http://repub.eur.nl/res/aut/28467/ List of Publications en http://repub.eur.nl/static-eur/img/logo.png http://repub.eur.nl http://repub.eur.nl/res/pub/33191/ 2011-12-01T00:00:00Z Maternal smoking during pregnancy leads to increased risks of neonatal complications. The use of folic acid supplements might reduce the adverse effects of smoking. We examined whether folic acid supplement use modifies the associations of maternal smoking with first trimester plasma homocysteine concentrations, fetal growth characteristics, and risks of neonatal complications. The associations were studied in 6294 mothers participating in a prospective population-based cohort study in The Netherlands. Main outcomes measurements were first trimester plasma homocysteine concentrations, fetal growth characteristics, and neonatal complications, including preterm birth, low birth weight, and small-sizefor-gestational-age. Continued maternal smoking was associated with higher first trimester plasma homocysteine concentrations [difference 0.52 μmol/L (95% range = 0.20, 2.14)], lower third trimester fetal weight (difference -44 g (95% CI = -57, -31)], and birth weight [difference -148 g (95% CI = -179, -118)]. There were significant interactions between maternal smoking and folic acid supplements on all outcome measures (all P-interaction <0.040). Among mothers who continued smoking during pregnancy, those who did not use folic acid supplements had the highest risk of delivering a child with low birth weight [OR = 3.45 (95% CI = 1.25, 9.54)] compared to those who did use periconceptional folic acid supplements. No significant effects were observed for the risks of preterm birth and small-size-for-gestationalage at birth. Our results suggest that some adverse effects of maternal smoking on fetal growth and neonatal outcomes might be reduced by the use of folic acid supplements. The observed interaction seems to be mainly driven by smoking in the first trimester only. http://repub.eur.nl/res/pub/33582/ 2011-12-01T00:00:00Z Aims Blood pressure tracking can be used to examine the predictability of future values by early measurements. In a population-based prospective cohort study, among 8482 pregnant women, we examined whether blood pressure in early pregnancy tracks to third trimester and whether this tracking is influenced by maternal characteristics and is associated with the risk of gestational hypertensive disorders. Methods and resultsBlood pressure was measured in each trimester of pregnancy. Information about doctor-diagnosed pregnancy-induced hypertension and preeclampsia was obtained from medical records. Correlation coefficients between first and third trimester for systolic and diastolic blood pressure were 0.47 and 0.46, respectively. The odds ratio for staying in the highest tertile from first to third trimester for systolic blood pressure was 3.09 [95 confidence interval (CI): 2.73, 3.50] and for diastolic blood pressure 3.28 (95 CI: 2.90, 3.69). Blood pressure tracking coefficients were lower in younger, shorter, and non-European women and in women with higher gestational weight gain. Systolic and diastolic blood pressure changes from second to third trimester, but not from first to second trimester, were positively associated with the risks of pregnancy-induced hypertension and preeclampsia. ConclusionBlood pressure tracks moderately during pregnancy and is influenced by maternal characteristics. Second to third trimester increases in systolic and diastolic blood pressure are associated with an increased risk of gestational hypertensive disorders. Published on behalf of the European Society of Cardiology. http://repub.eur.nl/res/pub/34333/ 2011-12-01T00:00:00Z Introduction: Single assessment of smoking during pregnancy may lead to misclassification due to underreporting or failure of smoking cessation. We examined the percentage of mothers who were misclassified in smoking status based on single assessment, as compared with repeated assessment, and whether this misclassification leads to altered effect estimates for the associations between maternal smoking and neonatal complications. Methods: This study was performed in 5,389 mothers participating in a prospective population-based cohort study in the Netherlands. Smoking status was assessed 3 times during pregnancy using questionnaires. Information on birth weight and neonatal complications was obtained from hospital records. Results: For categorizing mothers per smoking status, Cohen's Kappa coefficient was .86 (p < .001) between single and repeated assessments. Of all mothers who reported nonsmoking or first trimester-only smoking in early pregnancy, 1.7% (70 of 4,141) and 33.7% (217 of 643), respectively, were reclassified to continued smoking based on repeated assessment. Younger, shorter lower educated mothers who had non-European ethnicity experienced more stress, consumed more alcohol, and did not use folic acid supplements had higher risk of underreporting their smoking status or failure of smoking cessation. Marginal differences were found on the associations of maternal smoking with neonatal complications between single or repeated assessment. Conclusions: Our results suggest that single assessment of smoking during pregnancy leads to underestimation of the continued smoking prevalence, especially among mothers who reported quitting smoking in first trimester. However, this underestimation does not materially change the effect estimates for the associations between maternal smoking and neonatal