Prenatal ambient air pollutants exposure and the risk of stillbirth in Wuhan, central of China.

BACKGROUND: The existing studies on the relationships of prenatal ambient air pollutants exposure with stillbirth in the Chinese population are very limited and the results are inconsistent, and the susceptible windows and potential modifiers for air pollutants exposure on stillbirth remain unanswered. OBJECTIVE: We aimed to determine the relationships between exposure to ambient air pollutants and stillbirth, and explored the susceptible windows and potential modifiers for air pollutants exposure on stillbirth. METHODS: A population-based cohort was established through the Wuhan Maternal and Child Health Management Information System involving 509,057 mother-infant pairs in Wuhan from January 1, 2011 through September 30, 2017. Personal exposure concentrations of fine particles (PM2.5), inhalable particles (PM10), sulfur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO), and ozone (O3) for mothers were estimated based on their residential address during pregnancy using the inverse distance weighted (IDW) method. We used the logistic regression models to determine the associations at different stages of pregnancy with adjustment for confounding factors. RESULTS: There were 3218 stillbirths and 505,839 live births among the participants. For each 100 µg/m3 of CO and 10 µg/m3 of O3 increase in the first trimester (conception to 13+6 weeks), the risk of stillbirth increased by 1.0% (OR = 1.01, 95%CI: 1.00-1.03) and 7.0% (OR = 1.07, 95%CI: 1.05-1.09). In the second trimester (14 weeks-27+6 weeks), PM2.5, PM10, CO, and O3 exposure were closely related to the risk of stillbirth (P＜0.05). In the third trimester (28 weeks to delivery), for each 10 µg/m3 increase in exposure concentrations of PM2.5, SO2, and O3, the risk of stillbirth increased by 3.4%, 5.9%, and 4.0%, respectively. O3 exposure was positively relevant to the risk of stillbirth (OR = 1.11, 95%CI: 1.08-1.14) in the whole pregnancy. Exposure to NO2 was not significantly associated with the risk of stillbirth. Stratified analyses also presented a stronger association among mothers with boy infant, living in rural areas, delivering between 2011 and 2013, and those without gestational hypertension and history of stillbirth. CONCLUSION: This study provides evidence that maternal exposure to PM2.5, PM10, SO2, CO, and O3 were related to the increased risk of stillbirth. Both the second and third trimesters might be vital susceptible windows for stillbirth. Our findings expand the evidence base for the important impacts of air pollution on fetal growth.

Prenatal exposure to air pollutants and early childhood growth trajectories: A population-based prospective birth cohort study.

BACKGROUND: Air pollution exposure during pregnancy has been documented to be associated with impaired fetal growth and adverse birth outcomes, but the evidence regarding the effects of air pollution on early childhood growth is still limited. OBJECTIVE: We aimed to explore the associations of exposure to air pollutants during pregnancy with childhood growth trajectories from birth to age of 6 years. METHODS: A prospective cohort study based on the administrative registration system was conducted covering 62,540 births in Wuhan, China between January 1, 2011 and December 31, 2013 and followed for 6 years. Inverse distance weighted method was used to estimate the concentrations of air pollutants exposure for pregnant women. Group-based trajectory models (GBTM) were used to identify growth patterns of children: slow growth, normal growth, and rapid growth. Multinomial logistic regression models were used to examine the associations between prenatal exposure to air pollutants and childhood growth trajectories with adjustment for maternal age, educational status, pre-pregnancy BMI, residential areas, gestational diabetes, birth type, gender of infant, and breastfeeding duration. RESULTS: The mean (SD) of prenatal exposure concentrations for PM10, SO2, NO2, CO, and O3 were 107.9 (30.4), 32.8(12.6), 55.8(13.1), 1081.2(293.1), and 81.6(31.0) µg/m3 respectively. Compared with normal growth trajectory, increased PM10 and CO exposure were significantly associated with higher risk of slow growth trajectory but lower risk of rapid growth trajectory. An increase in prenatal exposure to NO2 significantly increased both the risk of slow growth trajectory and rapid growth trajectory. Increased prenatal SO2 exposure was significantly associated with rapid growth trajectory and was not associated with low growth trajectory. With O3 exposure levels increased, risk to be rapid growth trajectory decreased. Prenatal air pollutants exposure had a greater impact on childhood growth of children who were girls, and those mothers lived in rural areas and were normal weight before pregnancy. CONCLUSIONS: High levels of air pollutants exposure during pregnancy were associated with the risk of being in a trajectory with the deviation of BMI gain from birth to 6 years old. These findings suggest that efforts to identify children at risk of growth deviation in early childhood should pay attention to environmental exposure during pregnancy for their mothers.

