maternal education was as substantial for all cohorts combined (RII = 2.61 (2.10, 3.23)) and (SII = 4.01% (3.14, 4.88)). Inequalities in early childhood adiposity were consistent among boys, but varied among girls in a few cohorts.

CONCLUSIONS

Considerable inequalities in overweight and obesity are evident among European children in early life. Tackling early childhood adiposity is necessary to promote children's immediate health and well-being and throughout the life course.

Maternal hypothyroxinaemia in early pregnancy and school performance in 5-year-old offspring

OBJECTIVE

Overt hypothyroidism in pregnant women is associated with a lower intelligence quotient in their children. More recently, subtle decreases in maternal thyroid function have also been associated with neurodevelopmental impairment in offspring. We tested the effect of hypothyroxinaemia during early pregnancy on school performance.

DESIGN

This was a longitudinal study that included the data of 1196 mother-child pairs from the Amsterdam Born Children and Their Development study.

METHODS

Maternal serum free thyroxine (T4) and TSH were obtained at a median gestational age of 12.9 (interquartile range: 11.9-14.3) weeks. School performance was assessed at age 5 years and based on scores obtained in arithmetic and language tests from the national monitoring and evaluation system. Poor school performance was defined as a test result <25th percentile and subnormal school performance as a result <50th percentile of the norm population. To estimate the impact of possible non-response bias, we conducted inverse-probability weighted analyses.

RESULTS

Maternal hypothyroxinaemia (i.e., a maternal free T4 in the lowest 10% of distribution) was associated with a 1.61 (95% CI: 1.05-2.47) -fold increased odds of subnormal arithmetic performance after adjustment for confounders (P=0.03). However, the odds ratio dropped to 1.48 (95% CI: 0.94-2.32) after inverse-probability weighting (P=0.09). No such relations were found with TSH.

CONCLUSIONS

Maternal hypothyroxinaemia at the end of the first trimester was associated with reduced performance in an arithmetic test, but not in a language test, in 5-year-old offspring. However, our results should be interpreted carefully because of possible non-response bias.

Environmental Radiofrequency Electromagnetic Fields Exposure at Home, Mobile and Cordless Phone Use, and Sleep Problems in 7-Year-Old Children

BACKGROUND

We evaluated if exposure to RF-EMF was associated with reported quality of sleep in 2,361 children, aged 7 years.

METHODS

This study was embedded in the Amsterdam Born Children and their Development (ABCD) birth cohort study. When children were about five years old, school and residential exposure to RF-EMF from base stations was assessed with a geospatial model (NISMap) and from indoor sources (cordless phone/WiFi) using parental self-reports. Parents also reported their children's use of mobile or cordless phones. When children were seven years old, we evaluated sleep quality as measured with the Child Sleep Habits Questionnaire (CSHQ) filled in by parents. Of eight CSHQ subscales, we evaluated sleep onset delay, sleep duration, night wakenings, parasomnias and daytime sleepiness with logistic or negative binomial regression models, adjusting for child's age and sex and indicators of socio-economic position of the parents. We evaluated the remaining three subscales (bedtime resistance, sleep anxiety, sleep disordered breathing) as unrelated outcomes (negative control) because these were a priori hypothesised not to be associated with RF-EMF.

RESULTS

Sleep onset delay, night wakenings, parasomnias and daytime sleepiness were not associated with residential exposure to RF-EMF from base stations. Sleep duration scores were associated with RF-EMF levels from base stations. Higher use mobile phones was associated with less favourable sleep duration, night wakenings and parasomnias, and also with bedtime resistance. Cordless phone use was not related to any of the sleeping scores.

CONCLUSION

Given the different results across the evaluated RF-EMF exposure sources and the observed association between mobile phone use and the negative control sleep scale, our study does not support the hypothesis that it is the exposure to RF-EMF that is detrimental to sleep quality in 7-year old children, but potentially other factors that are related to mobile phone usage.

Cardiac Autonomic Nervous System Activation and Metabolic Profile in Young Children: The ABCD Study

Background

In adults, increased sympathetic and decreased parasympathetic nervous system activity are associated with a less favorable metabolic profile. Whether this is already determined at early age is unknown. Therefore, we aimed to assess the association between autonomic nervous system activation and metabolic profile and its components in children at age of 5–6 years.

Methods

Cross-sectional data from an apparently healthy population (within the ABCD study) were collected at age 5–6 years in 1540 children. Heart rate (HR), respiratory sinus arrhythmia (RSA; parasympathetic activity) and pre-ejection period (PEP; sympathetic activity) were assessed during rest. Metabolic components were waist-height ratio (WHtR), systolic blood pressure (SBP), fasting triglycerides, glucose and HDL-cholesterol. Individual components, as well as a cumulative metabolic score, were analyzed.

Results

In analysis adjusted for child’s physical activity, sleep, anxiety score and other potential confounders, increased HR and decreased RSA were associated with higher WHtR (P< 0.01), higher SBP (p<0.001) and a higher cumulative metabolic score (HR: p < 0.001; RSA: p < 0.01). Lower PEP was only associated with higher SBP (p <0.05). Of all children, 5.6% had 3 or more (out of 5) adverse metabolic components; only higher HR was associated with this risk (per 10 bpm increase: OR = 1.56; p < 0.001).

Conclusions

This study shows that decreased parasympathetic activity is associated with central adiposity and higher SBP, indicative of increased metabolic risk, already at age 5–6 years.

Mother's education and the risk of preterm and small for gestational age birth: a DRIVERS meta-analysis of 12 European cohorts

BACKGROUND

A healthy start to life is a major priority in efforts to reduce health inequalities across Europe, with important implications for the health of future generations. There is limited combined evidence on inequalities in health among newborns across a range of European countries.

METHODS

Prospective cohort data of 75 296 newborns from 12 European countries were used. Maternal education, preterm and small for gestational age births were determined at baseline along with covariate data. Regression models were estimated within each cohort and meta-analyses were conducted to compare and measure heterogeneity between cohorts.

RESULTS

Mother's education was linked to an appreciable risk of preterm and small for gestational age (SGA) births across 12 European countries. The excess risk of preterm births associated with low maternal education was 1.48 (1.29 to 1.69) and 1.84 (0.99 to 2.69) in relative and absolute terms (Relative/Slope Index of Inequality, RII/SII) for all cohorts combined. Similar effects were found for SGA births, but absolute inequalities were greater, with an SII score of 3.64 (1.74 to 5.54). Inequalities at birth were strong in the Netherlands, the UK, Sweden and Spain and marginal in other countries studied.

CONCLUSIONS

This study highlights the value of comparative cohort analysis to better understand the relationship between maternal education and markers of fetal growth in different settings across Europe.

Exploring educational disparities in risk of preterm delivery: a comparative study of 12 European birth cohorts

BACKGROUND

An association between education and preterm delivery has been observed in populations across Europe, but differences in methodology limit comparability. We performed a direct cross-cohort comparison of educational disparities in preterm delivery based on individual-level birth cohort data.

METHODS

The study included data from 12 European cohorts from Denmark, England, France, Lithuania, the Netherlands, Norway, Italy, Portugal, and Spain. The cohorts included between 2434 and 99 655 pregnancies. The association between maternal education and preterm delivery (22-36 completed weeks of gestation) was reported as risk ratios, risk differences, and slope indexes of inequality with 95% confidence intervals (CIs).

