Maternal folic acid use during pregnancy, methylenetetrahydrofolate reductase gene polymorphism, and child's lung function and asthma.

BACKGROUND: Folic acid supplement use during pregnancy might affect childhood respiratory health, potentially mediated by methylenetetrahydrofolate reductase polymorphism C677T (MTHFR-C677T) carriership. OBJECTIVES: We examined the associations of maternal folic acid supplement use and folate, vitamin B12 and homocysteine concentrations during pregnancy with childhood lung function and asthma. METHODS: This study was embedded in a population-based prospective cohort study among 5653 children. Folic acid supplement use was assessed by questionnaires. Folate, vitamin B12 and homocysteine plasma concentrations were measured in early pregnancy and at birth. At age 10 years, forced expiratory volume in 1 second (FEV1 ), forced vital capacity (FVC), FEV1 /FVC, forced expiratory flow between 25% and 75% (FEF25-75 ), at 75% of FVC (FEF75 ), and asthma were examined. RESULTS: Maternal folic acid supplement use during pregnancy was associated with higher childhood FEV1 and FVC and with a lower FEV1 /FVC, compared with no folic acid supplement use. Among mothers carrying MTHFR-C677T variants, preconceptional start of folic acid supplement use was associated with lower FEV1 /FVC (-0.17 [-0.32, -0.02]) and FEF25-75 (-0.24 [-0.40, -0.07]). Among children carrying MTHFR-C677T wild-type, a higher vitamin B12 level at birth was associated with a lower FEV1 (-0.07 [-0.12, -0.01]) and FVC (-0.09 [-0.15, -0.04]). Folate and homocysteine concentrations were not consistently associated with lower childhood lung function or asthma. CONCLUSIONS: Preconceptional start of maternal folic acid supplement use and higher vitamin B12 concentrations at birth might adversely affect childhood lung function depending on MTHFR-C677T carriership. The clinical implications need to be evaluated.

Gestational vitamin D deficiency and autism-related traits: the Generation R Study.

There is intense interest in identifying modifiable risk factors associated with autism-spectrum disorders (ASD). Autism-related traits, which can be assessed in a continuous fashion, share risk factors with ASD, and thus can serve as informative phenotypes in population-based cohort studies. Based on the growing body of research linking gestational vitamin D deficiency with altered brain development, this common exposure is a candidate modifiable risk factor for ASD and autism-related traits. The association between gestational vitamin D deficiency and a continuous measure of autism-related traits at ~6 years (Social Responsiveness Scale; SRS) was determined in a large population-based cohort of mothers and their children (n=4229). 25-hydroxyvitamin D (25OHD) was assessed from maternal mid-gestation sera and from neonatal sera (collected from cord blood). Vitamin D deficiency was defined as 25OHD concentrations less than 25 nmol l-1. Compared with the 25OHD sufficient group (25OHD>50 nmol l-1), those who were 25OHD deficient had significantly higher (more abnormal) SRS scores (mid-gestation n=2866, ß=0.06, P<0.001; cord blood n=1712, ß=0.03, P=0.01). The findings persisted (a) when we restricted the models to offspring with European ancestry, (b) when we adjusted for sample structure using genetic data, (c) when 25OHD was entered as a continuous measure in the models and (d) when we corrected for the effect of season of blood sampling. Gestational vitamin D deficiency was associated with autism-related traits in a large population-based sample. Because gestational vitamin D deficiency is readily preventable with safe, cheap and accessible supplements, this candidate risk factor warrants closer scrutiny.

Maternal plasma polyunsaturated fatty acid levels during pregnancy and childhood lipid and insulin levels.

