Vitamin B12 and folate status in early pregnancy and cardiometabolic risk factors in the offspring at age 5-6 years: findings from the ABCD multi-ethnic birth cohort.

OBJECTIVE: To explore whether maternal vitamin B12 and folate status during early pregnancy are associated with cardiometabolic risk factors in the offspring at age 5-6. DESIGN: Prospective multi-ethnic birth cohort, the Amsterdam Born Children and their Development study (ABCD). SETTING: 12,373 pregnant women living in Amsterdam were approached between 2003 and 2004 for participation in the study. POPULATION: Mother-child pairs for whom information on maternal vitamin B12 or folate status in early gestation and health at age 5-6 years was available (n = 1950). METHODS: Vitamin B12 and folate concentrations were determined in maternal serum at intake in early pregnancy (median 13 weeks' gestation). Anthropometric measurements, blood pressure and fasting blood samples were collected during a health check of children aged 5-6 years. Multiple linear regression was performed to investigate the association between maternal serum concentrations and children's outcomes, corrected for confounders. MAIN OUTCOME MEASURES: Gestational age at birth, birthweight, body mass index (BMI), glucose levels, triglyceride levels, blood pressure and heart rate of the offspring at age 5-6. RESULTS: Low maternal folate levels during early pregnancy were associated with slightly higher BMI in the offspring [decrease per 10 units: ß 0.07 kg/m(2), 95% confidence interval (CI) 0.01, 0.13]. Low maternal vitamin B12 concentrations were associated with higher heart rates (decrease per 100 units: ß 0.49 beats/min, 95% CI 0.11, 0.87). CONCLUSION: This study provides further evidence that maternal nutrition in early pregnancy may possibly program cardiometabolic health of the offspring. TWEETABLE ABSTRACT: Low folate and vitamin B12 levels during pregnancy are associated with higher BMI and heart rate in offspring.

Associations of infant feeding and timing of linear growth and relative weight gain during early life with childhood body composition.

BACKGROUND: Growth and feeding during infancy have been associated with later life body mass index. However, the associations of infant feeding, linear growth and weight gain relative to linear growth with separate components of body composition remain unclear. METHODS: Of 5551 children with collected growth and infant-feeding data in a prospective cohort study (Amsterdam Born Children and their Development), body composition measured using bioelectrical impedance analysis at the age of 5-6 years was available for 2227 children. We assessed how feeding (duration of full breastfeeding and timing of introduction of complementary feeding) and conditional variables representing linear growth and relative weight gain were associated with childhood fat-free mass (FFM) and fat mass (FM). RESULTS: Birth weight was positively associated with both FFM and FM in childhood, and more strongly with FFM than FM. Faster linear growth and faster relative weight gain at all ages in infancy were positively associated with childhood FFM and FM. The associations with FM were stronger for relative weight gain than for linear growth (FM z score: ß coefficient 0.23 (95% con 0.19 to 0.26), P<0.001 and 0.14 (0.11 to 0.17), P<0.001 per s.d. change in relative weight gain and linear growth between 1 and 3 months, respectively). Compared with full breastfeeding <1 month, full breastfeeding >6 months was associated with lower FM (FM z score: -0.17 (-0.28 to -0.05), P=0.005) and lower FFM (FFM z score: -0.13 (-0.23 to -0.03), P=0.015), as was the introduction of complementary feeding >6 months (FM z score: -0.22 (-0.38 to -0.07), P=0.004), compared with <4 months. CONCLUSIONS: Faster infant weight gain is associated with a healthier childhood body composition when it is caused by faster linear growth. Full breastfeeding >6 months and introduction of complementary feeding >6 months are associated with lower childhood FM.

Weight loss in pregnancy and cardiometabolic profile in childhood: findings from a longitudinal birth cohort.