outcomes. http://repub.eur.nl/res/pub/33264/ 2011-10-01T00:00:00Z Researchers have suggested that maternal hypertensive disorders during pregnancy affect fetal growth. The authors examined the associations between systolic and diastolic blood pressures in different trimesters of pregnancy and both repeatedly measured fetal growth characteristics and the risks of adverse birth outcomes. The present study (2001-2005) was performed in 8,623 women who were participating in a population-based prospective cohort study from fetal life onwards. Blood pressure and fetal growth characteristics were assessed in each trimester of pregnancy. Information on hypertensive complications and adverse birth outcomes was obtained from medical records. The results suggested that higher blood pressure was associated with smaller fetal head circumference and femur length, as well as lower fetal weight from the third trimester onward. An increase in blood pressure from the second trimester to the third trimester was associated with an increased risk of adverse birth outcomes. Compared with women who did not experience hypertension during pregnancy, women with preeclampsia had increased risks of having children who were preterm (odds ratio = 5.89, 95% confidence interval: 2.63, 13.14), had a low birth weight (odds ratio = 8.94, 95% confidence interval: 6.19, 12.90), or were small for their gestational age (odds ratio = 5.03, 95% confidence interval: 3.31, 7.62). The present results suggest that higher maternal blood pressure is associated with impaired fetal growth during the third trimester of pregnancy and increased risks of adverse birth outcomes. http://repub.eur.nl/res/pub/33946/ 2011-09-01T00:00:00Z BACKGROUND: We hypothesized that hemodynamic adaptations related to pregnancy and ageing might be associated with differences in blood pressure levels during pregnancy between younger and older women. This might partly explain the increased risk of gestational hypertensive disorders with advanced maternal age. We examined the associations of maternal age with systolic and diastolic blood pressure in each trimester of pregnancy and the risks of gestational hypertensive disorders. METHODS: The study was conducted among 8,623 women participating in a population-based prospective cohort study from early pregnancy onwards. Age was assessed at enrolment. Blood pressure was measured in each trimester. Information about gestational hypertensive disorders was available from medical records. RESULTS: In second and third trimester, older maternal age was associated with lower systolic blood pressure (-0.9mmHg (95% confidence interval: -1.4, -0.3) and -0.6mmHg (95% confidence interval: -1.1, -0.02) per additional 10 maternal years, respectively). Older maternal age was associated with higher third trimester diastolic blood pressure (0.5mmHg (95% confidence interval: 0.04, 0.9) per additional 10 maternal years). Maternal age was associated with pregnancy-induced hypertension among overweight and obese women. CONCLUSION: Older maternal age is associated with lower second and third trimester systolic blood pressure, but higher third trimester diastolic blood pressure. These blood pressure differences seem to be small and within the physiological range. Maternal age is not consistently associated with the risks of gestational hypertensive disorders. Maternal body mass index might influence the association between maternal age and the risk of pregnancy-induced hypertension. http://repub.eur.nl/res/pub/33280/ 2011-08-18T00:00:00Z Objective: We sought to evaluate associations between dietary patterns and systolic blood pressure (SBP) and diastolic blood pressure during pregnancy. Study design: This was a prospective study of 3187 pregnant women. Participants completed a food-frequency questionnaire in early pregnancy. The Mediterranean dietary pattern, comprising high intake of vegetables, vegetable oils, pasta, fish, and legumes, and the Traditional dietary pattern, comprising high intake of meat and potatoes, were identified using factor analysis. Results: A higher SBP was observed among mothers with high Traditional pattern adherence. Low adherence to the Mediterranean pattern was also associated with higher SBP but only in early and mid pregnancy. A higher diastolic blood pressure throughout pregnancy was observed in mothers with high adherence to the Traditional pattern and low adherence to the Mediterranean pattern. These effect estimates were most pronounced in mid pregnancy. Conclusion: Low adherence to a Mediterranean and high adherence to a Traditional dietary pattern is associated with a higher blood pressure in pregnancy. http://repub.eur.nl/res/pub/34366/ 2011-08-01T00:00:00Z http://repub.eur.nl/res/pub/23493/ 2011-05-27T00:00:00Z Adverse maternal lifestyle habits during pregnancy are important modifiable risk factors for pregnancy complications in Western countries. Most common adverse maternal lifestyle habits include smoking, alcohol consumption, and caffeine consumption. Although not directly lifestyle related, maternal age is also considered as a modifiable risk factor for adverse pregnancy outcomes. http://repub.eur.nl/res/pub/23127/ 2011-03-01T00:00:00Z Please cite this paper as: Bakker R, Steegers E, Biharie A, Mackenbach J, Hofman A, Jaddoe V. Explaining differences in birth outcomes in relation to maternal age: the Generation R Study. BJOG 2011;118:500-509. 