Small Size For Gestational Age Research Articles

Prenatal Health, Educational Attainment, and Intergenerational Inequality: The Northern Finland Birth Cohort 1966 Study

In this article, we study the effects of prenatal health on educational attainment and on the reproduction of family background inequalities in education. Using Finnish birth cohort data, we analyze several maternal and fetal health variables, many of which have not been featured in the literature on long-term socioeconomic effects of health despite the effects of these variables on birth and short-term health outcomes. We find strong negative effects of mother's prenatal smoking on educational attainment, which are stronger if the mother smoked heavily but are not significant if she quit during the first trimester. Anemia during pregnancy is also associated with lower levels of attained education. Other indicators of prenatal health (pre-pregnancy obesity, mother's antenatal depressed mood, hypertension and preeclampsia, early prenatal care visits, premature birth, and small size for gestational age) do not predict educational attainment. Our measures explain little of the educational inequalities by parents' class or education. However, smoking explains 12%-and all health variables together, 19%-of the lower educational attainment of children born to unmarried mothers. Our findings point to the usefulness of proximate health measures in addition to general ones. They also point to the potentially important role played by early health in intergenerational processes.

Neighborhood Inequalities in Adverse Pregnancy Outcomes in an Urban Setting in Spain: A Multilevel Approach

The aim of the present study was to describe socioeconomic inequalities in low birth weight (LBW), premature birth (PM) and small size for gestational age at birth (SGA) between 2000 and 2005 in Barcelona, Spain, jointly evaluating the effect of mother's country of origin, and neighborhood of residence socioeconomic level measured using unemployment and educational level. We performed a cross-sectional study of births to mothers aged 12-49 years who were residents in the city of Barcelona in 2000-2005, analyzing adverse pregnancy outcomes (n = 61,676). Weighted multilevel logistic regression models were fitted with individual data on level 1 and neighborhood data on level 2, to obtain adjusted odds ratios (aOR) with 95% confidence intervals and residual variance. Individually, pregnancy outcomes are more favorable in births to older mothers and to mothers from Maghrib and Central and South America than from developed countries (including Spain) or from other developing countries. After adjusting for individual variables, poor pregnancy outcomes were associated with poor neighborhoods (more unemployment was associated to LBW: aOR = 1.56; PM aOR = 1.51; SGA aOR = 1.66). The same trend was observed for associations with illiteracy rate. The present study shows that there are socioeconomic inequalities in adverse pregnancy outcomes in the city of Barcelona. One of the main challenges in perinatal health continues to be the reduction of adverse pregnancy outcomes in the city.

Características epidemiológicas e óbitos de prematuros atendidos em hospital de referência para gestante de alto risco

ObjectiveTo analyze the process of care provided to premature infants in a neonatal intensive care unit and the factors associated with their mortality. MethodsCross-sectional retrospective study of premature infants in an intensive care unit between 2008 and 2010. The characteristics of the mothers and premature infants were described, and a bivariate analysis was performed on the following characteristics: the study period and the "death" outcome (hospital, neonatal and early) using Pearson's chi-square test, Fisher's exact test or a chi-square test for linear trends. Bivariate and multivariable logistic regression analyses were performed using a stepwise backward logistic regression method between the variables with p<0.20 and the "death" outcome. A p value <0.05 was considered to be significant. ResultsIn total, 293 preterm infants were studied. Increased access to complementary tests (transfontanellar ultrasound and Doppler echocardiogram) and breastfeeding rates were indicators of improving care. Mortality was concentrated in the neonatal period, especially in the early neonatal period, and was associated with extreme prematurity, small size for gestational age and an Apgar score <7 at 5 minutes after birth. The late-onset sepsis was also associated with a greater chance of neonatal death, and antenatal corticosteroids were protective against neonatal and early deaths. ConclusionsAlthough these results are comparable to previous findings regarding mortality among premature infants in Brazil, the study emphasizes the need to implement strategies that promote breastfeeding and reduce neonatal mortality and its early component.

Factors associated with mortality and length of stay in hospitalised neonates in Eritrea, Africa: a cross-sectional study

ObjectiveTo determine the factors associated with mortality in a hospitalised cohort of infants in Asmara, Eritrea.DesignRetrospective cross-sectional review of all 2006 admissions to a specialised neonatal intensive care unit. Data...