OBJECTIVE: To investigate the consequences of weight loss in pregnancy on pregnancy outcomes and cardiometabolic profile in childhood. DESIGN: Prospective birth cohort (ABCD study). SETTING: Between 2003 and 2004, all pregnant women in Amsterdam were approached for study participation. POPULATION: 7818 pregnant women were included, of which 3165 consented to having their children examined at 5-6 years of age. In 1956 children fasting capillary blood samples were also taken. METHODS: At antenatal booking, women answered questions about their pregnancy and whether they suffered from severe weight loss (SWL; >5 kg). Pregnancy details and outcomes were available through the obstetric caregiver. MAIN OUTCOME MEASURES: At birth main outcome measures were prematurity (<37 weeks) and birthweight. At follow-up, body mass index (BMI), blood pressure, glucose and lipids were assessed. RESULTS: SWL occurred in 6.8% of cases. Women with SWL had similar preterm birth rates compared with women without these complaints (adjusted OR 1.1, 95%CI 0.7, 1.7). Birthweight (adjusted difference - 31 g, 95%CI -76, 15) and BMI at 5-6 years of age (adjusted difference 0.2 kg/m(2) , 95%CI 0.0, 0.5) were similar in children born to mothers with SWL and without SWL, but blood pressure was increased. For diastolic blood pressure this association was independent of confounders (adjusted difference 1.4 mmHg, 95%CI 0.4, 2.4). Lipid and glucose levels were not significantly different between these groups. CONCLUSION: Early pregnancy weight loss, usually occurring as a manifestation of hyperemesis gravidarum, could have long-term consequences for offspring health.

Ethnic differences in maternal underestimation of offspring's weight: the ABCD study.

OBJECTIVE: To determine the ethnic variation in maternal underestimation of their child's weight status and the explanatory role of socio-economic status (SES), acculturation and parental body mass index (BMI). METHOD: A multi-ethnic sample of 2769 normal or overweight/obese children (underweight children excluded) aged 5-7 years was examined (The Amsterdam Born Child and their Development study), comprising five ethnic subgroups: Dutch (n=1744), African descent (n=184), Turkish (n=86), Moroccan (n=161) and other non-Dutch (n=592). Data on mothers' perception of their child's weight status (5-point scale from 'too low' to 'too high'), SES, acculturation, parental BMI and the children's height and weight were collected. Underestimation was defined by comparing maternal perception with the actual weight status of her child (International Obesity Task Force guidelines). Ethnic differences in underestimation were calculated in the normal weight and overweight/obese categories. RESULTS: Underestimation ranged from 3.6 (Dutch) to 15.7% (Moroccan) in normal-weight children, and from 73.0 (Dutch) to 92.3% (Turkish) in overweight/obese children. After correction for ethnic differences in child's BMI, higher odds ratios (ORs) for underestimation were found in the Turkish (normal weight: OR 6.83; 95% confidence interval (CI) 2.33-20.05 and overweight: OR 2.80; 95% CI 1.12-6.98) and Moroccan (normal weight: OR 11.55; 95% CI 5.28-25.26) groups (reference is the Dutch group). Maternal educational level and immigrant generation largely explained the ethnic differences, with a minor contribution of maternal age. After correction, ORs remained higher in the Moroccan group (OR 4.37; 95% CI 1.79-10.62) among the normal-weight children. CONCLUSION: Mothers frequently underestimate the actual weight status of their child, especially mothers from Turkish or Moroccan origin. Having a lower SES, being first-generation immigrant and a young mother are important determinants in explaining these differences. As weight perceptions may affect weight gain and almost all mothers of overweight/obese children underestimate their child's weight, health professionals should help mothers (particularly those from ethnic minority groups) to acquire a realistic perception of their children's weight status.

High levels of antenatal maternal anxiety are associated with altered cognitive control in five-year-old children.

This longitudinal prospective study examined the relation between maternal anxiety during pregnancy and specific aspects of children's cognitive functioning at age five. Antenatal maternal state-anxiety was measured around the 16th week of pregnancy. Children's neurocognitive functioning was examined using a simple reaction time (RT) task, and a choice RT task. Multiple regression analyses in the total sample (N = 922) showed that antenatal anxiety was positively related to children's intra-individual variability in RT in the simple task. In a subsample (n = 100) of women with state-anxiety scores above the 90th percentile, antenatal anxiety was positively associated with mean RT and intra-individual variability in RT in the incompatible trials of the choice RT task. In addition, in this subsample of highly anxious mothers we found a significant positive association in boys but not in girls, between prenatal maternal anxiety and intra-individual variability in RT in the simple task.