Task switching costs in preschool children and adults.

Past research investigating cognitive flexibility has shown that preschool children make many perseverative errors in tasks that require switching between different sets of rules. However, this inflexibility might not necessarily hold with easier tasks. The current study investigated the developmental differences in cognitive flexibility using a task-switching procedure that compared reaction times and accuracy in 4- and 6-year-olds with those in adults. The experiment involved simple target detection tasks and was intentionally designed in a way that the stimulus and response conflicts were minimal together with a long preparation window. Global mixing costs (performance costs when multiple tasks are relevant in a context), and local switch costs (performance costs due to switching to an alternative task) are typically thought to engage endogenous control processes. If this is the case, we should observe developmental differences with both of these costs. Our results show, however, that when the accuracy was good, there were no age differences in cognitive flexibility (i.e., the ability to manage multiple tasks and to switch between tasks) between children and adults. Even though preschool children had slower reaction times and were less accurate, the mixing and switch costs associated with task switching were not reliably larger for preschool children. Preschool children did, however, show more commission errors and greater response repetition effects than adults, which may reflect differences in inhibitory control.

The Wuhan Twin Birth Cohort (WTBC).

The Wuhan Pre/Post-Natal Twin Birth Registry (WPTBR) is one of the largest twin birth registries with comprehensive medical information in China. It recruits women from the first trimester of pregnancy and their twins from birth. From January 2006 to May 2016, the total number of twins enrolled in WPTBR is 13,869 twin pairs (27,553 individuals). The WPTBR initiated the Wuhan Twin Birth Cohort (WTBC). The WTBC is a prospective cohort study carried out through incorporation of three samples. The first one comprises 6,920 twin pairs, and the second one, 6,949 twin pairs. Both are population-based samples linked to the WPTBR and include pre- and post-natal information from WPTBR. The second sample includes neonatal blood spots as well. Using a hospital-based approach, we recently developed a third sample with a target enrolment of 1,000 twin pairs and their mothers. These twins are invited, via their parents, to participate in a periodic health examination from the first trimester of pregnancy to 18 years. Biological samples are collected initially from the mother, including blood, urine, cord blood, cord, amniotic fluid, placenta, breast milk and meconium, and vaginal secretions, and later from the twins, including meconium, stool, urine, and blood. This article describes the design, recruitment, follow-up, data collection, and measures, as well as ongoing and planned analyses at the WTBC. The WTBC offers a unique opportunity to follow women from prenatal to postnatal, as well as follow-up of their twins. This cohort study will expand the understanding of genetic and environmental influences on pregnancy and twins' development in China.

Relationship Between Common Mental Disorder Symptoms During Pregnancy and Preterm Birth Among Chinese Women in Wuhan.

Objectives Few studies focus on the symptoms of common mental disorders during pregnancy (CMDP) and risk of preterm birth subtypes (PTB). The purpose of this study was to estimate the association between CMDP and PTB, and to examine whether or not the association between CMDP and PTB varies with the subtype of PTB in Chinese. Methods This population-based case control study, conducted in Wuhan, China, defined cases as every pregnant woman who had a PTB among all births in Wuhan, from June 10, 2011, to June 9, 2013. The same number of pregnant women who had term births was randomly selected as controls. The Electronic Perinatal Health Care Information System, a questionnaire designed for the study, provided data about the participants. Logistic regression analyses were used to model associations between CMDP and PTB, and to test associations between CMDP and two subtypes of PTB. Results The study recruited 8616 cases and an equal number of controls. We successfully collected maternal information on 6656 cases and controls for a response rate of 77.3 %. The incidence of PTB in Wuhan was 4.5 %. Spontaneous preterm births (SPTB) accounted for 60.1 %, and medically induced preterm births (IPTB) accounted for 39.9 % of preterm births. The prevalence rate of CMDP was 15.8 %. CMDP was slightly associated with PTB (crude OR 1.16, 95 % CI 1.01-1.32; adjusted OR 1.15, 95 % CI 1.00-1.32), further analyses showed CMDP was associated with IPTB (aOR 1.25, 95 % CI 1.04-1.50), but not with SPTB. Conclusion Our data suggest that CMDP is related to an increased risk of PTB, and that this association is primarily due to IPTB rather than SPTB.

