Different Risk Factors for Very Low Birth Weight, Term-Small-for-Gestational-Age, or Preterm Birth in Japan

Prenatal alcohol exposure and associations with physical size, dysmorphology and neurodevelopment: a systematic review and meta-analysis

BACKGROUND

Fetal alcohol spectrum disorder (FASD) is a significant public health concern, yet there is no internationally agreed set of diagnostic criteria or summary of underlying evidence to inform diagnostic decision-making. This systematic review assesses associations of prenatal alcohol exposure (PAE) and outcomes of diagnostic assessments, providing an evidence base for the improvement of FASD diagnostic criteria.

METHODS

Six databases were searched (inception-February 2023). Case-controls or cohort studies examining associations between participants with/without PAE or a FASD diagnosis and the domains of physical size, dysmorphology, functional neurodevelopment and/or brain structure/neurology were included. Excluded studies were non-empirical, sample size < 10, PAE determined via biological markers only, or no suitable comparison group. Summary data were extracted and associations between outcomes and standardised levels of PAE or FASD diagnosis determined using random-effects meta-analyses. Certainty of the evidence was assessed using GRADE.

RESULTS

Of the 306 included studies, 106 reported physical size, 43 dysmorphology, 195 functional neurodevelopment and 110 structural/neurological outcomes, with 292 different outcomes examined. There was a dose-response relationship between PAE and head circumference, as well as measures of physical size, particularly at birth. There was also an association between higher PAE levels and characteristic sentinel facial dysmorphology, as well as many of the current functional neurodevelopmental outcomes considered during diagnosis. However, data were often lacking across the full range of exposures. There was a lack of evidence from studies examining PAE to support inclusion of non-sentinel dysmorphic features, social cognition, speech-sound impairments, neurological conditions, seizures, sensory processing or structural brain abnormalities (via clinical MRI) in diagnostic criteria. GRADE ratings ranged from very low to moderate certainty of evidence.

CONCLUSIONS

This comprehensive review provides guidance on which components are most useful to consider in the diagnostic criteria for FASD. It also highlights numerous gaps in the available evidence. Future well-designed pregnancy cohort studies should specifically focus on dose-response relationships between PAE and dysmorphology, neurodevelopment and brain structure/neurological outcomes.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO: CRD42021230522.

Maternal birth weight is an indicator of preterm delivery: the Japan environment and children's study

This study aimed to investigate the association between maternal birth weight (MBW) with preterm delivery (PTD) in the Japanese population. To this end, a total of 78,972 Japanese pregnant women were included in a prospective birth cohort study. Multiple logistic regression and multinominal logistic regression models were applied to investigate the associations of MBW with PTD (delivery from 22 to < 37 weeks of gestation), early PTD (delivery from 22 to < 34 weeks), and late PTD (delivery from 34 to < 37 weeks). The results showed that MBW was inversely associated with PTD, early PTD, and late PTD (p-for-trend < 0.0001, 0.0014, and < 0.0001, respectively). The adjusted odds ratios per each 500 g of MBW decrease were 1.167 (95% confidence interval [CI]: 1.118-1.218) for PTD, 1.174 (95% CI: 1.070-1.287) for early PTD and 1.151 (95% CI: 1.098-1.206) for late PTD. The effect size of the association of MBW with early PTD was similar to that with late PTD. This study demonstrated for the first time an association of a low MBW with PTD, early PTD, and late PTD in a Japanese nationwide cohort.

Maternal Age at Menarche Genes Determines Fetal Growth Restriction Risk

We aimed to explore the potential link of maternal age at menarche (mAAM) gene polymorphisms with risk of the fetal growth restriction (FGR). This case (FGR)-control (FGR free) study included 904 women (273 FGR and 631 control) in the third trimester of gestation examined/treated in the Departments of Obstetrics. For single nucleotide polymorphism (SNP) multiplex genotyping, 50 candidate loci of mAAM were chosen. The relationship of mAAM SNPs and FGR was appreciated by regression procedures (logistic/model-based multifactor dimensionality reduction [MB-MDR]) with subsequent in silico assessment of the assumed functionality pithy of FGR-related loci. Three mAAM-appertain loci were FGR-linked to genes such as KISS1 (rs7538038) (effect allele G-odds ratio (OR)allelic = 0.63/pperm = 0.0003; ORadditive = 0.61/pperm = 0.001; ORdominant = 0.56/pperm = 0.001), NKX2-1 (rs999460) (effect allele A-ORallelic = 1.37/pperm = 0.003; ORadditive = 1.45/pperm = 0.002; ORrecessive = 2.41/pperm = 0.0002), GPRC5B (rs12444979) (effect allele T-ORallelic = 1.67/pperm = 0.0003; ORdominant = 1.59/pperm = 0.011; ORadditive = 1.56/pperm = 0.009). The haplotype ACA FSHB gene (rs555621*rs11031010*rs1782507) was FRG-correlated (OR = 0.71/pperm = 0.05). Ten FGR-implicated interworking models were founded for 13 SNPs (pperm ≤ 0.001). The rs999460 NKX2-1 and rs12444979 GPRC5B interplays significantly influenced the FGR risk (these SNPs were present in 50% of models). FGR-related mAAM-appertain 15 polymorphic variants and 350 linked SNPs were functionally momentous in relation to 39 genes participating in the regulation of hormone levels, the ovulation cycle process, male gonad development and vitamin D metabolism. Thus, this study showed, for the first time, that the mAAM-appertain genes determine FGR risk.

Increased incidence of renal and urinary tract anomalies among individuals with fetal alcohol spectrum disorders (FASD)

BACKGROUND

Fetal alcohol spectrum disorders (FASD) in a spectrum of neurodevelopmental conditions resulting from prenatal alcohol exposure (PAE). Animal models have confirmed the toxic effects of PAE on the kidneys and urinary tract, yet the evidence from human studies is contradictory. The purpose of this study was to establish the incidence of renal and urinary tract anomalies (RUTA), impaired kidney function, and hypertension among patients with FASD.

METHODS

Children from the FASD Diagnostic Center with FASD diagnosis (FAS, pFAS, or ARND) were offered participation in the study. The control group consisted of patients from the Gastroenterology Department of the same hospital. The patients underwent renal and urinary tract ultrasound examination. The serum creatinine level was also evaluated and the blood pressure was taken twice. Polish OLAF charts were used to determine the percentiles of blood pressure.