RESULTS

Singleton preterm live delivery proportion varied between 3.7% and 7.5%. There were large variations between the cohorts in the distribution of education and maternal characteristics. Nevertheless, there were similar educational differences in risk of preterm delivery in 8 of the 12 cohorts with slope index of inequality varying between 2.2 [95% CI 1.1, 3.3] and 4.0 [95% CI 1.4, 6.6] excess preterm deliveries per 100 singleton deliveries among the educationally most disadvantaged, and risk ratio between the lowest and highest education category varying from 1.4 [95% CI 1.1, 1.8] to 1.9 [95% CI 1.2, 3.1]. No associations were found in the last four cohorts.

CONCLUSIONS

Educational disparities in preterm delivery were found all over Europe. Despite differences in the distributions of education and preterm delivery, the results were remarkably similar across the cohorts. For those few cohorts that did not follow the pattern, study and country characteristics did not explain the differences.

[Thinness and overweight in children from Amsterdam: a trend analysis and forecast]

OBJECTIVE

To determine the trends in prevalence of moderate and severe thinness, overweight and obesity in children living in Amsterdam between 2009 and 2013 and estimate prevalences for 2020.

DESIGN

Historical cohort study.

METHOD

158,730 measurements of height and weight of 112,405 children from Amsterdam were analysed. Moderate thinness, severe thinness, overweight and obesity were determined using international BMI cut-off values. Trends were analysed using Generalized Estimating Equations (GEE) for two age groups: pre-schoolers (2 and 3 years) and school-aged children (5, 10 and 14 years). The 'self-projecting method,' which allowed us to extend former trends into the future, was used to estimate prevalences for 2020.

RESULTS

The prevalence of moderate thinness increased significantly in both age groups. The prevalence of severe thinness did not change. The prevalences of overweight and obesity declined significantly in both age groups. These trends were most evident in children of Dutch origin. Other ethnic groups also showed declining prevalences but not in both age groups or both categories of overweight. The prognosis for 2020 shows a further decline in the prevalence of overweight and obesity and an increase in the prevalence of thinness.

CONCLUSION

A decline in the prevalences of overweight and obesity was observed in Amsterdam children, including children of Turkish and Moroccan origin. The prevalence rates are still high, so investing in prevention remains necessary. The prevalence of moderate thinness also seems to be increasing. Continued monitoring of children in all BMI classes is therefore important.

Maternal prepregnancy BMI, offspring's early postnatal growth, and metabolic profile at age 5-6 years: the ABCD Study

CONTEXT

Maternal prepregnancy body mass index (pBMI) and offspring's accelerated postnatal growth have adverse consequences for later cardiometabolic health, but it is unknown how these two factors interact.

OBJECTIVE

To assess the association between maternal pBMI and offspring's metabolic profile at age 5-6 years and determine the role (independent/mediating/moderating) of offspring's postnatal growth in this association.

DESIGN/PARTICIPANTS

In total, 1459 mother-child pairs from the prospective ABCD study with known maternal pBMI, offspring postnatal growth (weight and weight-for-length gain) between age 1-3 months (Δ SD score).

MAIN OUTCOME MEASURES

We analyzed metabolic components of offspring at age 5-6 years, including waist-to-height-ratio (WHtR), systolic/diastolic blood pressure (SBP/DBP), fasting glucose, triglycerides, and high-density lipoprotein-cholesterol values, both individually (Z-scores) and combined (sum Z-scores; metabolic score).

RESULTS

Maternal pBMI was positively associated with offspring's WHtR (β = 0.025; 95% confidence interval [CI], 0.010-0.039), SBP (β = 0.020; 95% CI, 0.005-0.0035), DBP (β = 0.016; 95% CI, 0.000-0.031), and metabolic score (β = 0.078; 95% CI, 0.039-0.118) after adjusting. Adding postnatal growth had no relevant impact on these effect sizes. Postnatal weight gain was independently associated with WHtR (β = 0.199; 95% CI, 0.097-0.300), fasting glucose values (β = 0.117; 95% CI, 0.008-0.227), metabolic score (β = 0.405; 95% CI, 0.128-0.682). Postnatal weight-for-length gain was independently associated with WHtR (β = 0.145; 95% CI, 0.080-0.211), and metabolic score (β = 0.301; 95% CI, 0.125-0.477). An interaction between maternal pBMI and postnatal weight gain was present in the association with SBP (P = .021) and metabolic score (P = .047), and between maternal pBMI and postnatal weight-for-length gain in the association with triglycerides (P = .022) and metabolic score (P = .042).

CONCLUSIONS

Both high maternal pBMI and postnatal accelerated growth are associated with adverse metabolic components in early childhood. No evidence was found for a mediating role of postnatal growth. The combination of high maternal pBMI and postnatal accelerated growth amplified individual effects.

Educational differences in continuing or restarting drinking in early and late pregnancy: role of psychological and physical problems

OBJECTIVE

Many women continue drinking alcohol during pregnancy. This study aimed to describe educational differences in continued drinking in early and late pregnancy and to examine the contribution of psychological and physical factors to the explanation of educational differences.

METHOD

We examined 4,885 women enrolled in the Amsterdam Born Children and their Development study. Information on alcohol intake during pregnancy was based on self-reports at the 16th week of gestation and at 3 months postpartum. Only women who reported alcohol intake before pregnancy were included. Explanatory factors were alcohol intake before pregnancy, psychological problems, and physical problems.

RESULTS

The risk of continued drinking in early pregnancy was increased in higher educated women (odds ratio [OR] = 1.41, 95% CI [1.25, 1.60]); in addition, in late pregnancy, higher educated women had an increased risk of restarting (OR = 1.67, 95% CI [1.37, 2.04]) and continuing drinking (OR = 1.77, 95% CI [1.36, 2.30]). The intensity of alcohol intake before pregnancy and all physical and psychological problems together explained 17.1% and 8.8% of the educational differences in continued drinking in early pregnancy, respectively.

CONCLUSIONS

Higher educated women are more likely to continue drinking during pregnancy. The intensity of alcohol intake before pregnancy and physical and psychological problems contributed to the explanation of continued drinking. However, other factors may play a greater role, such as cultural factors and social norms.

Racial/ethnic and immigrant differences in early childhood diet quality

OBJECTIVE

To assess racial/ethnic differences in the diet in young children and the explanatory role of maternal BMI, immigrant status and perception of child's weight.

DESIGN

Among white, black and Hispanic 3-year-olds, we used negative binomial and linear regression to examine associations of race/ethnicity with foods and nutrients assessed by a validated FFQ.

SETTING

Project Viva, Boston (MA), USA.

SUBJECTS

Children aged 3 years (n 898).

RESULTS

Mean age was 38·3 (sd 2·8) months; 464 (52 %) were boys and 127 mothers (14 %) were immigrants. After adjustment for sociodemographic factors, black and Hispanic children (v. white) had a higher intake of sugar-sweetened beverages (rate ratio (RR) = 2·59 (95 % CI 1·95, 3·48) and RR = 1·59 (95 % CI 1·07, 2·47), respectively) and lower intakes of skimmed/1 % milk (RR = 0·42 (95 % CI 0·33, 0·53) and RR = 0·43 (95 % CI 0·31, 0·61), respectively) and trans-fat (-0·10 (95 % CI -0·18, -0·03) % of energy and -0·15 (95 % CI -0·26, -0·04) % of energy, respectively). Among Hispanics only, a lower intake of snack food (RR = 0·83 (95 % CI 0·72, 0·98)) was found and among blacks only, a higher intake of fast food (RR = 1·28 (95 % CI 1·05, 1·55)) and lower intakes of saturated fat (-0·86 (95 % CI -1·48, -0·23) % of energy), dietary fibre (0·85 (95 % CI 0·08, 1·62) g/d) and Ca (-120 (95 % CI -175, -65) mg/d) were found. Being born outside the USA was associated with more healthful nutrient intakes and less fast food.