Prenatal exposure to PM2.5 and childhood body mass index growth trajectories from birth to 6 years old.

This study aimed to determine the relationships between prenatal PM2.5 exposure and childhood growth trajectories during the first 6 years of life. A total of 47,625 pairs of mothers and children were recruited from a prospective birth cohort conducted between 2011 and 2013 in Wuhan, China, and followed for 6 years. We used the group-based trajectory models to classify the population into three trajectory groups: slow growth (n = 13,671, 28.7%), normal growth (n = 29,736, 62.4%), and rapid growth (n = 4218, 8.9%). Multinomial logistic regression models were used to determine the associations of prenatal PM2.5 exposure and childhood growth trajectories. Compared to normal growth trajectory, increased PM2.5 exposure in trimester 1, trimester 2 and the entire pregnancy showed significant associations with an increased risk of the slow growth trajectory but reduced the risk for the rapid growth trajectory, significant association of prenatal PM2.5 exposure with rapid growth trajectory was only observed in the trimester 3. Stratified analyses displayed relatively stronger associations among those mothers with maternal age over 35 years, pre-pregnancy BMI ≥ 25 kg/m2, and previous delivery experience. Prenatal exposure to PM2.5, particularly during the midpoint period of pregnancy, was more likely to have a slow growth trajectory and a lower risk of rapid growth trajectory. Maternal age, pre-pregnancy BMI, and previous delivery experience might modify these associations.

Social anxiety and suicidal ideation among middle-school students in China: a mediation model of internet addiction.

Background: Suicide is a fatal public health issue for adolescents, and it is of great significance to explore the precursors of suicidal behaviors, especially suicidal ideation. However, the relationship between social anxiety and suicidal ideation and its mechanism are still unclear. The study aims to examine the association between social anxiety and suicidal ideation and the mediating effect through Internet addiction. Methods: A total of 2,278 middle-school students aged 12 to 16 years were recruited through a multistage cluster sampling method in this cross-sectional study. Logistical regression analysis and structural equation modeling (SEM) were conducted to examine the direct and indirect effects of social anxiety. Results: During the past year, 262 (11.50%) participants reported suicidal ideation. Females had a higher prevalence of suicidal ideation than males (12.9% vs. 10.0%, p = 0.034), and urban adolescents reported a higher prevalence than their rural counterparts (13.4% vs. 9.6%, p = 0.006). In the total sample, social anxiety and Internet addiction were independently associated with suicidal ideation (p < 0.05). In the subgroup analysis, the association between social anxiety and suicidal ideation was significant only among rural females and urban males (p < 0.05). SEM demonstrated that social anxiety had direct and indirect effects on suicidal ideation, and Internet addiction partially mediated the relationship, with a mediating ratio of 30.53%. The partial mediating effect was also significant only in rural females and urban males. Conclusion: Adolescents may overuse the Internet to cope with social anxiety and further have suicidal ideation. Limiting Internet use and improving interpersonal skills in real life may be efficient for suicide prevention. In addition, targeted interventions should be tailored by different sexes across urban and rural regions.

Association between short- and long-term exposures to air pollutants and internalizing/externalizing behavior in children aged 4 to 7 years.