Comparison of growth between native and immigrant infants between 0-3 years from the Dutch ABCD cohort.

BACKGROUND: In the Netherlands separate reference charts have been developed for native and immigrant groups to deal with differences in growth patterns in later childhood. The use of these charts, however, is complicated by methodological issues; they do not represent all large Dutch immigrant groups in separate charts despite the differences that have been suggested and the evidence of ethnic disparities in growth dates back to 1997. AIM: Anthropometric measurements from a contemporary multi-ethnic cohort study were created to quantify differences in childhood growth by creating growth charts, separately for boys and girls between the ages of 0-3 years. SUBJECTS AND METHODS: The infants modelled in the charts had a mother born in the Netherlands (n = 3107), Suriname (n = 225), Turkey (n = 203) and Morocco (n = 336). Charts with and without correction for country of origin of the mother were created by using the LMST method. RESULTS: All models including the covariate country of origin of the mother fitted the data better (p < 0.0005), but the observed differences were small. CONCLUSION: Most remarkable differences were found in the BMI and weight measurements for age charts. Especially girls from mothers born in Turkey and Morocco had an increasingly heavier weight for their age than girls from mothers born in the Netherlands.

Anonymous non-response analysis in the ABCD cohort study enabled by probabilistic record linkage.

Selective non-response is an important threat to study validity as it can lead to selection bias. The Amsterdam Born Children and their Development study (ABCD-study) is a large cohort study addressing the relationship between life style, psychological conditions, nutrition and sociodemographic background of pregnant women and their children's health. Possible selective non-response and selection bias in the ABCD-study were analysed using national perinatal registry data. ABCD-study data were linked with national perinatal registry data by probabilistic medical record linkage techniques. Differences in the prevalence of relevant risk factors (sociodemographic and care-related factors) and birth outcomes between respondents and non-respondents were tested using Pearson chi-squared tests. Selection bias (i.e. bias in the association between risk factors and specific outcomes) was analysed by regression analysis with and without adjustment for participation status. The ABCD non-respondents were significantly younger, more often non-western, and more often multiparae. Non-respondents entered antenatal care later, were more often under supervision of an obstetrician and had a spontaneous delivery more often. Non-response however, was not significantly associated with preterm birth (odds ratio 1.10; 95% CI 0.93, 1.29) or low birthweight (odds ratio 1.16; 95% CI 0.98, 1.37) after adjustment for sociodemographic risk factors. The associations found between risk factors and adverse pregnancy outcomes were similar for respondents and non-respondents. Anonymised record linkage of cohort study data with national registry data indicated that selective non-response was present in the ABCD-study, but selection bias was acceptably low and did not influence the main study questions.

Ethnic differences in preterm birth and its subtypes: the effect of a cumulative risk profile.

OBJECTIVE: To explore the effect of potentially explanatory risk factors on ethnic differences in the prevalence of preterm birth (PTB) and its subtypes. DESIGN: Prospective population-based cohort study. SETTING AND POPULATION: Pregnant women from Amsterdam attending their first antenatal visit for obstetric care. A total of 8266 women participated (response rate 67%). Ethnicity was based on the country of birth of the pregnant woman's mother: the Netherlands, Surinam, the Antilles, Turkey, Morocco, Ghana and other non-Dutch countries. Exclusion criteria were multiple births and gestational age at delivery less than 24 weeks. METHODS: Risk factors were obtained using a multilingual questionnaire and from the Dutch Perinatal Registration. Risk factors were summed into a cumulative risk score. Multiple logistic regression analyses were performed. MAIN OUTCOME MEASURES: Odds ratios with 95% CIs were calculated for total, spontaneous and iatrogenic (medically indicated) preterm births for the ethnic minority groups versus the Dutch reference group. RESULTS: After adjustment for all risk factors, the Surinamese (OR 1.6, 95% CI 1.2-2.4), Ghanaian (OR 2.0, 95% CI 1.1-3.6) and Antillean (OR 1.6, 95% CI 0.8-3.3) women had a higher risk of PTB compared with the Dutch women, in particular for iatrogenic preterm birth (OR 2.1, 95% CI 1.0-4.4; OR 3.2, 95% CI 1.0-10.4; OR 3.6, 95% CI 1.1-11.2, respectively). The ethnic minority groups had a higher cumulative risk score (ranging from 2.1 to 3.7) compared with the Dutch group (1.8). Adjustment for the cumulative risk score considerably decreased the risk of PTB among the Surinamese (OR 1.2, 95% CI 0.9-1.7), Ghanaian (OR 1.3, 95% CI 0.8-2.3) and Antillean (OR 1.2, 95% CI 0.6-2.4) women. CONCLUSIONS: A cumulation of risk factors, mainly observed among the ethnic minority groups, contributes to the explanation of ethnic differences in PTB prevalence.