BACKGROUND AND AIMS: Maternal polyunsaturated fatty acid (PUFA) levels are associated with cord blood lipid and insulin levels. Not much is known about the influence of maternal PUFAs during pregnancy on long-term offspring lipid and insulin metabolism. We examined the associations of maternal plasma n-3 and n-6 PUFA levels during pregnancy with childhood lipid and insulin levels. METHODS AND RESULTS: In a population-based prospective cohort study, among 3230 mothers and their children, we measured maternal second trimester n-3 and n-6 PUFA plasma levels. At the median age of 6.0 years (95% range, 5.6-7.9), we measured childhood total-cholesterol, high-density lipoprotein (HDL)-cholesterol, low-density lipoprotein (LDL)-cholesterol, triglyceride, insulin and c-peptide levels. Higher maternal total n-3 PUFA levels, and specifically DHA levels, were associated with higher childhood total-cholesterol, HDL-cholesterol and insulin levels (p-values <0.05), but not with LDL-cholesterol and triglycerides. Maternal total n-6 PUFA levels were not associated with childhood outcomes, but higher levels of the individual n-6 PUFAs, EDA and DGLA were associated with a lower childhood HDL-cholesterol, and higher AA levels with higher childhood total-cholesterol and HDL-cholesterol levels (all p-values <0.05). A higher maternal n-6/n-3 PUFA ratio was only associated with lower childhood HDL-cholesterol and insulin levels (p-values <0.05). These associations were not explained by childhood body mass index. CONCLUSIONS: Higher maternal total n-3 PUFAs and specifically DHA levels during pregnancy are associated with higher childhood total-cholesterol, HDL-cholesterol and insulin levels. Only individual maternal n-6 PUFAs, not total maternal n-6 PUFA levels, tended to be associated with childhood lipid and insulin levels.

Infant dietary patterns and bone mass in childhood: the Generation R Study.

UNLABELLED: Early life nutrition affects peak bone mass attainment. In this prospective cohort study, children with high adherence to a "dairy and whole grains" pattern in infancy had higher bone mineral density at the age of 6 years. Although the observed effects are small, our study provides insight into mechanisms linking early nutrition to bone acquisition in childhood. INTRODUCTION: Nutrition in early life may affect peak bone mass attainment. Previous studies on childhood nutrition and skeletal health mainly focused on individual nutrients, which does not consider the cumulative effects of nutrients. We investigated the associations between dietary patterns in infancy and childhood bone health. METHODS: This study included 2850 children participating in a population-based prospective cohort study. Dietary information was obtained from a food frequency questionnaire at the age of 13 months. Using principal component analysis, three major dietary patterns were extracted, explaining in total 30% of the variation in dietary intake. At the age of 6 years, a total body dual-energy X-ray absorptiometry (DXA) scan was performed, and bone mineral density (BMD), bone mineral content (BMC), area-adjusted BMC (aBMC), and bone area (BA) were analyzed. RESULTS: Higher adherence score to a "dairy and whole grains" pattern was positively associated with BMD and aBMC, but not with BMC and BA. Accordingly, children in the highest quartile of the "dairy and whole grains" pattern had higher BMD (difference 3.98 mg/cm(2), 95% confidence interval (CI) 0.36 to 7.61) and aBMC (difference 4.96 g, 95% CI 1.27 to 8.64) than children in the lowest quartile. Stratification for vitamin D supplementation showed that the positive associations between the "dairy and whole grains" pattern and bone outcomes were only observed in children who did not receive vitamin D supplementation. A "potatoes, rice, and vegetables" and a "refined grains and confectionery" pattern were not consistently associated with bone outcomes. CONCLUSIONS: An infant dietary pattern characterized by high intakes of dairy and cheese, whole grains, and eggs is positively associated with bone development in childhood. Further research is needed to investigate the consequences for bone health in later life.

Maternal fish consumption during pregnancy and risks of wheezing and eczema in childhood: the Generation R Study.