The effects of air pollutants on psychological health have attracted increasing attention worldwide. However, there is limited evidence on the association between air pollution and children's psychological development. This study explores the association between short- and long-term exposures to air pollutants and children's internalizing and externalizing behaviors. A total of 2303 children of 4-7 years were included in this study. We assessed their behavior using the Child Behavior Checklist (4-16 years). The prevalence of internalizing and externalizing behavior was 4.77% and 4.43%, respectively. For short-term exposure, CO pollution was associated with children's internalizing behaviors, with each 1 mg/m3 increment leading to an odds ratio (OR) of 1.063 (95% CI 1.005, 1.124), 1.065 (95% CI 1.009, 1.124), 1.067 (95% CI 1.007, 1.131), and 1.122 (95% CI 1.018, 1.236) at lag04, lag05, lag06, and lag0120, respectively. O3 (per 1 g[Formula: see text]/m3) was negatively associated with internalizing problems at lag2 [OR = 0.991 (95% CI 0.983, 0.999)]. NO2 (per 1 g[Formula: see text]/m3) was significantly associated with externalizing behaviors, with the ORs of 1.067 (95% CI 1.024, 1.111) at lag060 and 1.060 (95% CI 1.010, 1.113) at lag0120. For long-term exposure, it indicated that 1-year exposure to CO (per 1 mg/m3) and PM2.5 (per 1 g[Formula: see text]/m3) was positively associated with internalizing behavioral risk [OR = 1.724 (95% CI 1.187, 2.504); PM2.5: OR = 1.236 (95% CI 1.114, 1.371)], whereas NO2 (per 1 g[Formula: see text]/m3) exposure was associated with an increased risk of externalizing behavior [OR = 1.123 (95% CI 1.003, 1.256)]. In addition, the interaction analysis showed that boys were at a higher risk of abnormal behaviors associated with long-term exposure to CO, PM2.5, and NO2. Our findings reveal a potential link between air pollution exposure and abnormal behaviors in kindergarten children after short-/long-term exposure, which is an essential supplement to the studies on the association between air pollution and children's behavioral problems.

Gut Microbiota Diversity and Overweight/Obesity in Infancy: Results from a Nested Case-control Study.

OBJECTIVE: Childhood obesity is a major health concern worldwide. Previous studies have explored the relationship between obesity and gut microbiota. However, the results from such studies remain contradictory. METHODS: In the present nested case-control study, based on a twin birth cohort study, the relationship between gut microbiota diversity and overweight/obesity in 1- and 6-month-old infants was explored. Twins were enrolled when one child had normal weight and the other child was overweight/obese at six months old. For both infants, stool samples were collected at 1 and 6 months of age. Finally, 12 twins were enrolled in the study. The gut microbiota was identified by 16S rRNA gene sequencing in the V3-V4 area. Six of the twins were monozygotic. RESULTS: The results revealed that the microbiota communities of monozygotic twins were similar to those of dizygotic twins. The relative abundance (RA) of microbiota of 1-month-old twins was significantly higher than that of 6-month-old twins. However, the microbiota diversity of 1-month-old twins was significantly lower than that of 6-month-old twins. In addition, 6-month-old twins had significantly higher RA levels of Bifidobacterium and Lachnospiracea incertae sedis than 1-month-old twins. The 6-month-old group had significantly lower RA levels of Veillonella, Klebsiella, Akkermansia, Streptococcus, or Staphylococcus than the 1-month-old group. At six months, the RA level of Clostridium sensu stricto was higher in the overweight/obesity group than the normal-weight group. CONCLUSION: These findings imply that changes in gut microbiota diversity during infancy may contribute to the development of obesity in early infancy.

Development of the gut microbiota in healthy twins during the first 2 years of life and associations with body mass index z-score: Results from the Wuhan twin birth cohort study.

The gut microbiota undergoes rapid and vital changes to microbial community structure and the microbial-immune crosstalk during the first 3 years of life, which is thought to be involved in the pathobiology of later-life disease. Compared to single-born children, little is known about the gut microbiota of twins in early childhood. Based on the Wuhan Twin Birth Cohort study, 344 stool samples from 204 twin families were analyzed to investigate the difference in gut microbiota composition at 6, 12, and 24 months of age. Furthermore, this study evaluated the association between gut microbiota development curves and body mass index z-score (BMI_Z) curves at 6, 12, and 24 months of age. The predominant microbiota phyla identified in twins were Proteobacteria, Actinobacteriota, Firmicutes, Bacteroidota, and Verrucomicrobiota. The richness and diversity of gut microbiota increased from 6 to 24 months old (alpha diversity with p < 0.05). Beta diversity revealed 61 gut microbiota genera that were significantly different in relative abundance among the three age groups. Among the 61 gut microbiota genera, 30 distinct trajectory curves (DTCs) were generated by group-based trajectory models after log2 transformation of their relative abundance. Subsequently, Spearman correlation analysis revealed that only five gut microbiota DTC were correlated with the BMI_Z DTC. Therefore, we further examined the association between the five gut microbiota genera DTC and BMI_Z DTC using generalized estimation equation models. The results revealed a significant association between the DTC groups of Parabacteroides and that of BMI_Z (coefficient = 0.75, p = 0.04). The results of this study validated the hypothesis that the richness and diversity of gut microbiota developed with age in twins. Moreover, participants with a higher DTC of log2-transformed Parabacteroides had a higher BMI_Z DTC during the first 2 years of life. Further studies are needed to confirm the association between Parabacteroides and BMI_Z in other populations.