Individually customised fetal weight charts derived from ultrasound measurements: the Generation R Study

Maternal and fetal characteristics are important determinants of fetal growth potential, and should ideally be taken into consideration when evaluating fetal growth variation. We developed a model for individually customised growth charts for estimated fetal weight, which takes into account physiological maternal and fetal characteristics known at the start of pregnancy. We used fetal ultrasound data of 8,162 pregnant women participating in the Generation R Study, a prospective, population-based cohort study from early pregnancy onwards. A repeated measurements regression model was constructed, using backward selection procedures for identifying relevant maternal and fetal characteristics. The final model for estimating expected fetal weight included gestational age, fetal sex, parity, ethnicity, maternal age, height and weight. Using this model, we developed individually customised growth charts, and their corresponding standard deviations, for fetal weight from 18 weeks onwards. Of the total of 495 fetuses who were classified as small size for gestational age (<10th percentile) when fetal weight was evaluated using the normal population growth chart, 80 (16%) were in the normal range when individually customised growth charts were used. 550 fetuses were classified as small size for gestational age using individually customised growth charts, and 135 of them (25%) were classified as normal if the unadjusted reference chart was used. In conclusion, this is the first study using ultrasound measurements in a large population-based study to fit a model to construct individually customised growth charts, taking into account physiological maternal and fetal characteristics. These charts might be useful for use in epidemiological studies and in clinical practice.Electronic supplementary materialThe online version of this article (doi:10.1007/s10654-011-9629-7) contains supplementary material, which is available to authorized users.

Biomonitoring of bisphenol A concentrations in maternal and umbilical cord blood in regard to birth outcomes and adipokine expression: a birth cohort study in Taiwan.

BackgroundBisphenol A (BPA) is a sealant and flux of plastic materials and has been determined to be an endocrine-disrupting chemical. Prenatal exposure to BPA can lead to substantial adverse effects on fetal growth and development. This study was conducted to assess BPA concentration in pregnant women and umbilical cord blood, and to investigate whether maternal BPA exposure affected fetal outcomes including lower birth weight (LBW), smaller size for gestational age (SGA), and high leptin (HLP) and low adiponectin (LAD) secretion.MethodsWe measured the BPA levels of maternal blood (n = 97) and umbilical cord blood (n = 97) with a high-performance liquid chromatography/UV detector. The protein secretion of leptin and adiponectin were separately determined using enzyme-linked immunosorbent assay. A logistic regression was performed to estimate the effects of maternal exposure to BPA on LBW, SGA, and adverse action of adipokines in newborns.ResultsThe geometric means of BPA concentration in maternal blood and fetal cord blood were 2.5 ng/ml and 0.5 ng/ml, respectively. Elevated risks of LBW (OR 2.42, 95% confidence interval (CI) 1.72-3.36), SGA (OR 2.01, 95% CI 1.39-3.01), and adverse action of leptin (OR 1.67, 95% CI 1.12-2.25) and adiponectin (OR 1.25, 95% CI 1.52-3.97) were observed in male neonates in the highest quartile of maternal BPA exposure.ConclusionsElevated prenatal BPA exposure increased the risk of LBW, SGA, and adverse actions of adipokines in neonates, especially in male infants. These results provide further evidence that maternal exposure is correlated with adverse birth outcomes.

DOES COMMUNITY VULNERABILITY AMPLIFY THE RELATIONSHIP BETWEEN TRAFFIC EXPOSURE AND ADVERSE BIRTH OUTCOMES? A UNIVERSITY-REGULATORY RESEARCH COLLABORATIVE ON ENVIRONMENTAL HEALTH INEQUALITIES

Background: Studies within the United States and elsewhere have identified a relationship between air pollution, preterm birth, and low birth weight Spatial variation in air pollutant concentrations in urban areas have been attributed to traffic emissions, and documented for several pollutants, including nitrogen dioxide, ultrafine particles, and particulates. Epidemiological studies have linked residential proximity to traffic, such as distance to major roadways or traffic density near specific locations with adverse perinatal outcomes, including increased risk of preterm birth, small size for gestational age, and low birth weight. However, there remains a paucity of research on traffic density and birth outcomes, and few studies have examined effect modification by area-level SES measures. Methods: We build on existing work by examining links between traffic density and risk of preterm birth and effects on average birth weight in a large sample of singleton births (~1.5 million) in California between 2001-2005. We also assessed the potentially synergistic and confounding effects of area-level SES measures. Distance weighted traffic volume measures were geocoded to the mother’s address at the time of birth. Results: Results indicate a decrease in average birth weight with increasing traffic burden [-10.4 (95% CI: -7.1, -13.6)] in the highest versus lowest quintile of traffic density] and a higher risk of preterm birth with higher traffic density [1.04 (95% CI: 1.01, 1.07) highest versus lowest quintile of traffic density]. Effect estimates remained robust after controlling for maternal and neighborhood level SES variables. Although we did not observe effect modification by neighborhood-level SES, we did observe stronger effects for birth weight in areas characterized by higher levels of racial residential segregation. Conclusion: Results suggest that studies applying source-specific measures of ambient pollution, such as traffic density, can elucidate policy-relevant opportunities for reducing community exposure to multiple pollutants.

