Association between maternal characteristics and neonatal birth weight in a Korean population living in the Seoul metropolitan area, Korea: a birth cohort study (COCOA)

Association of ambient air pollution with depressive and anxiety symptoms in pregnant women: A prospective cohort study

BACKGROUND

Air pollution is associated with depressive and anxiety symptoms in the general population. However, this relationship among pregnant women remains largely unknown.

OBJECTIVE

To evaluate the association between pregnancy air pollution exposure and maternal depressive and anxiety symptoms during the third trimester assessed using the Center for Epidemiologic Studies-Depression and State-Trait Anxiety Inventory scales, respectively.

METHODS

We analyzed 1481 pregnant women from a cohort study in Seoul. Maternal exposure to particulate matter with an aerodynamic diameter <2.5 μm (PM_2.5) and <10 μm (PM₁₀), as well as to nitrogen dioxide (NO₂) and ozone (O₃) for each trimester and the entire pregnancy was assessed at participant's residential address by land use regression models. We estimated the relative risk (RR) and corresponding confidence interval (CI) of the depressive and anxiety symptoms associated with an interquartile range (IQR) increase in PM_2.5, PM₁₀, NO₂, and O₃ using modified Poisson regression.

RESULTS

In single-pollutant models, an IQR increase in PM_2.5, PM₁₀, and NO₂ during the second trimester was associated with an increased risk of depressive symptoms (PM_2.5 RR = 1.15, 95% CI: 1.04, 1.27; PM₁₀ RR = 1.13, 95% CI: 1.04, 1.23; NO₂ RR = 1.15, 95% CI: 1.03, 1.29) after adjusting for relevant covariates. Similarly, an IQR increase in O₃ during the third trimester was associated with an increased risk of depressive symptoms (RR = 1.09, 95% CI: 1.01, 1.18), while the IQR increase in O₃ during the first trimester was associated with a decreased risk (RR = 0.89, 95% CI: 0.82, 0.96). Exposure to PM_2.5, PM₁₀, and NO₂ during the second trimester was significantly associated with anxiety symptoms. The associations with PM_2.5 and O₃ in single-and multi-pollutant models were consistent.

CONCLUSIONS

Our findings indicate that increased levels of particulate matter, NO₂, and O₃ during pregnancy may elevate the risk of depression or anxiety in pregnant women.

Quantile regression analysis of the socioeconomic inequalities in air pollution and birth weight

BACKGROUND

An association between maternal exposure to air pollution and the birth weight distribution has been reported, but the extent to which this relationship varies according to socioeconomic status (SES) is unknown. This study examined the relationship using the data from a Korean birth cohort.

METHODS

Data for singleton births in Seoul from 2007 to 2017 (n = 1739) were analyzed. Maternal exposures to particulate matter with an aerodynamic diameter <10 µm (PM₁₀) and <2.5 µm (PM_2.5), as well as to nitrogen dioxide (NO₂) and ozone (O₃) for each trimester and the entire pregnancy were estimated using residential address, gestational age, and the birth date. The associations between the interquartile range (IQR) increases in pollutant concentrations and the changes in birth weight were examined using linear regression and quantile regression models. The socioeconomic disparities in the associations were investigated using a derived SES variable based on the composite of parental education and occupation. This SES variable was then interacted with the air pollutant.

RESULTS

In the gestational age-adjusted models, particulate air pollutants (PM₁₀ and PM_2.5) and O₃ were associated with birth weight decreases for the lower birth weight percentiles. For example, the decrease in mean birthweight per IQR increase in PM_2.5 during second trimester was -21.1 g (95% confidence interval (CI) = -41.8, -0.4), whereas the quantile-specific associations were: 10th percentile -27.0 g (95% CI = -46.6, -7.3); 50th percentile -22.2 g (95% CI = -39.6, -4.8); and 90th percentile -22.9 g (95% CI = -45.5, -0.2). Particulate air pollutants and O₃ showed a pattern of socioeconomic inequalities; the reduced birth weight was of greater magnitude for children from a low SES group.

CONCLUSIONS

Negative associations between particulate air pollutants and O₃ and birth weight were consistently greater at the lower quantiles of the birth weight distribution, especially in lower SES group.