[Breastfeeding in a multi-ethnic population: changes between 2009 and 2015]. / Borstvoeding in een multi-etnische populatie.

OBJECTIVE: To examine changes in breastfeeding rates in 0 to 6 month old infants in Amsterdam, the Netherlands, over the period from 2009 to 2015, for the total population as well as for various ethnic groups. DESIGN: Cross-sectional study. METHOD: Breastfeeding rates were examined for the period from 2009 to 2015 in 165,420 registrations of 75,543 infants at the ages of 2 weeks, 3 months and 6 months for the entire Amsterdam population and for various ethnic groups. Differences were analysed using χ2 tests. RESULTS: The weighted percentage of total breastfeeding (exclusive breastfeeding as well as a combination of breast and formula feeding) increased in the entire Amsterdam study population over the period from 2009 to 2015 (2 weeks: 87.8% to 89.1%; 3 months: 61.6% to 63.6%; 6 months: 39.5% to 42.2%). Increases were mainly the result of increases in weighted percentages for exclusive breastfeeding. The highest exclusive breastfeeding rates were observed among the Turkish ethnic group, the lowest among the Antillean/Aruban and Surinamese groups. CONCLUSION: Percentages for total breastfeeding as well as exclusive breastfeeding in Amsterdam rose over the period from 2009 to 2015, but there is room for improvement. Breastfeeding promotion, whether or not in combination with formula feeding, may be of particular benefit to children of Surinam or Antillean/Aruban descent. Before ethnicity-specific interventions can be implemented, more insight is needed in the reasons for the low breastfeeding rates in specific groups.

No associations of prenatal maternal psychosocial stress with fasting glucose metabolism in offspring at 5-6 years of age.

Highly prevalent maternal psychosocial complaints are accompanied by increases in glucocorticoid stress hormones, which may predispose the offspring for type 2 diabetes and cardiovascular disease later in adulthood. The aim of the current research is to study whether prenatal maternal psychosocial stress is associated with parameters of blood glucose metabolism in their children aged 5-6 years. The study design was a prospective birth cohort (the Amsterdam Born Children and their Development study, the Netherlands). Depressive symptoms, pregnancy-related anxiety, parenting daily hassles and job strain were recorded by questionnaire (gestational week 16). A cumulative score was also calculated. Possible sex differences in the associations were considered. The subjects were 1952 mother-child pairs. Outcome measures were fasting glucose (n=1952), C-peptide and insulin resistance (HOMA2-IR) (n=1478) in the children at the age of 5-6 years. The stress scales, single and cumulative, were not associated with glucose/C-peptide/insulin resistance (all P>0.05). We did not find evidence for sex differences. In conclusion, we did not find evidence for an association between psychosocial stress during early pregnancy and parameters of glucose metabolism in offspring at the age of 5-6 years. Differences emerging later in life or in response to a metabolic challenge should not be ruled out.

Modelling indoor electromagnetic fields (EMF) from mobile phone base stations for epidemiological studies.