Adiposidad central en niños que nacieron con poco o con excesivo peso para su edad gestacional

Objective: To evaluate body composition differences between children that were born small (SGA) or large for gestational age (LGA) compared with their counterparts born adequate for gestational age (AGA). Methods: Body composition was assessed in 124 healthy Caucasian children (50% girls) aged 6-10, classified according to their birth weight for gestational age as AGA, SGA and LGA. Fat mass (FM), percentage of FM, lean mass (LM), bone mineral content (BMC) and bone mineral density were measured by dual-energy X-ray absorptiometry (DXA) in the whole body and at different body regions. Results: LM (adjusted for age and sex) and total BMC (adjusted for age, sex and weight) were both significantly higher in LGA children and lower in SGA when compared with those born AGA. After adjustments for height, LM and BMC differences between groups were not significant. In SGA children, truncal (P<0.05) and abdominal fatness (P<0.01) were higher when compared with both AGA and LGA children, after adjustments for age, sex and height. There were no differences in the percentage of total and central FM between children born LGA and AGA. Conclusions: During childhood, children born SGA had higher central adiposity regardless of their body size. Children born LGA seem to have a higher body size but with harmonic body composition and adequate body fat distribution. Small size for gestational age at birth could programme excess abdominal fat deposition in children, which is a major factor for the clustering of cardiovascular disease risk factors defining the metabolic syndrome.

Central adiposity in children born small and large for gestational age.

To evaluate body composition differences between children that were born small (SGA) or large for gestational age (LGA) compared with their counterparts born adequate for gestational age (AGA). Body composition was assessed in 124 healthy Caucasian children (50% girls) aged 6-10, classified according to their birth weight for gestational age as AGA, SGA and LGA. Fat mass (FM), percentage of FM, lean mass (LM), bone mineral content (BMC) and bone mineral density were measured by dual-energy X-ray absorptiometry (DXA) in the whole body and at different body regions. LM (adjusted for age and sex) and total BMC (adjusted for age, sex and weight) were both significantly higher in LGA children and lower in SGA when compared with those born AGA. After adjustments for height, LM and BMC differences between groups were not significant. In SGA children, truncal (P<0.05) and abdominal fatness (P<0.01) were higher when compared with both AGA and LGA children, after adjustments for age, sex and height. There were no differences in the percentage of total and central FM between children born LGA and AGA. During childhood, children born SGA had higher central adiposity regardless of their body size. Children born LGA seem to have a higher body size but with harmonic body composition and adequate body fat distribution. Small size for gestational age at birth could programme excess abdominal fat deposition in children, which is a major factor for the clustering of cardiovascular disease risk factors defining the metabolic syndrome.

Air Pollution Exposure During Pregnancy, Ultrasound Measures of Fetal Growth, and Adverse Birth Outcomes: A Prospective Cohort Study