CONCLUSIONS

Three-year-old black and Hispanic (v. white) children ate more sugar-sweetened beverages and less low-fat dairy. Total energy intake was substantially higher in Hispanic children. Snack food (Hispanic children) and fat intakes (black children) tended to be lower. Children of immigrants ate less fast food and bad fats and more fibre.

Maternal long-chain polyunsaturated fatty acid status during early pregnancy and children's risk of problem behavior at age 5-6 years

OBJECTIVE

To prospectively investigate the association between maternal long-chain polyunsaturated fatty acid (LCPUFA) status and ratio during pregnancy and children's risk of problem behavior at 5 years of age.

STUDY DESIGN

Maternal LCPUFA status in plasma phospholipids during pregnancy (M = 13.3, SD = 3 weeks) was available for 4336 women. Children's behavior was rated by their mother (n = 2502) and teacher (n = 2061).

RESULTS

When using multivariate logistic regression analyses, we found that greater concentrations of omega-3 fatty acid docosahexaenoic acid (OR 0.75; 95% CI 0.56-0.99; P = .05) decreased children's risk for emotional symptoms. Although lower eicosapentaenoic acid and a greater omega-6:omega-3 LCPUFA (ie, arachidonic acid/[docosahexaenoic acid + eicosapentaenoic acid]) tended to increase the risk for emotional symptoms and the risk of hyperactivity/inattention problems for the omega-6:omega-3 LCPUFA, the results were nonsignificant (P = .07). No evidence was found for mediation by preterm birth and being small for gestational age. The child's sex and infant feeding pattern did not modify the associations.

CONCLUSION

Our results suggest long-term developmental programming influences of maternal LCPUFA status during pregnancy and stress the importance of an adequate and balanced supply of fatty acids in pregnant women for optimal fetal brain development and subsequent long-term behavioral outcomes.

Fish intake during pregnancy, fetal growth, and gestational length in 19 European birth cohort studies

BACKGROUND

Fish is a rich source of essential nutrients for fetal development, but in contrast, it is also a well-known route of exposure to environmental pollutants.

OBJECTIVE

We assessed whether fish intake during pregnancy is associated with fetal growth and the length of gestation in a panel of European birth cohort studies.

DESIGN

The study sample of 151,880 mother-child pairs was derived from 19 population-based European birth cohort studies. Individual data from cohorts were pooled and harmonized. Adjusted cohort-specific effect estimates were combined by using a random- and fixed-effects meta-analysis.

RESULTS

Women who ate fish >1 time/wk during pregnancy had lower risk of preterm birth than did women who rarely ate fish (≤ 1 time/wk); the adjusted RR of fish intake >1 but <3 times/wk was 0.87 (95% CI: 0.82, 0.92), and for intake ≥ 3 times/wk, the adjusted RR was 0.89 (95% CI: 0.84, 0.96). Women with a higher intake of fish during pregnancy gave birth to neonates with a higher birth weight by 8.9 g (95% CI: 3.3, 14.6 g) for >1 but <3 times/wk and 15.2 g (95% CI: 8.9, 21.5 g) for ≥ 3 times/wk independent of gestational age. The association was greater in smokers and in overweight or obese women. Findings were consistent across cohorts.

CONCLUSION

This large, international study indicates that moderate fish intake during pregnancy is associated with lower risk of preterm birth and a small but significant increase in birth weight.

[Ethnic differences in uptake of professional maternity care assistance]

OBJECTIVE

To examine the ethnic differences in the uptake of professional maternity care assistance (MCA) in the Netherlands, and the factors that may explain these differences. Additionally the effect of MCA on health risk behaviour around infants is examined.

DESIGN

Questionnaire survey.

METHOD

Questionnaire data from 3967 mothers from the ABCD study (Amsterdam Born Children and their Development) included during pregnancy in 2003-2004, were used. We examined the explanatory role of ethnicity, age, socioeconomic status, mastery of the Dutch language, parity, housing situation and place of giving birth on MCA uptake, and the effect of MCA uptake on health risk behaviour around infants, such as smoking indoors, infant sleep behaviour, infant nutrition, and response to infant crying.

RESULTS

Mothers of non-Western origin less often used MCA than Dutch mothers (Ghanaian: 70%; Turkish: 75%; Moroccan: 79%; Surinamese: 81%; Dutch Caribbean: 85% vs. Dutch: 95%). Higher educational level, better mastery of the Dutch language, having a paid job and home delivery were all independently associated with the uptake of MCA, and also partially explained ethnic differences in the uptake of MCA. Mothers who received MCA more often breastfed, more often gave vitamin K when not breastfeeding, and more often lived in smoke-free homes. The protective effect of MCA was stronger for non-Western mothers than for Dutch mothers.

CONCLUSION

Mothers of non-Western origin make less use of professional MCA. Given that the use of MCA is associated with a less risk behaviour around infants, efforts should be made to improve the accessibility of professional MCA for mothers of non-Western origin.

Association between infancy BMI peak and body composition and blood pressure at age 5-6 years

INTRODUCTION

The development of overweight is often measured with the body mass index (BMI). During childhood the BMI curve has two characteristic points: the adiposity rebound at 6 years and the BMI peak at 9 months of age. In this study, the associations between the BMI peak and body composition measures and blood pressure at age 5-6 years were investigated.

METHODS

Measurements from the Amsterdam Born Children and their Development (ABCD) study were available for this study. Blood pressure (systolic and diastolic) and body composition measures (BMI, waist-to-height ratio, fat percentage) were gathered during a health check at about 6 years of age (n = 2822). All children had multiple BMI measurements between the 0-4 years of age. For boys and girls separately, child-specific BMI peaks were extracted from mixed effect models. Associations between the estimated BMI peak and the health check measurements were analysed with linear models. In addition, we investigated the potential use of the BMI at 9 months as a surrogate measure for the magnitude of the BMI peak.

RESULTS

After correction for the confounding effect of fetal growth, both timing and magnitude of the BMI peak were significantly and positively associated (p<0.001) with all body composition measures at the age of 5-6 years. The BMI peak showed no direct association with blood pressure at the age 5-6 year, but was mediated by the current BMI. The correlation between the magnitude of the BMI peak and BMI at 9 months was approximately 0.93 and similar associations with the measures at 5-6 years were found.

CONCLUSION

The magnitude of the BMI peak was associated with body composition measures at 5-6 years of age. Moreover, the BMI at 9 months could be used as surrogate measure for the magnitude of the BMI peak.