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. http://repub.eur.nl/res/pub/27814/ 2010-11-01T00:00:00Z Objective: Smoking during pregnancy is a risk factor for various adverse birth outcomes but lowers the risk of preeclampsia. Cardiovascular adaptations might underlie these associations. We examined the associations of smoking in different trimesters of pregnancy with repeatedly measured blood pressure and the risks of preeclampsia and pregnancy-induced hypertension in a low-risk population-based cohort of 7106 pregnant women. Methods: This study was embedded in a population-based prospective cohort study from early pregnancy onwards. Smoking and systolic and diastolic blood pressures were assessed by questionnaires and physical examinations in each trimester of pregnancy. Information about preeclampsia and pregnancy-induced hypertension was obtained from medical records. Results: Compared to nonsmoking women, both first-trimester-only and continued smoking were associated with a steeper increase for systolic blood pressure and a lowest mid-pregnancy level and steeper increase thereafter for diastolic blood pressure throughout pregnancy. We did not find any significant associations in risk of preeclampsia for first-trimester-only smoking (odds ratio of 1.28, 95% confidence interval 0.74, 2.21) and continued smoking (odds ratio of 0.83, 95% confidence interval 0.50, 1.36), respectively. Conclusions: Our results suggest that both first-trimester-only and continued smoking are associated with persistent maternal cardiovascular adaptations during pregnancy. Strategies for prevention of smoking during pregnancy should be focused on the preconception period. The effects of early and late-pregnancy smoking on the risk of preeclampsia should be further explored. Our results should be carefully interpreted to the general population of pregnant women. http://repub.eur.nl/res/pub/27537/ 2010-06-01T00:00:00Z Background: Caffeine is a widely used and accepted pharmacologically active substance. The effect of caffeine intake during pregnancy on fetal growth and development is still unclear. Objective: We examined the associations of maternal caffeine intake, on the basis of coffee and tea consumption, with fetal growth characteristics measured in each trimester of pregnancy and the risks of adverse birth outcomes. Design: Associations were studied in 7346 pregnant women participating in a population-based prospective cohort study from early pregnancy onward in the Netherlands (2001-2005). Caffeine intake in the first, second, and third trimesters was on the basis of coffee and tea consumption and was assessed by questionnaires. Fetal growth characteristics were repeatedly measured by ultrasound. Information about birth outcomes was obtained from hospital records. Results: We observed no consistent associations of caffeine intake with fetal head circumference or estimated fetal weight in any trimester. Higher caffeine intake was associated with smaller first-trimester crown-rump length, second- and third-trimester femur length, and birth length (P for trend <0.05). Offspring of mothers who consumed ≥6 caffeine units/d tended to have increased risks of small-for-gestational-age infants at birth. Conclusions: Our results suggest that caffeine intake of ≥6 units/d during pregnancy is associated with impaired fetal length growth. Caffeine exposure might preferentially adversely affect fetal skeletal growth. Further studies are needed to assess these associations in non-European populations and to assess the postnatal consequences. http://repub.eur.nl/res/pub/21228/ 2010-03-01T00:00:00Z Background: Excessive alcohol consumption during pregnancy has adverse effects on fetal growth and development. Less consistent associations have been shown for the associations of light-to-moderate maternal alcohol consumption during pregnancy with health outcomes in the offspring. Therefore, we examined the associations of light-to-moderate maternal alcohol consumption with various fetal growth characteristics measured in different periods of pregnancy. Methods: This study was based on 7333 pregnant women participating in a population-based cohort study. Alcohol consumption habits and fetal growth were assessed in early (gestational age <17.9 weeks), mid- (gestational age 18-24.9 weeks) and late pregnancy (gestational age ≥25 weeks). We assessed the effects of different categories of alcohol consumption (no; less than one drink per week; one to three drinks per week; four to six drinks per week; one drink per day and two to three drinks per day) on repeatedly measured fetal head circumference, abdominal circumference and femur length. Results: In total, 37% of all mothers continued alcohol consumption during pregnancy, of whom the majority used less than three drinks per week. We observed no differences in growth rates of fetal head circumference, abdominal circumference or femur length between mothers with and without continued alcohol consumption during pregnancy. Compared with mothers without alcohol consumption, mothers with continued alcohol consumption during pregnancy had an increased fetal weight gain [difference 0.61 g (95% confidence interval: 0.18, 1.04) per week]. Cross-sectional analyses in mid- and late pregnancy showed no consistent associations between the number of alcoholic consumptions and fetal growth characteristics. All analyses were adjusted for potential confounders. Conclusions: Light-to-moderate maternal alcohol consumption during pregnancy does not adversely affect fetal growth characteristics. Further studies are needed to assess whether moderate