Association between maternal family history of hypertension and preterm birth: modification by noise exposure and multivitamin intake.

OBJECTIVE: To measure the effect of maternal family history of hypertension on preterm birth (PTB) and to identify factors that modified this association. METHODS: A case-control study was nested in a prospective cohort of the entire pregnant population in Wuhan, China, from 2011 to 2013. Home-visit interviews were scheduled for all PTBs and their controls, to collect extensive information on maternal exposures to behavioral, environmental, and intergenerational risk factors of PTB. The effects of maternal family history of hypertension on PTB were measured by logistic regression analyses, controlling for potential confounders. Potential effect modifiers were examined using stratified analyses. RESULTS: There were 2393 PTBs and 4263 full-term births out of all eligible births. A positive association was observed between maternal family history of hypertension and PTB, after adjusted for potential confounders (adjusted odds ratio: 1.17 [1.03, 1.33]). A higher effect was observed when mothers were exposed to certain noise during pregnancy (adjusted odds ratio: 1.37 [1.14, 1.65]) and/or when they did not take multivitamins during pregnancy (adjusted odds ratio: 1.46 [1.20, 1.78]), whereas, this association was weaker and no longer significant when mothers took multivitamins during pregnancy (adjusted odds ratio: 1.00 [0.84, 1.19]) and/or when they were not exposed to certain noise during pregnancy (adjusted odds ratio: 1.01 [0.85, 1.12]). The modification effect from maternal multivitamin intake was significant on both spontaneous and medically indicated PTBs, and the modification effect from maternal exposure to certain noise was only significant on spontaneous PTB. CONCLUSIONS: Increased PTB risk was observed for pregnant women with a family history of hypertension in Wuhan, China. This effect was stronger when pregnant women did not take multivitamin and/or exposed to certain noise during pregnancy, than those who took multivitamin and/or unexposed to certain noise.

Comparative study on different strategies for synthesizing all-silica DD3R zeolite crystals with a uniform morphology and size.

In the last three decades, the all-silica deca-dodecasil 3R (DD3R) zeolite has been extensively studied as a significant potential class of porous materials in adsorptive separations. However, the use of most existing synthesis methods is unable to produce pure DD3R crystals with a uniform morphology and size. The present research, is therefore intended to provide a facile protocol to synthesize pure DD3R crystals with a controllable morphology and size and with a high reproducibility and productivity. Special attention was focused on investigating the effects of the type of seeds and the mineralizing reagent on the phase-purity, morphology, and crystal size of the resultant DD3R crystals. Various techniques, such as X-ray diffraction (XRD), scanning electron microscopy (SEM), N2 adsorption-desorption at 77 K, and thermogravimetric analysis (TGA) were then used to characterize the synthesized samples. The results show that by adding a small amount of "amorphous" DD3R or "amorphous" ZSM-58 seeds, the pure DD3R crystals with a uniform morphology and size can be synthesized using 1-adamantanamine (1-ADA) as a structure-directing agent (SDA), KF was used as a mineralizing reagent, and LUDOX AS-30 as a silicon source at 443 K for 1 d. In addition, the pure, large and uniform hexahedron DD3R crystals can be prepared using fumed silica as seeds, although the crystallization time takes a longer period of 3 d. The present work could stimulate fundamental research and industrial applications of the all-silica DD3R zeolite.

Associations of exposure to green space with problem behaviours in preschool-aged children.