Trends in Birth Weight and the Incidence of Low Birth Weight and Advanced Maternal Age in Korea between 1993 and 2016

BACKGROUND

As the aging society progresses, the average age of mothers is also increasing. Advanced maternal age has been known to be associated with perinatal outcomes, as well as birth weight (BW). In this study, we aimed to investigate the perinatal factors associated with low birth weight infants (LBWIs) using birth statistics of the Korean population.

METHODS

Birth statistics between 1993 and 2016 from the Korean Statistical Information Service were reviewed. We investigated 12,856,614 data points, which included the number of births, BWs, percentage of preterm births and LBWIs, multiple pregnancies, and maternal age.

RESULTS

The proportion of LBWIs delivered by mothers of advanced maternal age has gradually increased since 1993. In addition, the proportion of older mothers (≥ 35 years old) giving birth to LBWIs has increased over the years. Average BW has a negative correlation with the ratio of preterm births, LBW, multiple births, and advanced maternal age. The mean BW also has a negative correlation with maternal age.

CONCLUSION

This study shows that the average BW continues to decline, and the incidence of LBWIs is increasing in Korea since 1993. This study also revealed that several perinatal factors, including percentage of preterm births, LBWIs, multiple births, and maternal age influence the mean BW. Although this study did not investigate the effects of decreasing mean BW on perinatal health, future research is worth discussing.

Low birth weight in Iran: Implications from a systematic review of the literature and meta-analysis in the period 1999-2017

Background: Low birth weight (LBW), a crucial determinant of neonatal complications, represents a major public health concern worldwide. Epidemiological research is of crucial importance for designing and implementing ad hoc interventions for this issue, helping and guiding decision- and policy-makers in each country to prevent the increased prevalence of LBW in infants through estimating the prevalence rate, identifying and controlling major risk factors. The present investigation aimed to systematically assess LBW prevalence rate in Iran and its determinants. Methods: PubMed/Medline via Ovid, Embase, Web of Science and Scopus as well as Magiran, SID and Irandoc were searched from inception until November 2016. Also, the grey literature (via Google Scholar) was mined. The DerSimonian-Laird model was exploited. The I2 and Q-test tests were used to investigate heterogeneity between the studies. Sensitivity and subgroup analyses were performed to ensure the robustness and validity of our findings. Different cumulative meta-analyses were conducted stratifying according to the year of publication and sample size. Any potential bias in publication was assessed carrying out the Egger's test. Results: LBW prevalence rate was estimated to be 8% (95%CI: 7-9) in Iran. Sensitivity analysis confirmed the stability of finding. Studies were cumulated by the year of publication, and the results did not change pre- and post-cumulative meta-analysis. No publication bias could be observed. Conclusion: LBW prevalence rate in Iran is well comparable with the prevalence figures of both developed and developing countries. This could be due to the health reforms implemented in Iran throughout the years.

Association between body mass index (BMI) and duration of pregnancy in women referred to Shariati Hospital in Bandar Abbas

INTRODUCTION

Prolonged pregnancy is associated with increased risk of pregnancy complications. The role of body mass index (BMI) is not completely identified in the risk of occurrence of prolonged pregnancy. The aim of this study was to determine the association between BMI and duration of pregnancy in woman referred to the Shariati Maternity Hospital in Bandar Abbas (Hormozgan Province, Iran).

METHODS

This cross-sectional study was carried out on 1100 pregnant women referred to the Shariati Hospital in Bandar Abbas in 2015. Gestational age determined by last menstrual period (LMP) or first-trimester ultra-sonography. The women were divided into two groups of less than 40 weeks of gestation and more than 40 weeks of gestation. The women were divided based on their BMI at the first trimester of pregnancy into four groups, including less than normal, normal, overweight, and excess weight. Data were analyzed using ANOVA, Mann-Whitney test, and chi-square test by SPSS version 16.0.

RESULTS

The average age of mothers studied was 23 ± 4.30 years. Average of gestational age was 39 ± 1.85 weeks. Among the study participants 1020 (92.7%) had term pregnancies, 53 (4.8%) had preterm pregnancies, and 27 (2.5%) had post-term pregnancies. Also among the study participants, 40% had a BMI less than 19.8 kg/m², 45.9% had BMI between 19.8 and 26 kg/m², and 9.8% had BMI between 26.1 and 29 kg/m², and 4.3% had BMI less than 29 kg/m². Mean BMI was 20.95 ± 4.02 for women with gestational age of equal to or less than 40 weeks and 23.34 ± 4.52 for women with gestational age of more than 40 weeks. Duration of pregnancy was significantly higher in women with higher BMI at the first trimester (p<0.00006).