RESULTS

The incidence of kidney and urinary tract defects in the study group was significantly higher than in the control group (OR: 2.64 [1.60-4.34]). The kidney size among FASD patients was significantly lower (73 mm [60-83] vs. 83 mm [70-96]; p < .001) when compared to the control group. No differences were observed in the estimated glomerular filtration rate. In the study group, significantly lower systolic blood, diastolic blood pressure, percentile of systolic pressure, and diastolic pressure were observed.

CONCLUSIONS

RUTA occurred more frequently among patients with FASD compared to the control group, and decreased kidney size was also demonstrated among patients with FASD. However, impaired kidney function and the risk of hypertension were not observed.

Difference in risk of preterm and small-for-gestational-age birth depending on maternal occupations in Japan

OBJECTIVES

In this study, an association between the mother's occupations with preterm and small-for-gestational-age (SGA) births was investigated using national data in Japan, and individual-level birth data from the Report of Vital Statistics: Occupational and Industrial Aspects in the 2015 fiscal year were used. Preterm and SGA birth rates were calculated for each of infant characteristics, and relative risk of each type of maternal occupations (categorized into 12 types) for the outcomes was estimated using a log binomial regression model.

RESULTS

Data of 997,600 singleton births were analyzed. Among maternal occupations, preterm birth rate was highest among carrying, cleaning, packaging, and related workers (5.65%) and lowest among security workers (4.24%). SGA birth rate was highest among manufacturing process workers (5.91%) and lowest among security workers (4.00%). We found significantly elevated risks for preterm birth among manufacturing process workers compared with unemployed mothers, and significantly elevated risks for SGA birth compared with unemployed mothers were observed among sales workers, service workers, and manufacturing process workers. In contrast, security workers had a significantly decreased risk for SGA birth compared with unemployed mothers.

Changes in preterm and extremely preterm birth rates in Japan after the introduction of obstetrical practice guidelines in 2008

AIM

Obstetrical guidelines were established in Japan in 2008, and obstetrical diagnoses and treatments were subsequently standardized nationally. We examined changes in the preterm birth rate (PTBR) and extremely preterm birth rate (EPTBR) following the introduction of such guidelines.

METHODS

Information on 50 706 432 live births in Japan between 1979 and 2021, including Japanese reproductive medicine, the childbearing age of pregnant women, and the employment status of reproductive-age women between 2007 and 2020, were obtained from the Japanese government and academic societies. Regression analysis was used to compare chronological changes nationally and those of eight Japanese regions. Regional and national average PTBRs and EPTBRs from 2007 to 2020 were compared by using a repeated measures analysis of variance.

RESULTS

From 1979 to 2007, PTBRs and EPTBRs in Japan increased significantly. However, from 2008, the national PTBR and EPTBR decreased until 2020 (p < 0.001) and 2019 (p = 0.02), respectively. From 2007 to 2020, overall PTBR and EPTBR were 5.68% and 0.255%, respectively. A significant difference in the PTBR and EPTBR existed between the eight Japanese regions. During this period, the number of pregnancies using assisted reproductive technology increased from 19 595 to 60 381, pregnant women became older, the employment rate of those of reproductive age increased, and nonregular employment was 54%, which was 2.5 times higher than for men.

CONCLUSIONS

In Japan, after obstetrical guidelines were enacted in 2008, PTRBs decreased significantly even under the pressure of increasing preterm births. Countermeasures may be necessary for regions showing high PTBRs.

Association between infant mortality and parental educational level: An analysis of data from Vital Statistics and Census in Japan

This study investigated the association between parental educational level and infant mortality using data from Vital Statistics and Census in Japan. We used the Census data in 2020 and birth and mortality data from the Vital Statistics from 2018 to 2021 in Japan. Data linkage was conducted between birth data and the Census to link the educational level with parents for birth data and between the birth data and mortality data to identify births that resulted in infant mortality. Four educational levels were compared: "junior high school," "high school," "technical school or junior college," and "university." A multivariate logistic regression model was used to investigate an association between parental educational level and infant mortality using other risk factors as covariates. After the data linkage, data on 890,682 births were analyzed. The proportion of junior high school or high school graduates was higher among fathers and mothers for births with infant mortality compared with that among those for births without infant mortality; in contrast, the proportion of university graduates was lower for births with infant mortality than those without infant mortality. Regression analysis showed that mothers with junior high school or high school graduates were significantly and positively associated with infant mortality compared with those with university graduates. As a conclusion, lower educational level in mothers was positively associated with infant mortality, and it was shown that a difference in infant mortality depending on parental educational level existed in Japan.

Associations between intimate partner violence and adverse birth outcomes during pregnancy: a systematic review and meta-analysis

Background

Intimate partner violence (IPV) has been associated with an elevated risk of multiple adverse birth outcomes, yet little is known about how specific IPV influences adverse birth outcomes. The aim of this study was to examine the association between IPV during pregnancy and adverse birth outcomes (i.e., preterm birth, low birth weight, and stillbirth).

Methods

Systematic searches were conducted using four databases: EMBASE, Web of Science, PubMed, and CINAHL for observational studies published from 1 January 2011 to 31 August 2021. Two reviewers independently carried out the literature search, study selection, data extraction, assessment of the study, and risk of bias assessment; disagreements were resolved by a third reviewer. A random-effect model was used to calculate the odds ratio (OR) with a 95% confidence interval (CI) for preterm birth, low birth weight, and stillbirth. I² statistic accompanied by chi-square p-value was used to assess heterogeneity, and funnel plot and Peter's test were used to assess publication bias.

Results

In total, 23 studies met the inclusion criterion. IPV was associated with preterm birth (OR = 1.84; 95% CI: 1.37-2.49; I² = 88%), low birth weight (OR = 2.73; 95% CI: 1.66-4.48; I² = 95%), and stillbirth (OR = 1.74; 95% CI: 0.86-3.54; I² = 64%). We attained comparable results among all specific IPV including physical, sexual, emotional, and mixed.

Conclusion

Intimate partner violence and specific IPV during pregnancy were significantly associated with adverse birth outcomes, especially for physical IPV. An urgent need for greater action to prevent or intervene in IPV during pregnancy is warranted.

Systematic review registration

CRD42021282936, https://www.crd.york.ac.uk/prospero/.