Background: Air pollution exposure during pregnancy might have trimester-specific effects on fetal growth.Objective: We prospectively evaluated the associations of maternal air pollution exposure with fetal growth characteristics and adverse birth outcomes in 7,772 subjects in the Netherlands.Methods: Particulate matter with an aerodynamic diameter < 10 μm (PM10) and nitrogen dioxide (NO2) levels were estimated using dispersion modeling at the home address. Fetal head circumference, length, and weight were estimated in each trimester by ultrasound. Information on birth outcomes was obtained from medical records.Results: In cross-sectional analyses, NO2 levels were inversely associated with fetal femur length in the second and third trimester, and PM10 and NO2 levels both were associated with smaller fetal head circumference in the third trimester [–0.18 mm, 95% confidence interval (CI): –0.24, –0.12 mm; and –0.12 mm, 95% CI: –0.17, –0.06 mm per 1-μg/m3 increase in PM10 and NO2, respectively]. Average PM10 and NO2 levels during pregnancy were not associated with head circumference and length at birth or neonatally, but were inversely associated with birth weight (–3.6 g, 95% CI: –6.7, –0.4 g; and –3.4 g, 95% CI: –6.2, –0.6 g, respectively). Longitudinal analyses showed similar patterns for head circumference and weight, but no associations with length. The third and fourth quartiles of PM10 exposure were associated with preterm birth [odds ratio (OR) = 1.40, 95% CI: 1.03, 1.89; and OR = 1.32; 95% CI: 0.96, 1.79, relative to the first quartile]. The third quartile of PM10 exposure, but not the fourth, was associated with small size for gestational age at birth (SGA) (OR = 1.38; 95% CI: 1.00, 1.90). No consistent associations were observed for NO2 levels and adverse birth outcomes.Conclusions: Results suggest that maternal air pollution exposure is inversely associated with fetal growth during the second and third trimester and with weight at birth. PM10 exposure was positively associated with preterm birth and SGA.

Major Risk Factors for Stillbirth in High-Income Countries: A Systematic Review and Meta-Analysis

Summary Background Stillbirth rates in high-income countries have shown little or no improvement over the past two decades. Prevention strategies that target risk factors could be important in rate reduction. This systematic review and meta-analysis was done to identify priority areas for stillbirth prevention relevant to those countries. Methods Population-based studies addressing risk factors for stillbirth were identified through database searches. The factors most frequently reported were identified and selected according to whether they could potentially be reduced through lifestyle or medical intervention. The numbers attributable to modifiable risk factors were calculated from data relating to the five high-income countries with the highest numbers of stillbirths and where all the data required for analysis were available. Odds ratios were calculated for selected risk factors, from which population-attributable risk (PAR) values were calculated. Findings Of 6963 studies initially identified, 96 population-based studies were included. Maternal overweight and obesity (body-mass index >25 kg/m 2 ) was the highest ranking modifiable risk factor, with PARs of 8–18% across the five countries and contributing to around 8000 stillbirths (≥22 weeks' gestation) annually across all high-income countries. Advanced maternal age (>35 years) and maternal smoking yielded PARs of 7–11% and 4–7%, respectively, and each year contribute to more than 4200 and 2800 stillbirths, respectively, across all high-income countries. In disadvantaged populations maternal smoking could contribute to 20% of stillbirths. Primiparity contributes to around 15% of stillbirths. Of the pregnancy disorders, small size for gestational age and abruption are the highest PARs (23% and 15%, respectively), which highlights the notable role of placental pathology in stillbirth. Pre-existing diabetes and hypertension remain important contributors to stillbirth in such countries. Interpretation The raising of awareness and implementation of effective interventions for modifiable risk factors, such as overweight, obesity, maternal age, and smoking, are priorities for stillbirth prevention in high-income countries. Funding The Stillbirth Foundation Australia, the Department of Health and Ageing, Canberra, Australia, and the Mater Foundation, Brisbane, Australia.

C-reactive protein levels in early pregnancy, fetal growth patterns, and the risk for neonatal complications: the Generation R Study

We sought to examine the associations of maternal C-reactive protein (CRP) levels with fetal growth and the risks of neonatal complications. CRP levels were measured in early pregnancy in 6016 women. Main outcome measures were fetal growth in each trimester and neonatal complications. As compared to the reference group (CRP levels<5 mg/L), elevated maternal CRP levels (≥25 mg/L) were associated with lower estimated fetal weight in third trimester and lower weight at birth (differences: -29 g, 95% confidence interval [CI], -58 to 0 and -128 g, 95% CI, -195 to -60, respectively). Elevated maternal CRP levels were also associated with an increased risk of a small size for gestational age in the offspring (adjusted odds ratio, 2.94; 95% CI, 1.61-5.36). Maternal CRP levels in early pregnancy are associated with fetal growth restriction and increased risks of neonatal complications.