CONCLUSION

High BMI of a mother in the first trimester of pregnancy is associated with prolonged pregnancy and may increase the risk of post-term pregnancy. Women are recommended to reach an ideal weight before pregnancy to decrease the risk of the pregnancy complications.

Differences in the anthropometry of Asian children and its role in metabolic health in later life: A narrative review

BACKGROUND

The increasing incidence of childhood obesity in Asia could be a reflection of early life programming in which environmental/nutritional challenges during pregnancy and first two years of life (the so-called first 1000 days) influence later health.

OBJECTIVE OF NARRATIVE REVIEW

To assess differences/similarities of anthropometric measures in early life and their influences on metabolic health risk in later life among children in Asia.

METHODS

Literature search for publication in English using selected key words from Medline (PubMed), Scopus, Science Direct and Google Scholar published from 1994 to October 2014. Some comparisons with Caucasian setting were made when relevant.

RESULTS

From 152 publications selected for this narrative review, differences in foetal growth and birth weight were deducted between Asian and Caucasian children. Infants in India and Hong Kong had increased fat mass at birth and early infancy as compared to those from other parts of the world. Pre- and during pregnancy conditions influenced birth weight; feeding practices and gender influenced post-natal growth and body composition development. High and low birth weights followed by rapid postnatal growth were linked to increased risks of obesity, insulin resistance and high blood pressure in later life.

CONCLUSION

Foetal and postnatal growth trajectories are different between countries within and outside Asia. Extremes in birth weight followed by rapid postnatal growth were linked to increased risks of metabolic health of children in this region. As there is limited evidence in Asia, it is important to conduct thorough investigations by using longitudinal studies on early life programming.

Associations between maternal anthropometric characteristics and infant birth weight in Iranian population

Objective:

To examine the (1) normal ranges of anthropometric and insulin resistance/sensitivity indices (homeostatic model assessment for insulin resistance, homeostatic model assessment for insulin sensitivity, and quantitative insulin sensitivity check index) for Iranian pregnant women and their newborns and (2) associations between maternal anthropometric and metabolic values and infants’ birth weights among Iranian women.

Methods:

Anthropometric and metabolic values of 163 singleton non-diabetic pregnant women in Tehran, Iran (2014) were collected before and during pregnancy and at delivery. Linear regression, multivariable regression, and Student t tests were used to evaluate correlations between birth weight and maternal variables.

Results:

Linear regression modeling suggested that maternal serum glucose (p = 0.2777) and age (p = 0.6752) were not associated with birth weight. Meanwhile, maternal weight and body mass index before pregnancy (p = 0.0006 and 0.0204, respectively), weight at delivery (p = 0.0036), maternal height (p = 0.0118), and gestational age (p = 0.0016) were positively associated with birth weight, while serum insulin (p = 0.0300) and homeostatic model assessment for insulin resistance (p = 0.0334) were negatively associated with infant’s birth weight. Using multivariate modeling, we identified severalconfounders: parity (multipara mothers delivered heavier babies compared to first-time mothers) explained as much as 24% of variation in birth weight (p = 0.005), maternal height explained 20.7% (p = 0.014), gestational age accounted for 19.7% (p = 0.027), and maternal body mass index explained 19.1% (p = 0.023) of the variation in the infant’s birth weight. Maternal serum insulin and infant’s sex were not observed to be associated with birth weight (p = 0.342 and 0.669, respectively) in the overall model.

Conclusion:

Overweight/obese women may experience higher incidence of delivering larger babies. Multivariable regression analyses showed that maternal body mass index and height, parity, and gestational age are associated with newborn’s birth weight.

The effect of perinatal anxiety on bronchiolitis is influenced by polymorphisms in ROS-related genes

Background

Exposure to perinatal anxiety affects disease susceptibility in offspring but studies on the association between perinatal anxiety and gene polymorphisms are lacking. This study aimed to elucidate the interaction between perinatal anxiety and polymorphisms in antioxidant defense and innate immunity genes on the development of respiratory tract infections (RTIs) during early infancy.