Radio frequency electromagnetic fields (RF-EMF) from mobile phone base stations can be reliably modelled for outdoor locations, using 3D radio wave propagation models that consider antenna characteristics and building geometry. For exposure assessment in epidemiological studies, however, it is especially important to determine indoor exposure levels as people spend most of their time indoors. We assessed the accuracy of indoor RF-EMF model predictions, and whether information on building characteristics could increase model accuracy. We performed 15-minute spot measurements in 263 rooms in 101 primary schools and 30 private homes in Amsterdam, the Netherlands. At each measurement location, we collected information on building characteristics that can affect indoor exposure to RF-EMF, namely glazing and wall and window frame materials. Next, we modelled RF-EMF at the measurement locations with the 3D radio wave propagation model NISMap. We compared model predictions with measured values to evaluate model performance, and explored if building characteristics modified the association between modelled and measured RF-EMF using a mixed effect model. We found a Spearman correlation of 0.73 between modelled and measured total downlink RF-EMF from base stations. The average modelled and measured RF-EMF were 0.053 and 0.041mW/m(2), respectively, and the precision (standard deviation of the differences between predicted and measured values) was 0.184mW/m(2). Incorporating information on building characteristics did not improve model predictions. Although there is exposure misclassification, we conclude that it is feasible to reliably rank indoor RF-EMF from mobile phone base stations for epidemiological studies.

Maternal early-pregnancy vitamin D status in relation to linear growth at the age of 5-6 years: results of the ABCD cohort.

BACKGROUND/OBJECTIVES: Low vitamin D status during pregnancy may be associated with infant skeletal growth. However, evidence on the longer-term effect is limited. This study aims to assess the association between maternal vitamin D status in early pregnancy and markers of linear growth (height, leg length and relative leg length) of the child at age 5-6 years. SUBJECTS/METHODS: A subsample of data from the Amsterdam Born Children and Development (ABCD) study was used. Ethnic Dutch pregnant women and their children (n=1208) were included. Maternal serum vitamin D level was determined at first antenatal visit (median 13 weeks, interquartile range: 12-14). We investigated the association of maternal vitamin D, corrected for season, with height, leg length and relative leg length at age 5-6 years. RESULTS: Linear regression analyses showed no significant association between maternal vitamin D levels (nmol/l) and height (cm) (B=-0.006; P=0.205), leg length (cm) (B=-0.002, P=0.540) or relative leg length (%) (B=0.001; P=0.579). Adjustment for potential confounders (parental heights, maternal educational level, alcohol use during pregnancy, child sex, child age at measurement and child screen time) did not change these results. CONCLUSIONS: Maternal vitamin D level was not associated with early linear growth in children. Other factors, such as parental height, appear to be more important.

BMI may underestimate the socioeconomic gradient in true obesity.

BACKGROUND: Body mass index (BMI) does not make a distinction between fat mass and lean mass. In children, high fat mass appears to be associated with low maternal education, as well as low lean mass because maternal education is associated with physical activity. Therefore, BMI might underestimate true obesity in children of low-educated mothers. OBJECTIVE: To investigate the associations of maternal education with fat mass index (FMI), lean mass index (LMI) and BMI. METHODS: In total, 1965 Dutch children from a prospective cohort, aged 5.7 years (standard deviation 0.5), had available data on body composition based on bioelectrical impedance analysis. RESULTS: Maternal education was not associated with BMI after adjustment for confounders. In contrast, children of low-educated mothers had a higher FMI (ß 0.28 95% confidence interval [CI] 0.07; 0.49) and a lower LMI (ß -0.18 95% CI -0.33; -0.03) compared with children of high-educated mothers. CONCLUSIONS: This suggests that BMI underestimates the educational gradient of childhood obesity.

Antenatal maternal anxiety is associated with problem behaviour at age five.

BACKGROUND: Developmental programming by maternal stress during pregnancy is found to influence behavioural development in the offspring. AIM: To prospectively investigate the association between antenatal maternal anxiety and children's behaviour rated by their mothers and teachers. METHODS: In a large, community based birth-cohort (the ABCD-study) antenatal maternal state-anxiety (M = 36.7, SD = 9.8) was measured around the 16th week of gestation. Five years later, 3,446 mothers and 3,520 teachers evaluated 3,758 children's overall problem behaviour, emotional symptoms, conduct problems, hyperactivity/inattention problems, peer relationship problems and pro-social behaviour. RESULTS: Hierarchical multiple regression analysis using a large number of potential covariates revealed that children of mothers who reported higher levels of anxiety during their pregnancy showed more overall problem behaviour, hyperactivity/inattention problems, emotional symptoms, peer relationship problems, conduct problems and showed less pro-social behaviour when mothers rated their child's behaviour. When teachers rated child behaviour, children showed more overall problem behaviour and less pro-social behaviour that was related to antenatal anxiety. The child's sex moderated the association between antenatal anxiety with overall problem behaviour and hyperactivity/inattention problems when reported by the mother. In boys, exposure to antenatal anxiety was associated with a stronger increase in overall problem behaviour compared to girls. Furthermore, antenatal anxiety was significantly related to an increase in hyperactivity/inattention problems in boys, while this was not the case in girls. CONCLUSIONS: Exposure to antenatal maternal anxiety is associated with children's problem behaviour, with different outcome patterns for both sexes. Nevertheless, effect sizes in this study were small.