Analysis of an Association between Preterm Birth and Parental Educational Level in Japan Using National Data

Preterm birth rate depending on parental educational level in recent years has not been surveyed in Japan. In this study, we showed the trend in preterm birth rate depending on parental educational level from 2000 to 2020 by linking data from the Census regarding individuals' educational level and parents in birth data of the vital statistics. Four types of parental educational level, namely junior high school, high school, technical school or junior college, and university or graduate school, were compared. Slope and relative indexes of inequality for preterm birth by educational level were computed by binomial models. Data on 3,148,711 births and 381,129,294 people were used in the analysis, and data on 782,536 singleton births were used after data linkage. The preterm birth rate (%) for junior high school graduate mothers and fathers was 5.09 and 5.20 in 2020, respectively. Contrarily, the preterm birth rate (%) for parents who graduated from a university or graduate school was 4.24 for mothers and 4.39 for fathers, and the rate tended to increase as educational level decreased, irrespective of parental gender. Results of inequality indexes showed that a statistically significant inequality by parental educational level persisted from 2000 to 2020.

Detecting geographical clusters of low birth weight and/or preterm birth in Japan

In Japan, mean birth weight has significantly decreased from 3152 g in 1979 to 3018 g in 2010 and the prevalence of preterm birth (PTB) has risen to 5.7% in the last thirty years. However, the presence and magnitude of geographical differences in low birthweight (LBW) and/or PTB in Japan is not well understood. We implemented spatial analysis to identify localized clusters and hot spots of LBW and/or PTB during 2012-2016. The Japan national birth database was used in this study. A total of 5,041,685 (male: 2,587,415, female: 2,454,270) births were used for spatial analysis using empirical Bayes estimates of the incidence rate of LBW and/or PTB and spatial scan tests to detect hot-spot areas with p values calculated from Monte Carlo iterations. The most and second likely clusters were located in two areas: (1) the small islands in south-west Japan (Amami and Okinawa, Relative risk = 1.09-1.67 with p < 0.001) and (2) the cities on the base of Mt. Fuji, stretching over three neighboring prefectures of Yamanashi, Shizuoka and Kanagawa (Relative risk = 1.10-1.55 with p < 0.001), respectively. We need to optimize the medical resource allocations based on the evidence in geographical clustering of LBW and/or PTB at specific locations in Japan.

Maternal and Placental Risk Factors for Small Gestational Age and Fetal Malnutrition

AIMS

This case-control study was conducted to identify maternal and placental risk factors of small-for-gestational-age (SGA) and fetal malnutrition.

METHODS

Cases comprised 104 consecutively delivered SGA neonates (determined as per INTERGROWTH- 21st standard). An equal number of next-born gestation and gender-matched appropriatefor- gestational age (AGA) neonates served as controls. Maternal risk factors were enquired, and placentae were evaluated by clinical and histopathological examination. Nutrition of the neonates was assessed by the clinical assessment of nutrition (CAN) score. Univariate and multivariate logistic regression analysis was done to identify the maternal and placental risk factors.

RESULTS

The prevalence of SGA in the present study was 23.9%. Maternal fever [adjusted Odds Ratio (aOR), 95% confidence interval (CI), 16.3 (3.5-124.1); p = 0.001], presence of placental syncytial knots [aOR (95% CI), 2.9 (1.1-9.1); p = 0.04] and placental calcifications [aOR (95% CI), 3(1.1- 8.7); p = 0.03], were identified as independent predictors of SGA using multivariate logistic regression analysis. Malnutrition (SCORE <25) affected 64% of SGA and 16.3% of AGA neonates. The only risk factor significantly associated with malnourished SGA was prematurity, whereas malnourished AGA was significantly associated with prematurity and fetal distress. In-hospital morbidities significantly higher in SGA were perinatal asphyxia, respiratory distress, need for respiratory support, polycythemia, hypoglycemia, and feeding intolerance. Mortality before discharge was 4.8% and 3.8% in SGA and AGA population, respectively (p > 0.05). Neonatal outcomes were comparable among well-nourished, malnourished SGA and AGA groups.

CONCLUSION

Maternal fever, placental syncytial knots, and calcifications were independent risk factors of SGA, whereas prematurity and fetal distress were responsible for malnutrition.

Paternal Nicotine/Ethanol/Caffeine Mixed Exposure Induces Offspring Rat Dysplasia and Its Potential "GC-IGF1" Programming Mechanism

Clinical and animal studies suggest that paternal exposure to adverse environments (bad living habits and chronic stress, etc.) has profound impacts on offspring development; however, the mechanism of paternal disease has not been clarified. In this study, a meta-analysis was first performed to suggest that paternal exposure to nicotine, ethanol, or caffeine is a high-risk factor for adverse pregnancy outcomes. Next, we created a rat model of paternal nicotine/ethanol/caffeine mixed exposure (PME), whereby male Wistar rats were exposed to nicotine (0.1 mg/kg/d), ethanol (0.5 g/kg/d), and caffeine (7.5 mg/kg/d) for 8 weeks continuously, then mated with normal female rats to obtain a fetus (n = 12 for control group, n = 10 for PME group). Then, we analyzed the changes in paternal hypothalamic-pituitary-adrenal (HPA) axis activity, testicular function, pregnancy outcomes, fetal serum metabolic indicators, and multiple organ functions to explore the mechanism from the perspective of chronic stress. Our results demonstrated that PME led to enhanced paternal HPA axis activity, decreased sperm quality, and adverse pregnancy outcomes (stillbirth and absorption, decreased fetal weight and body length, and intrauterine growth retardation), abnormal fetal serum metabolic indicators (corticosterone, glucolipid metabolism, and sex hormones), and fetal multi-organ dysfunction (including hippocampus, adrenal, liver, ossification, and gonads). Furthermore, correlation analysis showed that the increased paternal corticosterone level was closely related to decreased sperm quality, adverse pregnancy outcomes, and abnormal offspring multi-organ function development. Among them, the decreased activity of the glucocorticoid-insulin-like growth factor 1 (GC-IGF1) axis may be the main mechanism of offspring development and multi-organ dysfunction caused by PME. This study explored the impact of common paternal lifestyle in daily life on offspring development, and proposed the GC-IGF1 programming mechanisms of paternal chronic stress-induced offspring dysplasia, which provides a novel insight for exploring the important role of paternal chronic stress in offspring development and guiding a healthy lifestyle for men.