Methods

Trait anxiety levels in 440 women were assessed by the State-Trait Anxiety Inventory during late gestation. The occurrence of RTIs, including bronchiolitis, during the first year of life was assessed by parent-reported doctor diagnosis. Polymorphisms in glutathione S-transferase P-1 (GSTP1, rs1695) and CD14 (rs2569190) were genotyped using the TaqMan assay. Copy number variations of GSTT1 were measured by real-time polymerase chain reaction.

Results

Exposure to high levels of perinatal anxiety increased the risk of bronchiolitis in the first year of life (adjusted odds ratio [aOR], 1.30; 95% confidence interval [CI]: 1.00–1.80), in particular among children with the AG + GG genotype of GSTP1 or the GSTT1 null genotype (aOR 3.36 and 2.79). In infants with the TC + CC genotype of CD14, high levels of perinatal anxiety were associated with an increased risk of upper RTI, lower RTI, and bronchiolitis (aOR 2.51, 4.60, and 4.31, respectively).

Conclusions

Perinatal maternal anxiety levels affect the occurrence of bronchiolitis in offspring. The effect of perinatal anxiety on the occurrence of bronchiolitis during infancy was influenced by genetic polymorphisms in antioxidant defense and innate immunity genes.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2466-14-154) contains supplementary material, which is available to authorized users.

Prenatal maternal depression is associated with low birth weight through shorter gestational age in term infants in Korea

BACKGROUND

Maternal prenatal depression is associated with lower offspring birth weight, yet the impact of gestational age on this association remains inadequately understood.

AIMS

We aimed to investigate the effect of prenatal depression on low birth weight, gestational age, and weight for gestational age at term.

STUDY DESIGN

Prospective cohort study.

SUBJECT

Data were collected from 691 women in their third trimester of pregnancy who went on to give birth to a singleton at term without perinatal complications. One hundred and fifty-two women had a Center for Epidemiologic Studies Depression Scale-10 score ≥10 and were classed as prenatally depressed.

OUTCOME MEASURES

Low birth weight (<2500g), gestational age at birth, and birth weight percentile for gestational age.

RESULTS

Offspring of prenatally depressed women were more likely to be low birth weight (Odds ratio [OR] 2.94, 95% confidence interval [CI] 1.14-7.58) than offspring of prenatally non-depressed women, but the association was attenuated (OR 1.66, 95% CI 0.55-5.02) when adjusted for gestational age. Offspring of prenatally depressed women had lower gestational age in weeks (OR for one week increase in gestational age: 0.66, 95% CI 0.47-0.93) than offspring of prenatally non-depressed women. There was no association between prenatal depression and birth weight percentile for gestational age.

CONCLUSIONS

Prenatal depression was not associated with low birth weight at term, but was associated with gestational age, suggesting that association between maternal depression and birth weight may be a reflection of the impact of depression on offspring gestational age.

Associations of maternal and neonatal serum trace element concentrations with neonatal birth weight

BACKGROUND

Trace elements play important nutritional roles in neonates. Our objective was to examine whether there are differences in maternal/neonatal serum trace element concentrations between mature infants and premature infants.

METHODS

During 2012, 44 infants born at National Center for Global Health and Medicine, Tokyo, Japan, were enrolled. Serum samples were collected to measure serum iron, zinc, copper, and selenium concentrations 5 days after birth. Maternal serum samples were obtained before delivery and cord blood was taken at delivery to measure the same trace elements. We compared the results between term group whose birth weight were ≥2500 g and gestational age were ≥37 weeks and premature group whose birth weight were <2500 g or gestational age were <37 weeks. Variables significantly different between two groups were included in linear regression models to identify significant predictors of birth weight. Values of P<0.05 were considered statistically significant.

RESULTS

Serum selenium concentrations were lower in premature group than in term group (43.3±7.0 µg/L vs. 52.0±8.9 µg/L, P = 0.001). Maternal serum selenium concentrations were also significantly lower in the mothers of premature group than in the mothers of term group (79.3±19.3 µg/L vs. 94.1±18.1 µg/L, P = 0.032). There were no significant differences in neonatal or maternal iron, zinc, or copper concentrations between two groups. Multivariate linear regression analysis showed that, except for gestational age, only maternal serum selenium was significantly associated with birth weight (P = 0.015).

CONCLUSIONS

Serum selenium concentrations were lower in premature group and their mothers compared with the term group. The maternal serum selenium concentration was positively correlated with birth weight. These results suggest that maternal serum selenium concentration may influence neonatal birth weight.