Maternal Prepregnancy Body Mass Index and Their Children’s Blood Pressure and Resting Cardiac Autonomic Balance at Age 5 to 6 Years

Adverse intrauterine conditions can program hypertension. Because one of the underlying mechanisms is thought to be cardiac autonomic balance, we investigated the association between prepregnancy body mass index (BMI) and blood pressure and indicators of the autonomic balance in the child at age 5 to 6 years. Also investigated was whether these associations were mediated by standardized birth weight and child BMI. Pregnant women (n=3074) participating in the Amsterdam Born Children and their Development study completed a questionnaire at gestational week 14. At age 5 to 6 years, offspring’s sympathetic drive (pre-ejection period), parasympathetic drive (respiratory sinus arrhythmia), and heart rate were measured by electrocardiography and impedance cardiography at rest. Blood pressure was assessed simultaneously. After adjusting for possible maternal/offspring confounders, prepregnancy BMI was positively linearly associated with diastolic blood pressure (β=0.11 mm Hg; 95% confidence interval, 0.05–0.17), systolic blood pressure (β=0.14 mm Hg; 95% confidence interval, 0.07–0.21), but not with heart rate, sympathetic or parasympathetic drive. After adding birth weight and child BMI to the model, the independent effect size of prepregnancy body mass index on systolic blood pressure (β=0.07 mm Hg; 95% confidence interval, 0.00–0.14) and diastolic blood pressure (β=0.07 mm Hg; 95% confidence interval, 0.01–0.13) decreased by ≈50%. Birth weight did not mediate these relationships, but was independently and negatively associated with blood pressure. Child BMI was positively associated with blood pressure and partly mediated the association between prepregnancy BMI and blood pressure. In conclusion, higher prepregnancy BMI is associated with higher blood pressure in the child (aged 5–6 years) but does not seem to be attributable to early alterations in resting cardiac autonomic balance. Child BMI, but not birth weight, mediated the association between prepregnancy BMI and blood pressure.

Smoking overrules many other risk factors for small for gestational age birth in less educated mothers

BACKGROUND

Although there is convincing evidence for the association between small for gestational age (SGA) and socioeconomic status (SES), it is not known to what extent explanatory factors contribute to this association.

AIM

To examine to what extent risk factors could explain educational inequalities in SGA.

STUDY DESIGN

In this study fully completed data were available for 3793 pregnant women of Dutch origin from a population-based cohort (ABCD study). Path-analysis was conducted to examine the role of explanatory factors in the relation of maternal education to SGA.

RESULTS

Low-educated pregnant women had a higher risk of SGA offspring compared to the high-educated women (OR 1.98, 95% CI 1.35-2.89). In path-analysis, maternal cigarette smoking and maternal height explained this association. Maternal age, hypertension, chronic disease, late entry into antenatal care, neighborhood income, underweight, environmental cigarette smoking, drug abuse, alcohol use, caffeine intake, fish intake, folic acid intake, anxiety, and depressive symptoms did not play a role in the association between maternal education and SGA birth.

CONCLUSION

Among a large array of potential factors, the elevated risk of SGA birth among low-educated women appeared largely attributable to maternal smoking and to a lesser extent to maternal height. To reduce educational inequalities more effort is required to include low-educated women especially in prenatal intervention programs such as smoking cessation programs instead of effort into reducing other SGA-risk factors, though these factors might still be relevant at the individual level.

Measuring cardiac autonomic nervous system (ANS) activity in children

The autonomic nervous system (ANS) controls mainly automatic bodily functions that are engaged in homeostasis, like heart rate, digestion, respiratory rate, salivation, perspiration and renal function. The ANS has two main branches: the sympathetic nervous system, preparing the human body for action in times of danger and stress, and the parasympathetic nervous system, which regulates the resting state of the body.

ANS activity can be measured invasively, for instance by radiotracer techniques or microelectrode recording from superficial nerves, or it can be measured non-invasively by using changes in an organ's response as a proxy for changes in ANS activity, for instance of the sweat glands or the heart. Invasive measurements have the highest validity but are very poorly feasible in large scale samples where non-invasive measures are the preferred approach. Autonomic effects on the heart can be reliably quantified by the recording of the electrocardiogram (ECG) in combination with the impedance cardiogram (ICG), which reflects the changes in thorax impedance in response to respiration and the ejection of blood from the ventricle into the aorta. From the respiration and ECG signals, respiratory sinus arrhythmia can be extracted as a measure of cardiac parasympathetic control. From the ECG and the left ventricular ejection signals, the preejection period can be extracted as a measure of cardiac sympathetic control. ECG and ICG recording is mostly done in laboratory settings. However, having the subjects report to a laboratory greatly reduces ecological validity, is not always doable in large scale epidemiological studies, and can be intimidating for young children. An ambulatory device for ECG and ICG simultaneously resolves these three problems.

Here, we present a study design for a minimally invasive and rapid assessment of cardiac autonomic control in children, using a validated ambulatory device ^1-5, the VU University Ambulatory Monitoring System (VU-AMS, Amsterdam, the Netherlands, www.vu-ams.nl).

Maternal hypothyroxinemia in early pregnancy predicts reduced performance in reaction time tests in 5- to 6-year-old offspring

CONTEXT

Overt hypothyroidism in pregnant women is associated with poorer neurodevelopment in their children. Findings from studies investigating the effect of less severe impairments in the maternal thyroid function on cognitive functioning in offspring are difficult to interpret for a number of reasons, including lack of objective cognitive tests, preschool age at assessment, and small sample sizes.

OBJECTIVE

We aimed to assess the effect of the maternal thyroid status in early pregnancy on their offspring's cognitive performance at 5 to 6 years of age.

DESIGN AND PARTICIPANTS

This was a prospective study that included the data of 1765 healthy 5- to 6-year-old children from the Amsterdam Born Children and their Development study. Maternal serum free T4 and TSH were obtained at a median gestational age of 90 (interquartile range, 83 to 100) days.

MAIN OUTCOME MEASURES

Cognitive performance was tested using a computerized assessment program that measured response speed, response speed stability, visuomotor skills, response selection, and response inhibition.

RESULTS

Maternal hypothyroxinemia (ie, maternal free T4 in the lowest 10% of distribution) was associated with a 41.3 (95% confidence interval, 20.3-62.4) ms slower response speed in a simple reaction time task. In this test, it was also associated with a decreased stability in response speed. The relations found persisted after adjustment for family background and perinatal conditions. The effect of hypothyroxinemia on these outcomes was dependent on its interaction with TSH level.

CONCLUSIONS

Lower maternal free T4 concentration at the end of the first trimester predicted slower response speed and decreased stability in response speed in offspring at 5 to 6 years of age.

Preterm birth and small for gestational age in relation to alcohol consumption during pregnancy: stronger associations among vulnerable women? Results from two large Western-European studies

BACKGROUND

Inconsistent data on the association between prenatal alcohol exposure and a range of pregnancy outcomes, such as preterm birth (PTB) and small for gestational age (SGA) raise new questions. This study aimed to assess whether the association between low-moderate prenatal alcohol exposure and PTB and SGA differs according to maternal education, maternal mental distress or maternal smoking.

METHODS

The Amsterdam Born Children and their Development (ABCD) Study (N = 5,238) and the German Health Interview and Examination Survey for Children and Adolescents (KiGGS) (N = 16,301) are both large studies. Women provide information on alcohol intake in early pregnancy, 3 months postpartum and up to 17 years retrospectively. Multivariate logistic regression analyses and stratified regression analyses were performed to examine the association between prenatal alcohol exposure and PTB and SGA, respectively.