Processed Dietary Patterns during Pregnancy Are Associated with Low Birth Weight at Term among Women of Advanced and Non-Advanced Age

Inappropriate dietary intake during pregnancy is a key factor in low birth weight (LBW). This study compares LBW between healthy and processed dietary patterns by focusing on women of advanced maternal age. A cross-sectional survey was conducted with 327 postpartum women in Taiwan. The participants were assigned to two groups according to their age (≥35 years, n = 151; and 20−34 years, n = 176). An online questionnaire asked women how often they consumed 27 food items during their pregnancy. The prevalence of LBW was higher in the processed dietary pattern (79.3%) than in the healthy pattern (13.78%, p < 0.001). LBW was positively correlated with advanced maternal age (≥35 ages), low pre-pregnancy weight (BMI less than 18.5 kg/m2), insufficient gestational weight gain (GWG), and processed dietary patterns. Older mothers were 5.8 times more likely to have infants with LBW (odds ratio = 5.8; 95% confidence interval 2.0−16.6). A processed dietary pattern was 9.4 times more likely to result in LBW. Insufficient GWG was significantly positively associated with LBW (OR = 4.0; 95%CI 1.4−11.6). Maternal diet during pregnancy is an important modifiable factor for LBW. Prenatal advice should emphasize optimal nutrition, especially in older and underweight women.

Prenatal alcohol exposure and adverse fetal growth restriction: findings from the Japan Environment and Children's Study

BACKGROUNDS

Japanese studies on the association between maternal alcohol consumption and fetal growth are few. This study assessed the effect of maternal alcohol consumption on fetal growth.

METHODS

This prospective birth cohort included 95,761 participants enrolled between January 2011 and March 2014 in the Japan Environment and Children's Study. Adjusted multiple linear and logistic regression models were used to assess the association between prenatal alcohol consumption and infant birth size.

RESULTS

Consumption of a weekly dose of alcohol in the second/third trimester showed a significant negative correlation with standard deviation (SD; Z) scores for body weight, body length, and head circumference at birth, respectively. Consumption of a weekly dose of alcohol during the second/third trimester had a significant positive correlation with incidences of Z-score ≤ -1.5 for birth head circumference. Associations between alcohol consumption in the second/third trimester and Z-score ≤ -1.5 for birth weight or birth length were not significant. Maternal alcohol consumption in the second/third trimester above 5, 20, and 100 g/week affected body weight, body length, and head circumference at birth, respectively.

CONCLUSION

Low-to-moderate alcohol consumption during pregnancy might affect fetal growth. Public health policies for pregnant women are needed to stop alcohol consumption during pregnancy.

IMPACT

This study examined the association between maternal alcohol consumption and fetal growth restriction in 95,761 pregnant Japanese women using the prospective birth cohort. Maternal alcohol consumption in the second/third trimester more than 5, 20, and 100 g/week might affect fetal growth in body weight, body length, and head circumference, respectively. The findings are relevant and important for educating pregnant women on the adverse health effects that prenatal alcohol consumptions have on infants.

Association between Maternal Factors, Preterm Birth, and Low Birth Weight of Chilean Singletons

There has been an increase in preterm (PT) births in Western countries in recent years, which is associated with low-birthweight (LBW) children. The aim of this study was to determine the association between maternal factors and PT and LBW Chilean newborns. Methods: This was an analytical cross-sectional study of a national sample of 903,847 newborns and their mothers. The newborn gestational age, birth weight, maternal age, marital status, education, employment situation, and residence were analyzed. A multivariate logistic regression model was applied (α = 0.05) (STATA v.15). The prevalence was 6.8% and 5.0% for PT and LBW, respectively. The probability of the newborns being PT and LBW was 1.18 and 1.22 times if their mothers had <12 years of education and 1.38 and 1.29 times if the mothers were ≥35 years old, respectively. Mothers with <12 years education and ≥35 years were risk factors for PT and LBW newborns. Maternal educational attainment was a protective factor for the Chilean newborns, and a maternal age ≥35 years was a risk factor for PT and LBW.

Risk factors associated with low birth weight

OBJECTIVES

Low birth weight (LBW) is one of the major factors affecting child morbidity and mortality worldwide. Every day, approximately 800 women die from causes related to pregnancy and childbirth worldwide. Maternal ill health increases the risk of LBW. This study seeks to investigate determinants and incidence of LBW.

METHODS

This study was conducted based on the medical records of mothers and their 1,946 infants born in 2016-2019 at the Department of Gynaecology and Obstetrics of Louis Pasteur University Hospital in Košice. Data on mothers and newborn infants were obtained from the Reports on mothers at childbirth. The inclusion criteria were singleton births and birth weight > 500 g. The exclusion criteria were twins or multiple births, congenital anomalies and stillbirths, birth weight ≥ 4,000 g or ≤ 500 g, and Roma ethnicity. Roma children are more likely to be born prematurely, with low birth weight. Roma mothers have different lifestyle. Univariate analysis was employed to evaluate the association between the independent variables and LBW. Variables that were found to be statistically significant were then further analysed using multivariable logistic analysis for each dependent variable. The implementation of the research was approved by the Ethics Committee.

RESULTS

Of 1,946 newborns, 271 (13.90%) have low birth weight. The mean of birth weight at delivery was 3,068.62 (SD 671.16) grams. Factors that were associated with LBW were primary maternal education (OR = 2.98, 95% CI: 1.08-8.21, p = 0.034), marital status single (OR = 2.88, 95% CI: 1.68-4.94, p < 0.001), number of prenatal care visits less than 8 (OR = 1.62, 95% CI: 1.01-2.61, p = 0.047), and preterm birth (OR = 74.94, 95% CI: 45.44-123.61, p < 0.001).

CONCLUSION

The reducing of LBW requires strategies to improve maternal lifestyle, maternal care before, during and after birth and to strengthen social support.

Risk scores for predicting small for gestational age infants in Japan: The TMM birthree cohort study

This study aimed to construct a prediction model for small-for-gestational-age (SGA) infants in Japan by creating a risk score during pregnancy. A total of 17,073 subjects were included in the Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study, a prospective cohort study. A multiple logistic regression model was used to construct risk scores during early and mid-gestational periods (11–17 and 18–21 weeks of gestation, respectively). The risk score during early gestation comprised the maternal age, height, body mass index (BMI) during early gestation, parity, assisted reproductive technology (ART) with frozen-thawed embryo transfer (FET), smoking status, blood pressure (BP) during early gestation, and maternal birth weight. The risk score during mid-gestation also consisted of the maternal age, height, BMI during mid-gestation, weight gain, parity, ART with FET, smoking status, BP level during mid-gestation, maternal birth weight, and estimated fetal weight during mid-gestation. The C-statistics of the risk scores during early- and mid-gestation were 0.658 (95% confidence interval [CI]: 0.642–0.675) and 0.725 (95% CI: 0.710–0.740), respectively. In conclusion, the predictive ability of the risk scores during mid-gestation for SGA infants was acceptable and better than that of the risk score during early gestation.