Ethnic differences in maternal total cholesterol and triglyceride levels during pregnancy: the contribution of demographics, behavioural factors and clinical characteristics.

BACKGROUND/OBJECTIVES: Lipid disturbances during pregnancy may lead to early onset of metabolic diseases in the offspring. However, there is little knowledge on ethnic differences in lipid levels during pregnancy. We evaluated ethnic differences in non-fasting total cholesterol (TC) and triglyceride (TG) levels during early gestation and the role of demographics, behavioural factors and clinical characteristics. SUBJECTS/METHODS: Non-diabetic pregnant women (N=3025) from the Amsterdam Born Children and their Development (ABCD) study. The studied ethnic groups were Dutch, Surinam-Hindustani, African-Caribbean, Turkish, Moroccan and Ghanaian. A multilingual questionnaire was used to gather information on maternal demographics, behavioural factors and clinical characteristics. Non-fasting TC, TG, percentage saturated fatty acid (%SFA) and percentage linoleic acid status (%LA) were assessed in blood samples collected at the first antenatal visit. RESULTS: Ghanaian (-0.51 mmol/l), African-Caribbean (-0.19 mmol/l) and Moroccan (-0.15 mmol/l) women had significant lower TC levels compared with Dutch women. TG levels were lower in Ghanaian (log transformed -0.12 mmol/l) but significantly higher in Surinam-Hindustani (0.10 mmol/l) and Turkish women (0.07 mmol/l). Age, physical activity, pre-pregnancy body mass index (BMI), smoking, %SFA and %LA were independently related to TC and/or TG. However, only pre-pregnancy BMI could partly explain observed disparities. Furthermore, pre-pregnancy BMI had a relatively large effect on TG levels in Surinam-Hindustani and Turkish women. CONCLUSIONS: TC and TG levels differed between ethnic groups during early gestation. Only pre-pregnancy BMI partly explained the ethnic differences to a relevant degree. Reduction in BMI before pregnancy may improve lipid profile, especially in Surinam-Hindustani and Turkish women.

Folic acid knowledge and use in a multi-ethnic pregnancy cohort: the role of language proficiency.

OBJECTIVE: To investigate the role of language proficiency as determinant of folic acid knowledge and use in a multi-ethnic pregnancy cohort. DESIGN: Prospective cohort study. SETTING AND POPULATION: Pregnant women from Amsterdam attending obstetric care for their first antenatal visit. Number approached: 12,373 women, response rate: 67% (8266 women aged 14-49 years). Ethnicity was based on the country of birth: the Netherlands, Surinam, Antilles, Turkey, Morocco, Ghana, other non-Western and other Western countries. MAIN OUTCOME MEASURES: Knowledge about and use of folic acid supplements in pregnancy as elicited in a multilingual questionnaire, as well as determinants of these in ethnic groups separately. RESULTS: Both periconceptional folic acid use and knowledge were significantly lower among Ghanaian, Moroccan, Turkish, and other non-Western women than among women born in the Netherlands or other Western countries. Language proficiency in Dutch was a major determinant of knowledge in all the ethnic groups with a mother tongue other than Dutch [adjusted odds ratios (OR): Western 3.2, non-Western (all countries combined) 7.5], while educational attainment was of secondary importance. Knowledge in turn was the strongest determinant of use (adjusted OR: Western 17.4, non-Western 27.0). CONCLUSIONS: Periconceptional folic acid supplement use among women born in non-Dutch-speaking non-Western countries is low, reflecting a lack of knowledge that is determined by the inability to speak and understand the language of the country of residence. Measures to tackle this problem include the provision of linguistically appropriate information via ethnic health advisors, and language courses integrating health education for immigrants.