RESULTS

No association was found between any level of prenatal alcohol exposure (non-daily, daily, non-abstaining) and SGA. The offspring of daily drinkers and non-abstainers had a lower risk of PTB [ABCD: odds ratio (OR) 0.31, 95% confidence interval (CI) 0.13, 0.77; KiGGS: OR 0.75, 95% CI 0.57, 0.99]. Interactions with maternal education, maternal distress or maternal smoking were not significant.

CONCLUSIONS

Although these results should be interpreted with caution, both studies showed no adverse effects of low-moderate prenatal alcohol exposure on PTB and SGA, not even in the offspring of women who were disadvantaged in terms of low education, high levels of distress, or smoking during pregnancy.

Maternal cell phone and cordless phone use during pregnancy and behaviour problems in 5-year-old children

BACKGROUND

A previous study found an association between maternal cell phone use during pregnancy and maternal-reported child behaviour problems at age 7. Together with cell phones, cordless phones represent the main exposure source of radiofrequency-electromagnetic fields to the head. Therefore, we assessed the association between maternal cell phone and cordless phone use during pregnancy and teacher-reported and maternal-reported child behaviour problems at age 5.

METHODS

The study was embedded in the Amsterdam Born Children and their Development study, a population-based birth cohort study in Amsterdam, the Netherlands (2003-2004). Teachers and mothers reported child behaviour problems using the Strength and Difficulties Questionnaire at age 5. Maternal cell phone and cordless phone use during pregnancy was asked when children were 7 years old.

RESULTS

A total of 2618 children were included. As compared to non-users, those exposed to prenatal cell phone use showed an increased but non-significant association of having teacher-reported overall behaviour problems, although without dose-response relationship with the number of calls (OR=2.12 (95% CI 0.95 to 4.74) for <1 call/day, OR=1.58 (95% CI 0.69 to 3.60) for 1-4 calls/day and OR=2.04 (95% CI 0.86 to 4.80) for ≥5 calls/day). ORs for having teacher-reported overall behaviour problems across categories of cordless phone use were below 1 or close to unity. Associations of maternal cell phone and cordless phone use with maternal-reported overall behaviour problems remained non-significant. Non-significant associations were found for the specific behaviour problem subscales.

CONCLUSION

Our results do not suggest that maternal cell phone or cordless phone use during pregnancy increases the odds of behaviour problems in their children.

The association between interpregnancy interval and birth weight: what is the role of maternal polyunsaturated fatty acid status?

Background

The objective of this study was to evaluate the mediating role of maternal early pregnancy plasma levels of long chain polyunsaturated fatty acids (LCPUFAs) in the association of interpregnancy interval (IPI) with birth weight and smallness for gestational age (SGA) at birth.

Methods

We analysed a subsample of the Amsterdam Born Children and their Development (ABCD) cohort, comprising 1,659 parous pregnant women recruited between January 2003 and March 2004. We used linear and logistic regression to evaluate the associations between fatty acid status, interpregnancy interval and pregnancy outcome.

Results

Low plasma phospholipids concentrations of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and dihomo-gamma-linolenic acid (DGLA), and high concentrations of arachidonic acid (AA) during early pregnancy were associated with reduced birth weight and/or an increased risk of SGA. Short IPIs (< 6 months, with 18–23 months as a reference) were associated with a mean decrease of 207.6 g (SE: ± 73.1) in birth weight (p = 0.005) and a twofold increased risk of SGA (OR: 2.05; CI: 0.93–4.51; p = 0.074). Adjustment for maternal fatty acid concentrations did not affect these results to any meaningful extent.

Conclusions

Despite the observed association of maternal early pregnancy LCPUFA status with birth weight and SGA, our study provides no evidence for the existence of an important role of maternal EPA, DHA, DGLA or AA in the association of short interpregnancy intervals with birth weight and SGA.

Explaining socioeconomic inequalities in childhood blood pressure and prehypertension: the ABCD study

Much remains to be understood about the socioeconomic inequalities in hypertension that continue to exist. We investigated the association of socioeconomic status with blood pressure and prehypertension in childhood. In a prospective cohort, 3024 five- to six-year-old children had blood pressure measurements and available information on potential explanatory factors, namely birth weight, gestational age, smoking during pregnancy, pregnancy-induced hypertension, familial hypertension, maternal body mass index, breastfeeding duration, domestic tobacco exposure, and body mass index. The systolic and diastolic blood pressures of children from mid-educated women were 1.0-mm Hg higher (95% CI, 0.4-1.7) and 0.9-mm Hg higher (95% CI, 0.3-1.4), and the blood pressures of children with low-educated women were 2.2-mm Hg higher (95% CI, 1.4-3.0) and 1.7-mm Hg higher (95% CI, 1.1-2.4) compared with children with high-educated women. Children with mid- (odds ratio, 1.50; 95% CI, 1.18-1.92) or low-educated mothers (odds ratio, 1.80; 95% CI, 1.35-2.42) were more likely to have prehypertension compared with children with high-educated mothers. Using path analyses, birth weight, breastfeeding duration, and body mass index were determined as having a role in the association of maternal education with offspring blood pressure and prehypertension. The socioeconomic gradient in hypertension appears to emerge from childhood as the results show a higher blood pressure and more prehypertension in children from lower socioeconomic status families. Socioeconomic disparities could be reduced by improving 3 factors in particular, namely birth weight, breastfeeding duration, and body mass index, but other factors might also play a role.

Association between body size and blood pressure in children from different ethnic origins

Objective

To assess associations between body size and blood pressure in children (5-6 years) from different ethnic origins.

Method

Five ethnic groups of the ABCD cohort were examined: Dutch (n=1 923), Turkish (n=99), Moroccan (n=187), Black-African (n=67) and Black-Caribbean (n=121). Data on body-mass-index (BMI), waist-to-height ratio (WHtR), fat-mass-index (FMI), and systolic blood pressure (SBP) and diastolic blood pressure (DBP), were collected. Linear regression analysis with restricted cubic splines was used to examine non-linear associations between body size and blood pressure, adjusted for age, sex, height and birth weight.

Results

Ethnic differences were found in associations of BMI with SBP and DBP (SBP: p=0.001 and DBP: p=0.01) and FMI with SBP (p=0.03). BMI and FMI had a relatively large positive association with SBP in Turkish children (BMI: β=2.46mmHg; 95%CI:1.20-3.72; FMI: β=2.41mmHg; 95%CI:1.09-3.73) compared to Dutch (BMI: β=1.31mmHg; 95%CI:0.71-1.92; FMI: β=0.84mmHg; 95%CI:0.23-1.45). Black-Caribbean and Moroccan children showed high blood pressure with low BMI and FMI. Moroccan children showed higher SBP with high BMI and FMI. WHtR was positively associated with SBP and DBP, similar in all ethnic groups. Generally, strongest associations with blood pressure were found for BMI in all ethnic groups.

Conclusion

Ethnic-specific associations between BMI, and FMI and blood pressure are present at young age, with Turkish children showing the highest increase in blood pressure with increasing body size. The higher blood pressure in the Black-Caribbean and Moroccan children with low BMI needs further research. WHtR or FMI do not seem to be associated more strongly to blood pressure than BMI in any ethnic group.