Major risk factors for stillbirth in high-income countries: a systematic review and meta-analysis

Stillbirth rates in high-income countries have shown little or no improvement over the past two decades. Prevention strategies that target risk factors could be important in rate reduction. This systematic review and meta-analysis was done to identify priority areas for stillbirth prevention relevant to those countries. Population-based studies addressing risk factors for stillbirth were identified through database searches. The factors most frequently reported were identified and selected according to whether they could potentially be reduced through lifestyle or medical intervention. The numbers attributable to modifiable risk factors were calculated from data relating to the five high-income countries with the highest numbers of stillbirths and where all the data required for analysis were available. Odds ratios were calculated for selected risk factors, from which population-attributable risk (PAR) values were calculated. Of 6963 studies initially identified, 96 population-based studies were included. Maternal overweight and obesity (body-mass index >25 kg/m(2)) was the highest ranking modifiable risk factor, with PARs of 8-18% across the five countries and contributing to around 8000 stillbirths (≥22 weeks' gestation) annually across all high-income countries. Advanced maternal age (>35 years) and maternal smoking yielded PARs of 7-11% and 4-7%, respectively, and each year contribute to more than 4200 and 2800 stillbirths, respectively, across all high-income countries. In disadvantaged populations maternal smoking could contribute to 20% of stillbirths. Primiparity contributes to around 15% of stillbirths. Of the pregnancy disorders, small size for gestational age and abruption are the highest PARs (23% and 15%, respectively), which highlights the notable role of placental pathology in stillbirth. Pre-existing diabetes and hypertension remain important contributors to stillbirth in such countries. The raising of awareness and implementation of effective interventions for modifiable risk factors, such as overweight, obesity, maternal age, and smoking, are priorities for stillbirth prevention in high-income countries. The Stillbirth Foundation Australia, the Department of Health and Ageing, Canberra, Australia, and the Mater Foundation, Brisbane, Australia.

Maternal multiple micronutrient supplementation and pregnancy outcomes in developing countries: meta-analysis and meta-regression

To systematically review randomized controlled trials comparing the effect of supplementation with multiple micronutrients versus iron and folic acid on pregnancy outcomes in developing countries. MEDLINE and EMBASE were searched. Outcomes of interest were birth weight, low birth weight, small size for gestational age, perinatal mortality and neonatal mortality. Pooled relative risks (RRs) were estimated by random effects models. Sources of heterogeneity were explored through subgroup meta-analyses and meta-regression. Multiple micronutrient supplementation was more effective than iron and folic acid supplementation at reducing the risk of low birth weight (RR: 0.86, 95% confidence interval, CI: 0.79-0.93) and of small size for gestational age (RR: 0.85; 95%CI: 0.78-0.93). Micronutrient supplementation had no overall effect on perinatal mortality (RR: 1.05; 95% CI: 0.90-1.22), although substantial heterogeneity was evident (I(2) = 58%; P for heterogeneity = 0.008). Subgroup and meta-regression analyses suggested that micronutrient supplementation was associated with a lower risk of perinatal mortality in trials in which > 50% of mothers had formal education (RR: 0.93; 95% CI: 0.82-1.06) or in which supplementation was initiated after a mean of 20 weeks of gestation (RR: 0.88; 95% CI: 0.80-0.97). Maternal education or gestational age at initiation of supplementation may have contributed to the observed heterogeneous effects on perinatal mortality. The safety, efficacy and effective delivery of maternal micronutrient supplementation require further research.

Maternal smoking during pregnancy and subcutaneous fat mass in early childhood. The Generation R Study

Maternal smoking during pregnancy increases the risk of obesity in the offspring. Not much is known about the associations with other measures of body composition. We assessed the associations of maternal smoking during pregnancy with the development of subcutaneous fat mass measured as peripheral and central skinfold thickness measurements in early childhood, in a population-based prospective cohort study from early fetal life onward in the city of Rotterdam, The Netherlands. The study was performed in 907 mothers and their children at the ages of 1.5, 6 and 24 months. As compared to non-smoking mothers, mothers who continued smoking during pregnancy were more likely to have a younger age and a lower educational level. Their children had a lower birth weight, higher risk of small size for gestational age and were breastfed for a shorter duration (P-values <0.01). We did not observe differences in peripheral, central and total subcutaneous fat mass between the offspring of non-smoking mothers, mothers who smoked in first trimester only and mothers who continued smoking during pregnancy (P > 0.05). Also, the reported number of cigarettes smoked by mothers in both first and third trimester of pregnancy were not associated with peripheral, central and total subcutaneous fat mass in the offspring at the ages of 1.5, 6 and 24 months. Our findings suggest that fetal exposure to cigarette smoke during pregnancy does not influence subcutaneous fat mass in early childhood. Follow-up studies are needed in children at older ages and to identify associations of maternal smoking during pregnancy with other measures of body composition.