A method for identifying critical time windows of maternal air pollution exposures associated with low birth weight in offspring using massive geographic data

Associations between maternal exposures to air pollutants and low birth weight (LBW) in offspring varied when different exposure windows were considered. Methods used in previous studies lacked flexibility in delineating exposure windows and did not consider time periods before conception, which may restrict the discoveries of critical exposure windows. This study introduces a novel method to identify critical windows of maternal air pollution exposures associated with LBW in offspring using massive georeferenced data. Through a case-control study based on birth data (94,106 LBW cases and 376,424 controls) and air quality monitoring data (367 chemicals) in Texas during 1996-2008, this study used the average ambient concentration measured by the monitoring site closest to the residence location of a mother during a time window as the maternal exposure to a specific chemical during that exposure window. Binary logistic regression was utilized to estimate air pollutant-LBW associations in different exposure windows. The odds ratios (ORs) were adjusted for child's sex, gestational weeks, maternal age, race/ethnicity, and education. The adjusted ORs were plotted against the exposure window series of different sizes for each chemical, aiming at interactively visualizing and exploring the critical exposure windows across multiple temporal scales. This study identifies ten chemicals and seventeen corresponding critical exposure windows where strong air pollutant-LBW associations are detected. The ten identified chemicals are benzaldehyde, sum of Photochemical Assessment Monitoring Stations (PAMS) target compounds, n-undecane, m-tolualdehyde, organic carbon fraction 2 (OC2), ethylene dibromide, valeraldehyde, propionaldehyde, 4-methyl-1-pentene, and zirconium. Nine critical exposure windows involving six chemicals start more than five months prior to conception, seven windows involving five chemicals commence in the second and/or third trimester of pregnancy, and the remaining one window is located in other time periods. The novel method reveals a number of critical time windows of maternal exposure to ten chemicals that are positively associated with LBW in offspring. These ten chemicals were identified as LBW risk factors for the first time. Additional studies with more data are needed to validate the results in the future.

Association between subjective degree of influence in class and thinness among adolescents in Japan

Social status in school, measured by subjective degree of influence in class (DOI), may influence thinness among adolescents. This study examined the association between subjective degree of influence in class and thinness among Japanese adolescents. Data were obtained from the Kochi Child Health Impact of Living Difficulty (K-CHILD) study in 2016, which Was a population-based study targeting 5th, 8th and 11th grade adolescents living in Kochi Prefecture, Japan (N = 9,998). DOI was assessed by adolescents via questionnaire. Weight and height were given by caregivers for 5th grade adolescents, whilst they were self-reported for 8th and 11th grade adolescents. Collected data on weight and height were used to calculate body mass index z-scores of WHO standards. Models included grade, gender, number of friends, household income, location of school and depressive symptoms as covariates. The results showed that both high and low DOI were positively associated with thinness after adjustment for other individual covariates (high DOI, OR = 1.59, 95% CI 1.05-2.43; low DOI, OR = 2.04, 95% CI 1.36-3.06). Further stratification by gender revealed that low DOI was positively associated with thinness (OR = 2.14, 95% CI 1.34-3.44) among boys, but there was no association among girls. Both high and low DOI were associated with the risk of being thin in adolescents. Focusing on DOI for adolescents may be important to address thinness among adolescents. Further studies are needed to examine the causality between DOI and thinness in adolescents.

Evidence of changes in the oral language in children born full-term and small for gestational age: a systematic review

Abstract Objective: To perform a systematic review in order to verify the association between full-term birth of small for gestational age (SGA) children and the outcomes in the development of oral language. Data source: Articles from MEDLINE/PubMed, Web of Science, Embase, Lilacs, SciELO and Cochrane Library databases were identified, selected and critically evaluated by two independent reviewers and a judge, blindly, without language restriction and publication period. The PRISMA tool was used, and original studies with a theme involving children born full-term and SGA were included, outcome related to aspects of oral language development, as well as the use of tests, scales and/or specific questionnaires for the investigation, whose methodology was described in full, with children as the target population. Data synthesis: The researchers included nine articles based on the eligibility criteria. Studies have shown that being born SGA can interfere in aspects related to language and reported greater chances of under performance in SGA children when compared to children with appropriate size for gestational age. It was observed that the different studies did not have a uniform design, and the objectives were quite diverse. Furthermore, few of them had as focus issues related to the assessment of language, as well as the variability of instruments used to investigate this domain. Conclusions: The effects of low weight for gestation age in full-term infants continue beyond the neonatal period and may impact on children’s performance, mainly with regard to oral language development.

Evidências de alterações na linguagem oral de crianças nascidas a termo pequenas para a idade gestacional: uma revisão sistemática

Resumo Objetivo: Realizar uma revisão sistemática para verificar a associação entre o nascimento a termo de crianças pequenas para a idade gestacional (PIG) e os desfechos no desenvolvimento da linguagem oral. Fontes de dados: Artigos dos bancos de dados MEDLINE/PubMed, Web of Science, Embase, LILACS, SciELO e Cochrane Library foram identificados, selecionados e avaliados criticamente por dois revisores independentes e um juiz, às cegas, sem restrições de idioma e período de publicação. A ferramenta PRISMA foi utilizada e foram incluídos estudos originais envolvendo crianças nascidas a termo e PIG, desfechos relacionados a aspectos do desenvolvimento da linguagem oral, bem como o uso de testes, escalas e/ou questionários específicos para a investigação, cuja metodologia estava descrita na íntegra, com crianças como população-alvo. Síntese dos dados: Nove artigos foram incluídos a partir dos critérios de elegibilidade. Os estudos demonstraram que nascer PIG pode interferir em aspectos relacionados à linguagem e relataram que as chances de crianças PIG apresentarem um desempenho inferior são maiores quando comparadas as com tamanho adequado para a idade gestacional. Observou-se que os diferentes estudos não tinham um delineamento uniforme e seus objetivos eram bastante diversificados. Além disso, poucos focavam em questões relacionadas à avaliação da linguagem e foi possível notar uma variabilidade de instrumentos utilizados para investigar esse domínio. Conclusões: Os efeitos do baixo peso ao nascer em nascidos a termo persistem além do período neonatal e podem ter impacto no desempenho infantil, principalmente no que se refere ao desenvolvimento da linguagem oral.