BACKGROUND: Limited evidence is available regarding the association of green-space exposure with childhood behavioural development. This study aimed to investigate the associations of exposure to green space with multiple syndromes of behavioural development in preschool children. METHODS: This cross-sectional study was conducted in Wuhan, China from April 2016 to June 2018. We recruited a sample of 6039 children aged 5-6 years from 17 kindergartens located in five urban districts of the city. We measured the greenness using average Normalized Difference Vegetation Index (NDVI) within a circular buffer area of 100 metres surrounding the central point of residences and kindergartens. We calculated the residence-kindergarten-weighted greenness by assuming that children spent 16 hours per day at home and 8 hours at kindergarten. The problem behaviours of children were evaluated at kindergarten using the Childhood Behavioral Checklist (CBCL) and standardized into problem behavioural T scores. Linear mixed-effect models and linear-regression models were used to estimate the associations. RESULTS: We observed decreases in problem behaviours associated with kindergarten and residence-kindergarten-weighted surrounding greenness in preschool children. For example, a one-interquartile range increase in kindergarten and residence-kindergarten-weighted NDVI was associated with decreased T scores for total behaviour by -0.61 [95% confidence interval (CI): -1.09, -0.13) and -0.49 (95% CI -0.85, -0.12), anxiety and depression by -0.65 (95% CI: -1.13, -0.17) and -0.46 (95% CI: -0.82, -0.10), aggressive behaviour by -0.53 (95% CI: -1.01, -0.05) and -0.38 (95% CI: -0.75, -0.02) and hyperactivity and attention deficit by -0.54 (95% CI: -1.01, -0.07) and -0.48 (95% CI: -0.83, -0.12), respectively. Stratified analyses indicated that the associations of green-space exposure with problem behaviours were stronger in boys than in girls. CONCLUSIONS: Children attending kindergartens with higher levels of surrounding green space exhibited better behavioural development. The mechanisms underlying these associations should be explored further.

Risks of maternal prepregnancy overweight/obesity, excessive gestational weight gain, and bottle-feeding in infancy rapid weight gain: evidence from a cohort study in China.

Rapid weight gain (RWG) in infants is associated with numerous health problems, and its risk factors are still unclear. We assessed 98,097 maternal-infant pairs from a population-based cohort study and followed up with them until the infants were 6 months old. We assessed the associations between maternal prepregnancy weight status; gestational weight gain; feeding pattern; and infants' RWG at 0-1, 0-3, 1-3, and 3-6 months using multivariate unconditional logistic regression models, with controlled confounders. We found that maternal prepregnancy weight status, gestational weight gain, and feeding pattern at the 1st, 3rd, and 6th months had significant impacts on the infants' RWG at each time period (P<0.05). Infants with overweight/obese mothers had a higher risk of RWG after birth, whereas those of mothers who experienced excessive gestational weight gain had higher risks of RWG from birth than the other groups (P<0.01). Infants who were formula-fed had a higher risk of RWG than breastfed infants at the same time point (P<0.01). In conclusion, maternal prepregnancy obesity, excessive gestational weight gain, and formula-feeding were risk factors for infants' RWG during the first 6 months of life.

Information processes of task-switching and modality-shifting across development.

Developmental research on flexible attentional control in young children has often focused on the role of attention in task-switching in a unimodal context. In real life, children must master the art of switching attention not only between task demands, but also between sensory modalities. Previous study has shown that young children can be efficient at switching between unimodal tasks when the situation allows, incurring no greater task-switching costs than adults. However, young children may still experience a greater demand to shift attention between modalities than older participants. To address this, we tested 4-year-olds, 6-year-olds and adults on a novel cross-modal task-switching paradigm involving multisensory detection tasks. While we found age differences in absolute reaction time and accuracy, young children and adults both exhibited strikingly similar effects in task-switching, modality-shifting, and the interaction between them. Young children did not exhibit a greater attentional bottleneck on either the task level, or on the modality level; thus, the evidence suggests that young children engaged in similar cognitive operations in the current cross-modal tasks to adult participants. It appears that cognitive operations in multisensory task configuration are relatively mature between 4 and 6 years old.

Ambient air pollution the risk of stillbirth: A prospective birth cohort study in Wuhan, China.