Vitamin C and E Supplementation Does Not Reduce the Risk of Superimposed PE in Pregnancy

Background. Oxidative stress could play a role in the development of preeclampsia. There is some evidence to suggest that vitamin C and E supplements can reduce the risk of the disorder. We hypothesized its beneficial role in a group of pregnant women with essential hypertension. Methods. In this randomized controlled trial, we enrolled 50 pregnant women with essential hypertension. We assigned the women 1000 mg vitamin C and 400 IU natural vitamin E (RRR α tocopherol; n = 25), daily from the second trimester of pregnancy until delivery or no supplementation (n = 25). Our primary endpoint was development of superimposed preeclampsia, and main secondary endpoints were aggravation of hypertension, need for admission, need to increase antihypertensive drugs, and small size for gestational age (<fifth customized birthweight centile). Results. We analyzed 50 women who completed the study. The incidence of superimposed preeclampsia was similar in vitamin and control groups (8% [n = 2] vs 12% [n = 3], p = 1.000). Vitamin C and E supplementation also did not prevent aggravation of hypertension in group of women who took it (12% [n = 3] vs 32% [n = 8], p = 0.172). Small size for gestational age babies did not differ between groups (4% [n = 2] vs 6% [n = 3], p = 1.000). Conclusion. Vitamin C and E supplementation does not prevent development of superimposed preeclampsia in women with essential hypertension. Our results did not show any significant benefit of vitamin supplementation. There was some trend in lessening of hypertensive complications of pregnancy. Our results failed to find any correlation between development of superimposed preeclampsia and oxidative stress.

Risk Factors and Outcomes Associated With First-Trimester Fetal Growth Restriction

ABSTRACT Exposure of the fetus to an adverse environment may result in developmental adaptations that lead to fetal growth restriction. It has been suggested that fetal growth restriction may increase the risk of metabolic and cardiovascular diseases and other adverse outcomes in adulthood. Previous studies have shown that first trimester fetal growth restriction increased the risks of low birth weight and small size for gestational age. The effects of maternal lifestyle habits and physical characteristics on first trimester growth and postnatal outcomes are not known. This population-based prospective cohort study investigated the associations of first trimester growth restriction with adverse birth outcomes and postnatal outcomes in early childhood. The effect of several maternal physical characteristics and lifestyle habits on postnatal outcomes was also investigated. A self-administered questionnaire was completed by the mothers at enrollment. First trimester fetal growth in singleton mothers was assessed sonographically by measuring fetal crown rump length between the gestational age of 10 weeks 0 days and 13 weeks 6 days, and then performing follow-up growth scans in the second and third trimesters. The primary birth outcomes examined were preterm birth, low birth weight, and small size for gestational age at birth. Postnatal outcomes were studied up to the age of 2 years. Multivariate analysis showed that maternal age was positively associated with fetal crown rump length; the difference was 0.79 mm (95% confidence interval [CI]: 0.41–1.18) per 1 standard deviation (4.68 maternal years of age) increase. Both diastolic blood pressure and the hematocrit were negatively associated with first trimester crown to rump growth (shorter length) (differences, −0.40 mm; 95% CI: −0.74 to −0.06, and −0.52 mm; 95% CI: −0.90 to −0.14 per standard deviation increase, respectively). Mothers who smoked and did not use folic acid supplements had shorter crown rump lengths than nonsmoking mothers who used folic acid supplements; the difference was 3.84 mm; 95% CI: −5.71 to −1.98. In comparison to normal first trimester growth, restricted first trimester growth was associated with increased risks of prematurity (4.0% vs. 7.2%; adjusted odds ratio [OR]: 2.12; 95% CI: 1.24–3.61), small size for the gestational age at birth (4.0% vs.10.6%; OR: 2.64; 95% CI: 1.64–4.25), and low birth weight (3.5% vs. 7.5%; OR: 2.42; 95% CI: 1.41–4.16). Over the first 2 years of postnatal growth, each standard deviation decrease in first trimester fetal crown rump length was associated with an accelerated growth rate in weight and height; the increase in the standard deviation score was 0.139 per 2 years; 95% CI: 0.097 to 0.181. These findings demonstrate that first trimester fetal growth is independently associated with a number of maternal physical characteristics and lifestyle habits. Early fetal growth restriction is also associated with an increased risk of adverse birth outcomes and accelerated growth rates in early childhood.