An Association between Maternal Occupations and Low Birth Weight Infants in Japan from 1995 to 2015

Differences in low birth weight rate depending on maternal socioeconomic characteristics have not yet been demonstrated using the Vital Statistics in Japan; therefore, this study aimed to investigate these differences according to maternal occupations. “Report of Vital Statistics: Occupational and Industrial Aspects” and the Vital Statistics in Japan were used every five years from 1995 to 2015. Nine types of occupations were compared. The low birth weight rate was calculated according to maternal occupations and year. Also, the standardized low birth weight ratio was obtained by dividing the number of low-birth-weight infants for each maternal occupation by an expected number of low birth weight infants. The standardized low birth weight ratio for manual workers was the highest among all occupations from 2000 to 2015, and it was significantly higher than one throughout the years. The ratio for clerical workers was also significantly higher than one from 1995 to 2010. Whereas, the ratio for farmers was significantly lower than one in most of the years. It was suggested that health guidance and prenatal care are particularly needed for manual workers, and a study investigating the differences in prenatal characteristics among maternal occupations is necessary for finding a reason for disparity.

Hokkaido birth cohort study on environment and children's health: cohort profile 2021

BACKGROUND

The Hokkaido Study on Environment and Children's Health is an ongoing study consisting of two birth cohorts of different population sizes: the Sapporo cohort and the Hokkaido cohort. Our primary objectives are to (1) examine the effects that low-level environmental chemical exposures have on birth outcomes, including birth defects and growth retardation; (2) follow the development of allergies, infectious diseases, and neurobehavioral developmental disorders, as well as perform a longitudinal observation of child development; (3) identify high-risk groups based on genetic susceptibility to environmental chemicals; and (4) identify the additive effects of various chemicals, including tobacco.

METHODS

The purpose of this report is to provide an update on the progress of the Hokkaido Study, summarize recent results, and suggest future directions. In particular, this report provides the latest details from questionnaire surveys, face-to-face examinations, and a collection of biological specimens from children and measurements of their chemical exposures.

RESULTS

The latest findings indicate different risk factors of parental characteristics on birth outcomes and the mediating effect between socioeconomic status and children that are small for the gestational age. Maternal serum folate was not associated with birth defects. Prenatal chemical exposure and smoking were associated with birth size and growth, as well as cord blood biomarkers, such as adiponectin, leptin, thyroid, and reproductive hormones. We also found significant associations between the chemical levels and neuro development, asthma, and allergies.

CONCLUSIONS

Chemical exposure to children can occur both before and after birth. Longer follow-up for children is crucial in birth cohort studies to reinforce the Developmental Origins of Health and Disease hypothesis. In contrast, considering shifts in the exposure levels due to regulation is also essential, which may also change the association to health outcomes. This study found that individual susceptibility to adverse health effects depends on the genotype. Epigenome modification of DNA methylation was also discovered, indicating the necessity of examining molecular biology perspectives. International collaborations can add a new dimension to the current knowledge and provide novel discoveries in the future.

Extremely and Very Preterm Deliveries in a Maternity Unit of Inappropriate Level: Analysis of Socio-Residential Factors

PURPOSE

To analyze the socio-residential factors associated with extremely and very preterm deliveries occurring in non-level 3 maternity units in France.

MATERIALS AND METHODS

This is a population-based observational retrospective study using national hospital data from 2012 to 2014. A generalized estimating equations regression model was used to study the characteristics of women who delivered very preterm and the socio-residential risk factors for not delivering in a level 3 maternity unit at 24-31+6d weeks of gestation.

RESULTS

Among deliveries resulting in live births and without contraindication to in-utero transfer, we identified 9198 extremely or very preterm deliveries; 2122 (23.1%) of these were managed in a non-level 3 unit. Our study showed that young maternal age (women under 20 years at delivery) was associated with the risk of giving birth prematurely in a non-level 3 maternity, and particularly in a level 1 maternity unit (adjusted relative risk, 1.53; 95% CI 1.09-2.16). Living more than 30 minutes away from the closest level 3 unit increased the risk of delivering very preterm in a level 1 or 2 unit. Living in an urban area or urban periphery increased the risk of giving birth in a level 2 maternity unit (adjusted relative risk, 1.53; 95% CI 1.28-1.83 and 1.42; 95% CI 1.17-1.71, respectively).

CONCLUSION

This study shows that young pregnant women living more than 30 minutes from a level 3 hospital have an increased risk of delivering in a maternity unit that is not equipped to deal with premature births. The risk also increases with an urban place of residence when the delivery occurs in a level 2 unit. A clearer understanding of the population at risk of delivering prematurely in a non-level 3 maternity could lead to improvements in structuring healthcare to encourage earlier management and better support.

Hypertensive Disorders during Pregnancy (HDP), Maternal Characteristics, and Birth Outcomes among Japanese Women: A Hokkaido Study

Hypertension during pregnancy causes a greater risk of adverse birth outcomes worldwide; however, formal evidence of hypertensive disorders during pregnancy (HDP) in Japan is limited. We aimed to understand the association between maternal characteristics, HDP, and birth outcomes. In total, 18,833 mother-infant pairs were enrolled in the Hokkaido study on environment and children’s health, Japan, from 2002 to 2013. Medical records were used to identify hypertensive disorders and birth outcomes, namely, small for gestational age (SGA), SGA at full term (term-SGA), preterm birth (PTB), and low birth weight (LBW). The prevalence of HDP was 1.9%. Similarly, the prevalence of SGA, term-SGA, PTB, and LBW were 7.1%, 6.3%, 7.4%, and 10.3%, respectively. The mothers with HDP had increased odds of giving birth to babies with SGA (2.13; 95% Confidence Interval (CI): 1.57, 2.88), PTB (3.48; 95%CI: 2.68, 4.50), LBW (3.57; 95%CI: 2.83, 4.51) than normotensive pregnancy. Elderly pregnancy, low and high body mass index, active and passive smoking exposure, and alcohol consumption were risk factors for different birth outcomes. Therefore, it is crucial for women of reproductive age and their families to be made aware of these risk factors through physician visits, health education, and various community-based health interventions.