Maternal lipid profile during early pregnancy and pregnancy complications and outcomes: the ABCD study

CONTEXT

Elevated lipid levels during late pregnancy are associated with complications and adverse outcome for both mother and newborn. However, it is inconclusive whether a disturbed lipid profile during early pregnancy has similar negative associations.

OBJECTIVE

Our objective was to investigate whether nonfasting maternal total cholesterol and triglyceride levels during early pregnancy are associated with six major adverse pregnancy outcomes.

METHODS

Data were derived from the Amsterdam Born Children and Their Development (ABCD) cohort study. Random blood samples of nonfasting total cholesterol and triglyceride levels were determined during early gestation (median = 13, interquartile range = 12-14 wk). Outcome measures were pregnancy-induced hypertension (PIH), preeclampsia, preterm birth, small/large for gestational age (SGA/LGA), and child loss. Only nondiabetic women with singleton deliveries were included; the baseline sample consisted of 4008 women. Analysis for PIH and preeclampsia were performed in nulliparous women only (n = 2037).

RESULTS

Mean (sd) triglyceride and total cholesterol levels were 1.33 (0.55) and 4.98 (0.87) mmol/liter, respectively. The incidence of pregnancy complications and perinatal outcomes were as follows: PIH, 4.9%; preeclampsia, 3.7%; preterm birth, 5.3%; SGA, 9.3%; LGA, 9.3%; and child loss, 1.4%. After adjustments, every unit increase in triglycerides was linearly associated with an increased risk of PIH [odds ratio (OR) = 1.60, P = 0.021], preeclampsia (OR = 1.69, P = 0.018), LGA (OR = 1.48, P < 0.001), and induced preterm delivery (OR = 1.69, P = 0.006). No associations were found for SGA or child loss. Total cholesterol was not associated with any of the outcome measures.

CONCLUSIONS

Elevated maternal triglyceride levels measured during early pregnancy are associated with pregnancy complications and adverse pregnancy outcomes. These results suggest that future lifestyle programs in women of reproductive age with a focus on lowering triglyceride levels (i.e. diet, weight reduction, and physical activity) may help to prevent hypertensive complications during pregnancy and adverse birth outcomes.

The association between prenatal psychosocial stress and blood pressure in the child at age 5-7 years

Objective

Prenatal maternal stress could have permanent effects on the offspring’s tissue structure and function, which may predispose to cardiovascular diseases. We investigated whether maternal psychosocial stress is a prenatal factor affecting the blood pressure (BP) of offspring.

Study Design

In the Amsterdam Born Children and their Development (ABCD) study, around gestational week 16, depressive symptoms, state-anxiety, pregnancy-related anxiety, parenting daily hassles and job strain were recorded by questionnaire. A cumulative stress score was also calculated (based on 80^th percentiles). Systolic and diastolic BP and mean arterial pressure (MAP) were measured in the offspring at age 5–7 years. Inclusion criteria were: no use of antihypertensive medication during pregnancy; singleton birth; no reported cardiovascular problems in the child (N = 2968 included).

Results

After adjustment for confounders, the single stress scales were not associated with systolic and diastolic BP, MAP and hypertension (p>0.05). The presence of 3–4 psychosocial stressors prenatally (4%) was associated with 1.5 mmHg higher systolic and diastolic BP (p = 0.046; p = 0.04) and 1.5 mmHg higher MAP in the offspring (p = 0.02) compared to no stressors (46%). The presence of 3–4 stressors did not significantly increase the risk for hypertension (OR 1.8; 95% CI 0.93.4). Associations did not differ between sexes. Bonferroni correction for multiple testing rendered all associations non-significant.

Conclusions

The presence of multiple psychosocial stressors during pregnancy was associated with higher systolic and diastolic BP and MAP in the child at age 5–7. Further investigation of maternal prenatal stress may be valuable for later life cardiovascular health.

Ethnic differences in cardiometabolic risk profile at age 5-6 years: the ABCD study

BACKGROUND

To examine ethnic differences in cardiometabolic risk profile in early age, and explore whether such differences can be explained by differences in body mass index (BMI) or waist circumference (WC).

METHOD

Anthropometric measurements, blood pressure and (in a subsample) fasting blood were collected during a health check of 2,509 children aged 5-6 years. Four ethnic groups were distinguished: Dutch (n=2,008; blood n=1,300), African descent (n=199; blood n=105), Turkish (n=108; blood n=57) and Moroccan (n=194; blood n=94). Ethnic differences in diastolic and systolic blood pressure (DBP/SBP), fasting glucose, low-density lipoprotein (LDL), high-density lipoprotein (HDL) and triglyceride levels were determined and the explanatory role of BMI and WC was examined with regression analysis.

RESULTS

After adjustment for confounders, African descent children showed higher DBP (β2.22 mmHg; 95%CI:1.09-3.36) and HDL levels (β:0.09 mmol/l; 95%CI:0.03-0.16) compared to Dutch children (reference group). Turkish children showed higher SBP (β:1.89 mmHg; 95%CI:0.25-3.54), DBP (β:2.62 mmHg; 95%CI:1.11-4.13), glucose (β:0.12 mmol/L; 95%CI:0.00-0.25) and triglyceride levels (β:0.13 mmol/L; 95%CI:0.02-0.25). Higher BMI values were found in all non-Dutch groups (differences ranged from 0.53-1.03 kg/m(2)) and higher WC in Turkish (β:1.68 cm; 95%CI:0.99-2.38) and Moroccan (β:1.65 cm; 95%CI:1.11-2.19) children. BMI and WC partly explained the higher SBP/DBP and triglyceride levels in Turkish children.

CONCLUSION

Ethnic differences in cardiometabolic profile exist early in life and are partly explained by differences in BMI and WC. African children showed favourable HDL levels and Turkish children the most unfavourable overall profile, whereas their Moroccan peers have less increased cardiometabolic risk in spite of their high BMI and WC.

Socioeconomic inequalities in lipid and glucose metabolism in early childhood in a population-based cohort: the ABCD-Study

Background

Socioeconomic inequalities in cardiovascular disease are pervasive, yet much remains to be understood about how they originate. The objective of this study was to explore the relations of socioeconomic status to lipid and glucose metabolism as indicators of cardiovascular health in 5–6 year olds. Additionally to explore the explanatory role of maternal factors, birth outcome, and child factors.

Methods

In 1308 5–6 year old ethnic Dutch children from the ABCD cohort study, lipids (cholesterol, LDL, HDL, triglycerides), glucose and C-peptide were measured after an overnight-fast.

Results

There were no differences in cholesterol, HDL, LDL, and triglycerides between socioeconomic groups, as indicated by maternal education and income adequacy. However, children of low educated mothers had on average a higher glucose (β = 0.15; 95% confidence interval (CI) 0.03 – 0.27), logC-peptide (β = 0.07; 95% CI 0.04 – 0.09), and calculated insulin resistance (HOMA-IR) (β = 0.15; 95% CI 0.08 – 0.22) compared to children of high educated mothers. Only childhood BMI partly explained these differences (models controlled for age, height, and sex).

Conclusions

The socioeconomic gradient in cardiovascular risk factors seems to emerge in early childhood. In absence of underlying mechanisms these empirical findings are relevant for public health care and further explanatory research.