BACKGROUND/OBJECTIVES: Maternal fish consumption during pregnancy might influence the fetal immune system through anti-inflammatory effects of omega-3 fatty acids, and might affect the risks of childhood asthma and atopy. In Generation R, a prospective cohort study in the Netherlands, we examined the associations of first trimester fish consumption with childhood wheezing and eczema in the first 4 years of life. METHODS: In total, 2976 mothers completed a 293-item semiquantitative food frequency questionnaire covering dietary intake in the first trimester. The occurrence of wheezing and eczema was yearly assessed by questionnaires. RESULTS: Median weekly fish consumption was 83 (95% range 0-316) grams per week. We observed no consistent associations of maternal total-, lean- or fatty-fish consumption during pregnancy with the risks of childhood wheezing. Maternal shellfish consumption of 1-13 g per week was associated with overall increased risks of childhood wheezing and eczema (OR 1.20 (1.04, 1.40) and OR 1.18 (1.01, 1.37), respectively). Maternal fatty fish consumption of 35-69 g per week was associated with increased overall risks of childhood eczema (OR 1.17 (1.00, 1.38)), but maternal total- or lean-fish consumption was not. CONCLUSIONS: During pregnancy, shellfish consumption was associated with increased risks of wheezing and eczema, while fatty fish consumption was associated with a higher risk of eczema only. Maternal total fish or lean fish consumption were not associated with wheezing or eczema. Further studies are needed to replicate these findings and to explore underlying mechanisms.

OS036. Ethnic differences in blood pressure and hypertensivecomplications during pregnancy; the generation R Study.

INTRODUCTION: Blood pressure levels during pregnancy are important risk factors for gestational hypertensive disorders. Non-pregnant women from ethnic minority groups are found to have higher blood pressure levels compared to white women. Little is known about variation in blood pressure development during pregnancy across different ethnic groups. OBJECTIVES: To investigate ethnic differences in blood pressure levels in each trimester of pregnancy and the risk of gestational hypertensive disorders and the degree to which such differences can be explained by education and lifestyle related factors. METHODS: The study included 6215 women participating in a population-based prospective cohort study from early pregnancy onwards in Rotterdam, The Netherlands. Ethnicity was assessed at enrolment. Blood pressure was measured in each trimester. Information about gestational hypertensive disorders was available from medical records. Lifestyle factors included smoking, alcohol, caffeine intake, folic acid supplementation, sodium and energy intake, body mass index and maternal stress. Associations and explanatory pathways were investigated using linear and logistic regression analysis. RESULTS: Dutch pregnant women had higher systolic blood pressure levels as compared to women in other ethnic groups in each trimester of pregnancy. Compared to Dutch women, Turkish and Moroccan women had lower diastolic blood pressure levels in each trimester. These differences remained after adjusting for education and lifestyle factors. Turkish and Moroccan women had a lower risk of gestational hypertension as compared to Dutch women (OR 0.32; 95% CI: 0.18, 0.58 and OR 0.28; 95% CI: 0.14, 0.58) and Cape Verdean women had an elevated risk of preeclampsia (OR 2.22; 95% CI: 1.22, 4.07). Differences could not be explained by education or lifestyle. CONCLUSION: Substantial ethnic differences were observed in blood pressure levels in each trimester of pregnancy and risk of gestational hypertensive disorders. A wide range of potential explanatory variables could not explain these differences.

Explaining differences in birth outcomes in relation to maternal age: the Generation R Study.

OBJECTIVE: To examine the association between maternal age and birth outcomes, and to investigate the role of sociodemographic and lifestyle-related determinants. DESIGN: Population-based prospective cohort study from early pregnancy onwards. SETTING: Rotterdam, the Netherlands. POPULATION: A cohort of 8568 mothers and their children. METHODS: Maternal age was assessed at enrolment. Information about sociodemographic (height, weight, educational level, ethnicity, parity) and lifestyle-related determinants (alcohol consumption, smoking habits, folic acid supplement use, caffeine intake, daily energy intake) and birth outcomes was obtained from questionnaires and hospital records. Multivariate linear and logistic regression analyses were used. MAIN OUTCOMES MEASURES: Birthweight, preterm delivery, small-for-gestational-age, and large-for-gestational-age. RESULTS: As compared with mothers aged 30-34.9 years, no differences in risk of preterm delivery were found. Mothers younger than 20 years had the highest risk of delivering small-for-gestational-age babies(OR 1.6, 95% CI: 1.1-2.5); however, this increased risk disappeared after adjustment for sociodemographic and lifestyle-related determinants. Mothers older than 40 years had the highest risk of delivering large-for-gestational-age babies (OR 1.3, 95% CI: 0.8-2.4). The associations of maternal age with the risks of delivering large-for-gestational-age babies could not be explained by sociodemographic and lifestyle-related determinants. CONCLUSIONS: As compared with mothers aged 30-34.9 years, younger mothers have an increased risk of small-for-gestational-age babies, whereas older mothers have an increased risk of large-for-gestational-age babies. Sociodemographic and lifestyle-related determinants cannot fully explain these differences.