Anything New about Paternal Contribution to Reproductive Outcomes? A Review of the Evidence

Paternal health and behavioral lifestyles affect reproductive and neonatal outcomes and yet the magnitude of these effects remain underestimated. Even though these impacts have been formally recognized as a central aspect of reproductive health, health care services in Europe often neglect the involvement of fathers in their reproductive programs. Following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines for systematic reviews, a literature search was carried out to assess the possible impact of paternal health on reproductive outcomes. The comprehensive strategy included cohort studies and meta-analysis available on PubMed, Web of Science, CINAHL, and Google scholar. Cross-referencing of bibliographies of the selected papers ensured wider study capture. Paternal factors were grouped into two categories respectively identified with the terms "Biological Paternal Factors" and "Lifestyle Paternal Factors". Advanced age may impair male fertility and affect early pregnancy stages. Increased body mass index, smoking, alcohol and recreational drugs, all alter seminal fluid parameters. Hazardous alcohol use correlates with low birthweight in pregnancy and harmful behavioral lifestyles have been linked to congenital heart defects, metabolic and neurodevelopmental disorders in the offspring. Measures targeting paternal health and lifestyle within the first 1,000 days' timeframe need to be implemented in couples undergoing reproductive decisions. Health professionals, as well as future fathers, must be aware of the benefits for the offspring associated with correct paternal behaviors. More research is needed to build guidelines and to implement specific programs aiming at reproductive health promotion.

Mediating Factors Between Parental Socioeconomic Status and Small for Gestational Age in Infants: Results from the Hokkaido Study on Environment and Children's Health

OBJECTIVES

Previous studies indicated a significant association between small for gestational age (SGA) in infants and their parents' socioeconomic status (SES). Thus, this study aimed to examine if parental factors, such as maternal smoking, and the pre-pregnancy body mass index (BMI) could mediate the associations between parental SES and SGA.

METHODS

The participants of this study were pregnant women who enrolled in an ongoing birth cohort study, the Hokkaido study, during the first trimester of their pregnancies. A total of 14,593 live singleton births were included in the statistical analysis, of which 1011 (6.9%) were SGA. Two structural equation models were employed to evaluate the associations between parental SES, parental characteristics, and SGA.

RESULTS

The effect of low SES on SGA was directly mediated by maternal pre-pregnancy BMI, smoking during the third trimester, and alcohol consumption during the first trimester in the first model, which was based the assumption of independent associations between mediating factors. In the second model, which additionally considered the mediating factors from the first model, smoking during pregnancy mediated decline in parental SES, consequently increased SGA. Moreover, an increase in pregnancy smoking status increased the prevalence of lower maternal pre-pregnancy BMI and its effect on SGA.

CONCLUSIONS FOR PRACTICE

In this study, we observed the independent mediating effect of maternal pre-pregnancy BMI, smoking, and alcohol consumption during pregnancy on low SES and, consequently, SGA, with the additional mediating pathway of SES to smoking to low BMI on SGA.

Novel sex-specific influence of parental factors on small-for-gestational-age newborns

Since fetal programming is sex-specific, there may also be sex-specific in parental influences on newborn birth weight. We aimed to investigate the influence of parental factors on small-for-gestational-age (SGA) infants of different sexes. Based on a pre-pregnancy cohort, multivariate logistic regression was used. 2275 couples were included for analysis. Significant associations were observed among paternal height, pre-pregnancy body mass index (BMI), and SGA in male infants; among maternal height, pre-pregnancy BMI, and SGA in female infants, and among other maternal factors and SGA in both male and female infants. Such sex specificity may be related to genetic, epigenetic, or hormonal influences between parents and infants. In conclusion, there is a sex specificity in the effect of parental height and pre-pregnancy BMI on SGA. The data suggest that future studies on infants should consider the sex-specific differences between the effects of genetic or environmental factors and infants.

Determinants of low birth weight among live birth newborns delivered at public hospitals in Gamo Gofa Zone, South Ethiopia: Unmatched case control study

Background:

Birth weight is one of the major determinants of perinatal survival, infant morbidity, and mortality. There are only few published reports on assessment of low birth weight in Ethiopia and the determinants of low birth weight have not been well characterized.

Objective:

The aim of this study was to assess determinants of low birth weight among live birth newborns delivered at public hospitals in Gamo Gofa Zone, South Ethiopia.

Methods:

Institution-based case control study was conducted from February 25 to April 25, 2018 and consecutively selected 60 cases and 240 controls were enrolled in this study. The data were collected using face-to-face interview and review of medical records. Moreover, we have measured the newborns’ birth weight using a standard weight scale and mother’s mid-upper arm circumference using a standard World Health Organization mid-upper arm circumference measuring tape. Statistical analysis of the data was done using SPSS version 21.

Results:

A total of 300 newborns were included in the study. Late antenatal care booking (adjusted odds ratio = 1.87, confidence interval = [1.32–2.6]), birth interval <2 years (adjusted odds ratio = 0.385, confidence interval = [0.176–0.83]), anemia (adjusted odds ratio = 4.4, confidence interval = [1.84–10.5]), mid-upper arm circumference <23 cm (adjusted odds ratio = 7.99, confidence interval = [3.5–20.3]), nutritional counseling (adjusted odds ratio = 5.85, confidence interval = [2.14–14.8]), and husband smoking (adjusted odds ratio = 4.73; confidence interval = [1.42–15.7]) were found to be determinant factors of low birth weight.

Conclusion:

Most of the determining factors of low birth weight were preventable. Therefore, clinical and public health interventions should target on those determinant factors to prevent its adverse effects.

Continuous association of total bile acid levels with the risk of small for gestational age infants

The association between maternal serum total bile acid (TBA) levels and small-for-gestational-age (SGA) infants is unclear. We investigated the association between various degrees of serum TBA levels and the risk of SGA infants in a Chinese population. The current study performed a cohort study among 11811 mothers with singleton pregnancy. Subjects were divided into seven categories according to maternal serum TBA levels. Interestingly, birth sizes were reduced, whereas the rate of SGA infants was increased across increasing categories of serum TBA. Compared to category 1, adjusted ORs (95%CI) for SGA infants were 0.99 (0.82-1.21) in category 2, 1.22 (0.97-1.53) in category 3, 1.99 (1.53-2.58) in category 4, 2.91 (2.16-3.93) in category 5, 4.29 (3.33-5.54) in category 6, and 9.01 (5.99-13.53) in category 7, respectively. Furthermore, adjusted ORs (95%CI) for SGA infants for each 1-SD increase in serum TBA levels were 1.36 (1.29-1.43) among all subjects, 2.40 (1.82-3.45) among subjects without cholestasis, and 1.13 (1.06-1.22) among subjects with cholestasis, respectively. These results suggest that gestational cholestasis increases the risk of SGA infants. Additionally, our results indicate strong, continuous associations of serum TBA levels below those diagnostic of cholestasis with a decreased birth sizes and an increased risk of SGA infants.