Early fetal growth: concepts and pitfalls

Early fetal growth: concepts and pitfalls

Risk Factors and Outcomes Associated With First-Trimester Fetal Growth Restriction

Adverse environmental exposures lead to developmental adaptations in fetal life. The influences of maternal physical characteristics and lifestyle habits on first-trimester fetal adaptations and the postnatal consequences are not known. To determine the risk factors and outcomes associated with first-trimester growth restriction. Prospective evaluation of the associations of maternal physical characteristics and lifestyle habits with first-trimester fetal crown to rump length in 1631 mothers with a known and reliable first day of their last menstrual period and a regular menstrual cycle. Subsequently, we assessed the associations of first-trimester fetal growth restriction with the risks of adverse birth outcomes and postnatal growth acceleration until the age of 2 years. The study was based in Rotterdam, The Netherlands. Mothers were enrolled between 2001 and 2005. First-trimester fetal growth was measured as fetal crown to rump length by ultrasound between the gestational age of 10 weeks 0 days and 13 weeks 6 days. Main birth outcomes were preterm birth (gestational age <37 weeks), low birth weight (<2500 g), and small size for gestational age (lowest fifth birth centile). Postnatal growth was measured until the age of 2 years. In the multivariate analysis, maternal age was positively associated with first-trimester fetal crown to rump length (difference per maternal year of age, 0.79 mm; 95% confidence interval [CI], 0.41 to 1.18 per standard deviation score increase). Higher diastolic blood pressure and higher hematocrit levels were associated with a shorter crown to rump length (differences, -0.40 mm; 95% CI, -0.74 to -0.06 and -0.52 mm; 95% CI, -0.90 to -0.14 per standard deviation increase, respectively). Compared with mothers who were nonsmokers and optimal users of folic acid supplements, those who both smoked and did not use folic acid supplements had shorter fetal crown to rump lengths (difference, -3.84 mm; 95% CI, -5.71 to -1.98). Compared with normal first-trimester fetal growth, first-trimester growth restriction was associated with increased risks of preterm birth (4.0% vs 7.2%; adjusted odds ratio [OR], 2.12; 95% CI, 1.24 to 3.61), low birth weight (3.5% vs 7.5%; adjusted OR, 2.42; 95% CI, 1.41 to 4.16), and small size for gestational age at birth (4.0% vs 10.6%; adjusted OR, 2.64; 95% CI, 1.64 to 4.25). Each standard deviation decrease in first-trimester fetal crown to rump length was associated with a postnatal growth acceleration until the age of 2 years (standard deviation score increase, 0.139 per 2 years; 95% CI, 0.097 to 0.181). Maternal physical characteristics and lifestyle habits were independently associated with early fetal growth. First-trimester fetal growth restriction was associated with an increased risk of adverse birth outcomes and growth acceleration in early childhood.

Residential traffic exposure and pregnancy-related outcomes: a prospective birth cohort study

BackgroundThe effects of ambient air pollution on pregnancy outcomes are under debate. Previous studies have used different air pollution exposure assessment methods. The considerable traffic-related intra-urban spatial variation needs to be considered in exposure assessment. Residential proximity to traffic is a proxy for traffic-related exposures that takes into account within-city contrasts.MethodsWe investigated the association between residential proximity to traffic and various birth and pregnancy outcomes in 7,339 pregnant women and their children participating in a population-based cohort study. Residential proximity to traffic was defined as 1) distance-weighted traffic density in a 150 meter radius, and 2) proximity to a major road. We estimated associations of these exposures with birth weight, and with the risks of preterm birth and small size for gestational age at birth. Additionally, we examined associations with pregnancy-induced hypertension, (pre)eclampsia, and gestational diabetes.ResultsThere was considerable variation in distance-weighted traffic density. Almost fifteen percent of the participants lived within 50 m of a major road. Residential proximity to traffic was not associated with birth and pregnancy outcomes in the main analysis and in various sensitivity analyses.ConclusionsMothers exposed to residential traffic had no higher risk of adverse birth outcomes or pregnancy complications in this study. Future studies may be refined by taking both temporal and spatial variation in air pollution exposure into account.