Psychosocial stress during pregnancy is related to adverse birth outcomes: results from a large multi-ethnic community-based birth cohort

BACKGROUND

Prevalence rates of psychosocial stress during pregnancy are substantial. Evidence for associations between psychosocial stress and birth outcomes is inconsistent. This study aims to identify and characterize different clusters of pregnant women, each with a distinct pattern of psychosocial stress, and investigate whether birth outcomes differ between these clusters.

METHODS

Latent class analysis was performed on data of 7740 pregnant women (Amsterdam Born Children and their Development study). Included constructs were depressive symptoms, state anxiety, job strain, pregnancy-related anxiety and parenting stress.

RESULTS

Five clusters of women with distinct patterns of psychosocial stress were objectively identified. Babies born from women in the cluster characterized as 'high depression and high anxiety, moderate job strain' (12%) had a lower birth weight, and those in the 'high depression and high anxiety, not employed' cluster (15%) had an increased risk of pre-term birth.

CONCLUSIONS

Babies from pregnant women reporting both high levels of anxiety and depressive symptoms are at highest risk for adverse birth outcomes.

Educational inequalities in perinatal outcomes: the mediating effect of smoking and environmental tobacco exposure

OBJECTIVE

Socioeconomic status (SES) is adversely associated with perinatal outcomes. This association is likely to be mediated by tobacco exposure. However, previous studies were limited to single perinatal outcomes and devoted no attention to environmental tobacco exposure. Therefore, this study aimed firstly to explain the role of maternal smoking in the association between maternal education and preterm birth (PTB), low birth weight (LBW) and small for gestational age (SGA), and secondly to explain whether environmental tobacco smoke mediates these associations further.

STUDY DESIGN

This study was nested in a population-based cohort study in the Netherlands, the Amsterdam Born Children and their Development (ABCD) study. Analyses were done in a sample of 3821 pregnant women of Dutch origin, using logistic regression analysis.

RESULTS

Least educated women, who were more often smoking and exposed to environmental tobacco smoke, had a significantly higher risk of PTB (OR 1.95 [95% CI: 1.19-3.20]), LBW (OR 2.41 [95% CI: 1.36-4.27]) and SGA (OR 1.90 [95% CI 1.32-2.74]) than highly educated women. The mediating effect of smoking in the least educated women was 43% for PTB, 55% for LBW and 66% for SGA. Environmental tobacco smoke did not explain these associations further. After adjustment for maternal smoking, the association between lower maternal education and pregnancy outcomes was no longer significant.

CONCLUSIONS

Smoking explains to a considerable extent the association between lower maternal education and adverse perinatal outcomes. Therefore, tobacco-interventions in lower educated women should be primarily focussed on maternal smoking to reduce PTB, LBW, and SGA. Additional attention to environmental tobacco exposure does not seem to reduce educational inequalities in perinatal outcomes.

Ethnic differences in weight retention after pregnancy: the ABCD study

BACKGROUND

Postpartum weight retention contributes to the development of overweight and obesity in women of childbearing age and is more pronounced in ethnic minority groups. This study examined ethnic differences in postpartum weight retention and the explanatory role of socio-economic status (SES), mental health and lifestyle.

METHODS

In the Amsterdam Born Children and their Development (ABCD) study, a large multi-ethnic cohort study conducted in The Netherlands, women filled out questionnaires in the first trimester of pregnancy and 3-5 months postpartum. A total of 4213 women provided data on weight gain, ethnicity, SES, mental health and lifestyle during and after pregnancy. Postpartum weight retention was defined as a difference of ≥5 kg between self-reported pre-pregnancy and postpartum weight. The influence of ethnicity on postpartum weight retention was assessed in logistic regression analyses. Whether the role of ethnicity was attenuated by adding SES, mental health and lifestyle factors were subsequently investigated.

RESULTS

Marked differences in weight change during and after pregnancy were found between ethnic groups. Turkish women had significantly more weight retention than Dutch women. This difference could not be explained by other factors.

CONCLUSION

In the prevention of postpartum weight retention, no single approach seems applicable to all ethnic groups. During pregnancy, health professionals should focus on Turkish women in particular, as they appear to have the highest risk of weight retention.

Prenatal stress and balance of the child's cardiac autonomic nervous system at age 5-6 years

OBJECTIVE

Autonomic nervous system (ANS) misbalance is a potential causal factor in the development of cardiovascular disease. The ANS may be programmed during pregnancy due to various maternal factors. Our aim is to study maternal prenatal psychosocial stress as a potential disruptor of cardiac ANS balance in the child.

METHODS

Mothers from a prospective birth cohort (ABCD study) filled out a questionnaire at gestational week 16 [IQR 12-20], that included validated instruments for state anxiety, depressive symptoms, pregnancy-related anxiety, parenting daily hassles and job strain. A cumulative stress score was also calculated (based on 80(th) percentiles). Indicators of cardiac ANS in the offspring at age 5-6 years are: pre-ejection period (PEP), heart rate (HR), respiratory sinus arrhythmia (RSA) and cardiac autonomic balance (CAB), measured with electrocardiography and impedance cardiography in resting supine and sitting positions.

RESULTS

2,624 mother-child pairs, only single births, were available for analysis. The stress scales were not significantly associated with HR, PEP, RSA and CAB (p≥0.17). Accumulation of maternal stress was also not associated with HR, PEP, RSA and CAB (p≥0.07).

CONCLUSION

Results did not support the hypothesis that prenatal maternal psychosocial stress deregulates cardiac ANS balance in the offspring, at least in rest, and at the age of five-six years.

[Guideline 'Overweight' rather general]

Recently, the guideline for prevention, screening and intervention in respect of overweight in children for the Youth Health Care practice has been published in an abbreviated form in NTvG. Childhood overweight is an important public health problem that requires preventive actions from early age onwards, especially in immigrant groups. Although this guideline provides a basis for (preventive) actions within Youth Health Care, the author argues that a community based approach including specific prevention and intervention strategies for ethnic groups is needed for successful implementation.

Overweight at age two years in a multi-ethnic cohort (ABCD study): the role of prenatal factors, birth outcomes and postnatal factors

BACKGROUND

Childhood overweight/obesity is a major public health problem worldwide which disproportionally affects specific ethnic groups. Little is known about whether such differences already exist at an early age and which factors contribute to these ethnic differences. Therefore, the present study assessed possible ethnic differences in overweight at age 2 years, and the potential explanatory role of prenatal factors, birth outcomes and postnatal factors.

METHODS

Data were derived from a multi-ethnic cohort in the Netherlands (the ABCD study). Weight and height data of 3,156 singleton infants at age 2 years were used. Five ethnic populations were distinguished: Dutch native (n = 1,718), African descent (n = 238), Turkish (n = 162), Moroccan (n = 245) and other non-Dutch (n = 793). Overweight status was defined by the International Obesity Task Force guidelines. The explanatory role of prenatal factors, birth outcomes and postnatal factors in ethnic disparities in overweight (including obesity) was assessed by logistic regression analysis.

RESULTS

Compared to the native Dutch (7.1%), prevalence of overweight was higher in the Turkish (19.8%) and Moroccan (16.7%) group, whereas the prevalence was not increased in the African descent (9.2%) and other non-Dutch (8.8%) group. Although maternal pre-pregnancy body mass index partly explained the ethnic differences, the odds ratio (OR) of being overweight remained higher in the Turkish (OR: 2.66; 95%CI: 1.56-4.53) and Moroccan (OR: 2.11; 95%CI: 1.31-3.38) groups after adjusting for prenatal factors. The remaining differences were largely accounted for by weight gain during the first 6 months of life (postnatal factor). Maternal height, birth weight and gender were independent predictors for overweight at age 2 years, but did not explain the ethnic differences.