Factors Associated with Preterm Birth and Low Birth Weight in Abu Dhabi, the United Arab Emirates

Both preterm birth and low birth weight (LBW) represent major public health problems worldwide due to their association with the catastrophic effects of morbidity and mortality. Few data exist about such adverse pregnancy outcomes. The current study aimed to investigate the prevalence of and factors associated with preterm birth and LBW among mothers of children under two years in Abu Dhabi, United Arab Emirates. Data were collected in clinical and non-clinical settings across various geographical areas in Abu Dhabi. The data were analyzed using both descriptive and inferential statistics. A total of 1610 mother–child pairs were included in the current study. Preterm birth rate was 102 (6.3%) with a 95% confidence interval [CI] (6.1%, 6.5%) and the LBW rate was 151 (9.4%) with a 95% CI (9.3%, 9.5%). The mean (SD) of gestational age (GA) and birth weight at delivery was 39.1 (1.9) weeks and 3080.3 (518.6) grams, respectively. Factors that were positively associated with preterm birth were Arab mothers, maternal education level below secondary, caesarean section, and LBW. LBW was associated with female children, caesarean section (CS), first child order, and preterm birth. The current study highlighted the need for further interventional research to tackle these public health issues such as reducing the high CS rate and improving maternal education.

Adverse birth outcomes in Guangdong province, China, 2014-2017: a spatiotemporal analysis of 2.9 million births

OBJECTIVES

Adverse birth outcomes pose a great threat to the public health and bring a heavy burden of disease in China. A comprehensive examination of the temporal and spatial trends of preterm birth (PTB), low birth weight (LBW) and small for gestational age (SGA) epidemics can provide some elementary information for subsequent aetiological and epidemiological studies. This study aimed to characterise the spatiotemporal features of PTB, LBW and SGA based on a large cohort of live births in China.

DESIGN

Spatiotemporal descriptive analysis was performed in Guangdong province, China, from 2014 to 2017.

SETTING

Data involving 2 917 098 live births in Guangdong province, China from 2014 to 2017 was collected from Guangdong Birth Certificate System. Information was collected, including the date of birth, gestational age in week, birth weight, sex of the infant, age of the mother and registered residence of the mother.

RESULTS

The estimated rate of PTB, LBW and SGA was 4.16%, 4.14% and 12.86%, respectively. For temporal trends, the rates of PTB, LBW and SGA showed seasonal fluctuations, especially for LBW and SGA. In addition, there were regional differences in the rates of PTB, LBW and SGA between the Pearl River Delta and Non-Pearl River Delta regions. From 2014 to 2017, the high rates of PTB and LBW expanded from the Pearl River Delta region to the Non-Pearl River Delta regions. However, compared with the Pearl River Delta region, the rate of SGA was higher in the Non-Pearl River Delta regions on the whole.

CONCLUSION

The findings of this study contribute to the understanding of the aetiology and epidemiology of PTB, LBW and SGA in south China.

A propensity-matched study of the association between pre-pregnancy maternal underweight and perinatal outcomes of singletons conceived through assisted reproductive technology

RESEARCH QUESTION

Is pre-pregnancy maternal underweight associated with perinatal outcomes of singletons who were conceived through assisted reproductive technology (ART)?

DESIGN

A 10-year (2006-2015) Chinese sample of 6538 women and their singleton infants who were conceived through ART was used to examine the association between pre-pregnancy maternal underweight and perinatal outcomes. Propensity scores for underweight were calculated for each participant using multivariable logistic regression, which was used to match 740 (91.36% of 810) underweight women with 740 normal weight women; the effects of underweight on birth weight and gestational age were then assessed by generalized estimating equation model.

RESULTS

After propensity score matching, the birth weight was lower (difference -136.83 g, 95% CI -184.11 to -89.55 g) in the underweight group than in the normal weight group. The risks of low birth weight (LBW) and small for gestational age (SGA) were increased in the underweight group compared with those in the normal weight group (LBW: RR 1.64, 95% CI 1.01 to 2.67; SGA: RR 1.46, 95% CI 1.06 to 2.02). The risks of fetal macrosomia and being large for gestational age (LGA) were decreased in the underweight group compared with those in the normal weight group (macrosomia: RR 0.39, 95% CI 0.26 to 0.61; LGA: RR 0.36, 95% CI 0.24 to 0.53). The associations between underweight, gestational age and preterm birth were not statistically significant.

CONCLUSIONS

Among women undergoing ART, pre-pregnancy maternal underweight was associated with lower birth weight, increased LBW and SGA risks, and decreased fetal macrosomia and LGA risks in singleton infants.

[Importance of Two Birth Cohorts (n=20,926 and n=514): 15 Years' Experience of the Hokkaido Study on Environment and Children's Health: Malformation, Development and Allergy]

Since "Our Stolen Future" by Theo Colborn was published in 1996, global interest on the impact of chemical substances, such as the endocrine-disrupting action of chemicals, has increased. In Japan, "The Hokkaido Study on Environment and Children's Health: Malformation, Development and Allergy" was launched in 2001. It was a model of Japan Environment and Children's Study of the Ministry of the Environment. In a large-scale, Hokkaido cohort, we obtained the consent of 20,926 mothers at the organogenesis stage with the cooperation of 37 obstetrics clinics in Hokkaido. We tracked the effects of endocrine disruptors on developmental disorders. In a small-scale Sapporo cohort, we observed in detail the neuropsychiatric development of children with the consent of 514 mothers in their late pregnancy. We examined how prenatal exposure to low concentrations of environmental chemicals affect the development of organs and the postnatal development of children. Maternal exposure to POPs, such as PCB/dioxins and perfluorinated alkyl substances, has affected not only children's birth size, thyroid functions, and sex hormone levels, but also postnatal neurodevelopment, infection, and allergy among others. The associations of short-half-life substances, such as DEHP and BPA, with obesity, ASD, and ADHD have been investigated. Gene-environment interactions have been found for smoking, caffeine, folic acid, and PCB/dioxin. In 2015, our center was officially designated as the WHO Collaborating Centre for Environmental Health and Prevention of Chemical Hazards, and we continue to the contribute to the global perspectives of child health.