alcohol consumption during pregnancy influences organ growth and function in postnatal life. http://repub.eur.nl/res/pub/24819/ 2009-06-01T00:00:00Z Objective We aimed to examine the associations of maternal anthropometrics with fetal weight measured in different periods of pregnancy and with birth outcomes. Design Population-based birth cohort study. Setting Data of pregnant women and their children in Rotterdam, the Netherlands. Population In 8541 mothers, height, prepregnancy body mass index (BMI) and gestational weight gain were available. Methods Fetal growth was measured by ultrasound in mid- and late pregnancy. Regression analyses were used to assess the impact of maternal anthropometrics on fetal weight and birth outcomes. Main outcome measures Fetal weight and birth outcomes: weight (grams) and the risks of small (<5th percentile) and large (>95th percentile) size for gestational age at birth. Results Maternal BMI in pregnancy was positively associated with estimated fetal weight during pregnancy. The effect estimates increased with advancing gestational age. All maternal anthropometrics were positively associated with fetal size (P-values for trend <0.01). Mothers with both their prepregnancy BMI and gestational weight gain quartile in the lowest and highest quartiles showed the highest risks of having a small and large size for gestational age child at birth, respectively. The effect of prepregnancy BMI was strongly modified by gestational weight gain. Conclusions Fetal growth is positively affected by maternal BMI during pregnancy. Maternal height, prepregnancy BMI and gestational weight gain are all associated with increased risks of small and large size for gestational age at birth in the offspring, with an increased effect when combined. http://repub.eur.nl/res/pub/29212/ 2008-12-01T00:00:00Z A previous analysis of the Project Viva cohort (eastern Massachusetts, 1999-2002 recruitment) found an association between higher second-trimester supplemental maternal calcium intake and lower systolic blood pressure in offspring at 6 months. The authors analyzed 5,527 systolic blood pressure measurements from 1,173 mother-child pairs from this same cohort when the children were aged 3 years. They estimated the change in offspring blood pressure for a 500-mg difference in maternal total, dietary-only, and supplemental-only calcium intake during the first 2 trimesters of pregnancy. Mean daily total calcium intake was 1,311 mg (standard deviation, 421) in the first trimester and 1,440 mg (standard deviation, 386) in the second trimester. Mean systolic blood pressure of the offspring at age 3 years was 92.1 mm Hg (standard deviation, 10.3). None of the maternal calcium intake measures during the first and second trimesters was associated with systolic blood pressure in the offspring. For example, for each 500-mg increment in maternal total elemental calcium intake in the second trimester, child's 3-year systolic blood pressure was 0.1 mm Hg lower (95% confidence interval: -0.9, 0.6). Maternal calcium intake during pregnancy was not associated with offspring blood pressure at the age of 3 years. http://repub.eur.nl/res/pub/35992/ 2007-12-01T00:00:00Z The Generation R Study is a population-based prospective cohort study from fetal life until young adulthood. The study is designed to identify early environmental and genetic causes of normal and abnormal growth, development and health from fetal life until young adulthood. In total, 9,778 mothers were enrolled in the study. Prenatal and postnatal data collection is conducted by physical examinations, questionnaires, interviews, ultrasound examinations and biological samples. Major efforts have been conducted for collecting biological specimens including DNA, blood for phenotypes and urine samples. In this paper, the collection, processing and storage of these biological specimens are described. Together with detailed phenotype measurements, these biological specimens form a unique resource for epidemiological studies focused on environmental exposures, genetic determinants and their interactions in relation to growth, health and development from fetal life onwards. http://repub.eur.nl/res/pub/36577/ 2007-10-01T00:00:00Z Purpose: To examine the associations of alcohol consumption in different periods of pregnancy with the risks of low birth weight and preterm birth. Methods: This study was based on 7141 subjects participating in a population-based prospective cohort study from early pregnancy. Alcohol consumption was assessed in early, mid, and late pregnancy. Birth outcomes were birth weight in grams, low birth weight (<2500 g), small size for gestational age at birth (< -2 standard deviation scores) and preterm birth (gestational age <37 weeks). Results: Overall, alcohol consumption during pregnancy was not associated with adverse birth outcomes. However, dose-response analyses showed tendencies toward adverse effects of average consumption of 1 or more alcoholic drinks per day in early pregnancy on birth weight (difference -129 g [95% confidence interval (CI): -271, 12]), low birth weight (adjusted odds ratio [aOR] 4.81 [95% CI: 1.10, 21.08]), small size for gestational age at birth (aOR 1.45 [95% CI: 0.33, 6.44]) and preterm birth (aOR 2.51 [95% CI: 0.92, 6.81]). Similar effects were found in late pregnancy. Conclusion: Average consumption of one or more but not less than one alcoholic drink per day in early or late pregnancy seems to be associated with adverse birth outcomes in the offspring.