CONCLUSION

Turkish and Moroccan children in the Netherlands have 2- to 3-fold higher odds for being overweight at age 2 years, which is largely attributed to maternal pre-pregnancy BMI and weight gain during the first 6 months of life. Further study on the underlying factors of this early weight gain is required to tackle ethnic differences in overweight among these children.

Maternal vitamin B-12 and folate status during pregnancy and excessive infant crying

BACKGROUND

The etiology of excessive infant crying is largely unknown. We hypothesize that excessive infant crying may have an early nutritional origin during fetal development.

AIMS

This study is the first to explore whether (1) maternal vitamin B-12 and folate status during pregnancy are associated with excessive infant crying, and (2) whether and how maternal psychological well-being during pregnancy affects these associations.

STUDY DESIGN

Women were approached around the 12th pregnancy week to complete a questionnaire (n=8266) and to donate a blood sample (n=4389); vitamin B-12 and folate concentrations were determined in serum. Infant crying behavior was measured through a postpartum questionnaire (±3 months; n=5218).

SUBJECTS

Pregnant women living in Amsterdam and their newborn child.

OUTCOME MEASURES

Excessive infant crying, defined as crying ≥3 h/day on average in the past week.

RESULTS

Multiple logistic regression analysis was performed for 2921 (vitamin B-12) and 2622 (folate) women.Vitamin B-12 concentration (categorized into quintiles) was associated with excessive infant crying after adjustment for maternal age, parity, ethnicity, education, maternal smoking and psychological problems (OR[95%CI]: Q1=3.31[1.48-7.41]; Q2=2.50[1.08-5.77]; Q3=2.59[1.12-6.00]; Q4=2.77[1.20-6.40]; Q5=reference). Stratified analysis suggested a stronger association among women with high levels of psychological problems during pregnancy. Folate concentration was not associated with excessive infant crying.

CONCLUSIONS

First evidence is provided for an early nutritional origin in excessive infant crying. A low maternal vitamin B-12 status during pregnancy could, in theory, affect infant crying behavior through two potential mechanisms: the methionine-homocysteine metabolism and/or the maturation of the sleep-wake rhythm.

Cardio-metabolic risk in 5-year-old children prenatally exposed to maternal psychosocial stress: the ABCD study

BACKGROUND

Recent evidence, both animal and human, suggests that modifiable factors during fetal and infant development predispose for cardiovascular disease in adult life and that they may become possible future targets for prevention. One of these factors is maternal psychosocial stress, but so far, few prospective studies have been able to investigate the longer-term effects of stress in detail, i.e. effects in childhood. Therefore, our general aim is to study whether prenatal maternal psychosocial stress is associated with an adverse cardio-metabolic risk profile in the child at age five.

METHODS/DESIGN

Data are available from the Amsterdam Born Children and their Development (ABCD) study, a prospective birth cohort in the Netherlands. Between 2003-2004, 8,266 pregnant women filled out a questionnaire including instruments to determine anxiety (STAI), pregnancy related anxiety (PRAQ), depressive symptoms (CES-D), parenting stress (PDH scale) and work stress (Job Content Questionnaire). Outcome measures in the offspring (age 5-7) are currently collected. These include lipid profile, blood glucose, insulin sensitivity, body composition (body mass index, waist circumference and bioelectrical impedance analysis), autonomic nervous system activity (parasympathetic and sympathetic measures) and blood pressure. Potential mediators are maternal serum cortisol, gestational age and birth weight for gestational age (intrauterine growth restriction). Possible gender differences in programming are also studied.

DISCUSSION

Main strengths of the proposed study are the longitudinal measurements during three important periods (pregnancy, infancy and childhood), the extensive measurement of maternal psychosocial stress with validated questionnaires and the thorough measurement of the children's cardio-metabolic profile. The availability of several confounding factors will give us the opportunity to quantify the independent contribution of maternal stress during pregnancy to the cardio-metabolic risk profile of her offspring. Moreover, the mediating role of maternal cortisol, intrauterine growth, gestational age and potential gender differences can be explored extensively. If prenatal psychosocial stress is indeed found to be associated with the offspring's cardio-metabolic risk, these results support the statement that primary prevention of cardiovascular disease may start even before birth by reducing maternal stress during pregnancy.

First-trimester working conditions and birthweight: a prospective cohort study

OBJECTIVES

We investigated the relationship between women's first-trimester working conditions and infant birthweight.

METHODS

Pregnant women (N = 8266) participating in the Amsterdam Born Children and Their Development study completed a questionnaire gathering information on employment and working conditions. After exclusions, 7135 women remained in our analyses. Low birthweight and delivery of a small-for-gestational-age (SGA) infant were the main outcome measures.

RESULTS

After adjustment, a workweek of 32 hours or more (mean birthweight decrease of 43 g) and high job strain (mean birthweight decrease of 72 g) were significantly associated with birthweight. Only high job strain increased the risk of delivering an SGA infant (odds ratio [OR] = 1.5; 95% confidence interval [CI] = 1.1, 2.2). After adjustment, the combination of high job strain and a long workweek resulted in the largest birthweight reduction (150 g) and the highest risk of delivering an SGA infant (OR = 2.0; 95% CI = 1.2, 3.2).

CONCLUSIONS

High levels of job strain during early pregnancy are associated with reduced birthweight and an increased risk of delivering an SGA infant, particularly if mothers work 32 or more hours per week.

Early growth patterns and cardiometabolic function at the age of 5 in a multiethnic birth cohort: the ABCD study

BACKGROUND

The relation between fetal growth retardation and cardiovascular and metabolic diseases in later life has been demonstrated in many studies. However, debate exists around the potential independent role of postnatal growth acceleration. Furthermore, it is unknown whether a potential effect of growth acceleration on cardiovascular and metabolic function is confined to certain time frames.The present study assesses the (predictive) role of prenatal and postnatal growth on 5 components of cardiovascular and metabolic function in children aged 5. The potential association of timing of postnatal growth acceleration with these outcomes will be explored.

METHODS AND DESIGN

Prospective multiethnic community-based cohort study of 8266 pregnancies (Amsterdam Born Children and their Development, ABCD study). Up till now, anthropometry of 5104 children from the original cohort was followed during the first 5 years of life, with additional information about birth weight, pregnancy duration, and various potential confounding variables.At age 5, various components of cardiovascular and metabolic function are being measured. Outcome variables are body size, body composition and fat distribution, insulin sensitivity, lipid profile, blood pressure and autonomic regulation of cardiovascular function.

DISCUSSION

This study will be one of the first population-based prospective cohort studies to address the association between measures of both prenatal and postnatal growth and various components of cardiovascular and metabolic function. Specific attention is paid to the timing of acceleration in growth and its potential association with the outcome variables. Importantly, the longitudinal design of this study gives us the opportunity to gain more insight into growth trajectories associated with adverse outcomes in later life. If identified as an independent risk factor, this provides further basis for the hypothesis that accelerated growth during the first years of life is a modifiable factor for the prevention of cardiovascular and metabolic disorders in later life. Moreover, identification of specific vulnerable periods during development may reveal suitable time frames for early interventions.