Folic acid is positively associated with uteroplacental vascular resistance: the Generation R study.

BACKGROUND AND AIMS: Periconception folic acid supplementation may influence early placentation processes and thereby the occurrence of hypertensive pregnancy disorders. For this reason we examined the associations between periconception folic acid supplementation and uteroplacental vascular resistance, blood pressure, and the risks of gestational hypertension and preeclampsia, in 5993 pregnant women, participating in a population-based cohort study. METHODS AND RESULTS: Folic acid supplementation was assessed by questionnaire. Mean pulsatility index (PI) and resistance index (RI) of the uterine (UtA) and umbilical arteries (UmA) were measured by Doppler ultrasound in mid- and late pregnancy. Systolic and diastolic blood pressures (SBP, DBP) were measured in early, mid- and late pregnancy. Compared to women who did not use folic acid, preconception folic acid users had a slightly lower UtA-RI in mid-pregnancy [ß -0.02, 95% confidence interval (CI) -0.03, -0.01] and late pregnancy [ß -0.02, 95% CI -0.03, -0.001], a lower UtA-PI in mid-pregnancy [ß -0.06, 95% CI -0.1, -0.03] and late pregnancy [ß -0.03, 95% CI -0.05, -0.01], as well as tendencies towards a lower UmA-PI in mid-pregnancy [ß -0.02, 95% CI -0.04, -0.001] and late pregnancy [ß -0.01, 95% CI -0.02, 0.01]. Additionally, these women had slightly higher SBP and DBP throughout pregnancy. Neither the patterns of blood-pressure change during pregnancy, nor the risk of gestational hypertension and preeclampsia differed between the folic acid categories. CONCLUSION: Periconception folic acid supplementation is associated with lower uteroplacental vascular resistance and higher blood pressures during pregnancy. The effects are small and within physiologic ranges and seem not associated with the risk of hypertensive pregnancy disorders.

Explaining ethnic differences in late antenatal care entry by predisposing, enabling and need factors in The Netherlands. The Generation R Study.

Despite compulsory health insurance in Europe, ethnic differences in access to health care exist. The objective of this study is to investigate how ethnic differences between Dutch and non-Dutch women with respect to late entry into antenatal care provided by community midwifes can be explained by need, predisposing and enabling factors. Data were obtained from the Generation R Study. The Generation R Study is a multi-ethnic population-based prospective cohort study conducted in the city of Rotterdam. In total, 2,093 pregnant women with a Dutch, Moroccan, Turkish, Cape Verdean, Antillean, Surinamese Creole and Surinamese Hindustani background were included in this study. We examined whether ethnic differences in late antenatal care entry could be explained by need, predisposing and enabling factors. Subsequently, logistic regression analysis was used to assess the independent role of explanatory variables in the timing of antenatal care entry. The main outcome measure was late entry into antenatal care (gestational age at first visit after 14 weeks). With the exception of Surinamese-Hindustani women, the percentage of mothers entering antenatal care late was higher in all non-Dutch compared to Dutch mothers. We could explain differences between Turkish (OR = 0.95, CI: 0.57-1.58), Cape Verdean (OR = 1.65. CI: 0.96-2.82) and Dutch women. Other differences diminished but remained significant (Moroccan: OR = 1,74, CI: 1.07-2.85; Dutch Antillean OR 1.80, CI: 1.04-3.13). We found that non-Dutch mothers were more likely to enter antenatal care later than Dutch mothers. Because we are unable to explain fully the differences regarding Moroccan, Surinamese-Creole and Antillean women, future research should focus on differences between 1st and 2nd generation migrants, as well as on language barriers that may hinder access to adequate information about the Dutch obstetric system.