BACKGROUND: Recent studies suggest that ambient air pollution exposure during pregnancy is associated with stillbirth occurrence. However, the results on the associations between ambient air pollutants and stillbirths are inconsistent and little is known about the gestational timing of sensitive periods for the effects of ambient air pollutants exposure on stillbirth. OBJECTIVE: This study aimed to examine whether exposure to high levels of ambient air pollutants in a Chinese population is associated with an increased risk of stillbirth, and determine the gestational period when the fetus is most susceptible. METHODS: We conducted a population-based cohort study in Wuhan, China, involving 95,354 births between June 10, 2011 and June 9, 2013. The exposure assessments were based on the daily mean concentrations of air pollutants obtained from the exposure monitor nearest to the pregnant women's residence. Logistic regression analyses were performed to determine the associations between stillbirths and exposure to each of the air pollutants at different pregnancy periods with adjustment for confounding factors. RESULTS: Stillbirth increased with a 10 µg/m3 increase in particulate matter 2.5 (PM2.5) in each stage of pregnancy, and a significant association between carbon monoxide (CO) exposure and stillbirth was found during the third trimester (adjusted odds ratio (aOR): 1.01, 95% confidence interval (CI): 1.00-1.01) and in the entire pregnancy (aOR: 1.18, 95% CI: 1.04-1.34). Furthermore, an increased risk of stillbirth in the third trimester was associated with a 10 µg/m3 increase in PM10 (aOR: 1.08, 95% CI: 1.04-1.11), nitrogen dioxide (NO2) (aOR: 1.13, 95% CI: 1.07-1.21) and sulfur dioxide (SO2) (aOR: 1.26, 95% CI: 1.16-1.35). However, no positive association was observed between ozone exposure and stillbirth. In the two-pollutant models, PM2.5 and CO exposures were found to be consistently associated with stillbirth. CONCLUSIONS: Our study revealed that exposure to high levels of PM2.5, PM10, SO2, NO2 and CO increases the risk of stillbirth and the most susceptible gestational period to ambient air pollution exposure was in the third trimester. Further toxicological and prospective cohort studies with improved exposure assessments are needed to confirm the causal link between air pollutants and stillbirth.

Pre-Pregnancy Body Mass Index, Gestational Weight Gain, and Birth Weight: A Cohort Study in China.

OBJECTIVE: To assess whether pre-pregnancy body mass index (BMI) modify the relationship between gestational weight gain (GWG) and child birth weight (specifically, presence or absence of low birth weight (LBW) or presence of absence of macrosomia), and estimates of the relative risk of macrosomia and LBW based on pre-pregnancy BMI were controlled in Wuhan, China. METHODS: From June 30, 2011 to June 30, 2013. All data was collected and available from the perinatal health care system. Logistic regression models were used to estimate the independent association among pregnancy weight gain, LBW, normal birth weight, and macrosomia within different pre-pregnancy BMI groups. We built different logistic models for the 2009 Institute of Medicine (IOM) Guidelines and Chinese-recommended GWG which was made from this sample. The Chinese-recommended GWG was derived from the quartile values (25th-75th percentiles) of weight gain at the time of delivery in the subjects which comprised our sample. RESULTS: For LBW children, using the recommended weight gain of the IOM and Chinese women as a reference, the OR for a pregnancy weight gain below recommendations resulted in a positive relationship for lean and normal weight women, but not for overweight and obese women. For macrosomia, considering the IOM's recommended weight gain as a reference, the OR magnitude for pregnancy weight gain above recommendations resulted in a positive correlation for all women. The OR for a pregnancy weight gain below recommendations resulted in a negative relationship for normal BMI and lean women, but not for overweight and obese women based on the IOM recommendations, significant based on the recommended pregnancy weight gain for Chinese women. Of normal weight children, 56.6% were above the GWG based on IOM recommendations, but 26.97% of normal weight children were above the GWG based on Chinese recommendations. CONCLUSIONS: A GWG above IOM recommendations might not be helpful for Chinese women. We need unified criteria to classify adult BMI and to expand the sample size to improve representation and to elucidate the relationship between GWG and related outcomes for developing a Chinese GWG recommendation.

[Risk factors for otitis media with effusion in children].

OBJECTIVE: To identify the risk factors for otitis media with effusion (OME) in some kindergarten children in Wuhan City of China and analyze the results with reference to the review of the literature. METHODS: The study subjects were 3 to 6 years old children drawn from a school screening program for OME in Wuhan. All subjects were assessed with routine otorhinolaryngologic examination, otoscopic examination and tympanometry. During the test, parents were interviewed to provide information with regard to the children's birth history, neonatal history, feeding history, family smoke history, otological history, rhinorrhea, sneeze, nasal obstruction, snoring, tonsillitis episodes history, et al. These data formed the basis in the estimation of potential risk factors for OME. RESULTS: In the univariate analysis of 144 cases and 288 controls, significantly elevated odds ratios (OR) for OME were detected on the symptoms of nasal obstruction (OR = 2.60, P = 0.002), rhinorrhoea (OR = 1.442, P = 0.003), high hard palate (OR = 4.411, P < 0.0001), and previous history of acute otitis media (OR = 1.77, P = 0.025). However, four factors were found to be significant in the multivariate logistic regression model, including feeding history (OR = 0.746, P = 0.047), nasal obstruction (OR = 2.56, P = 0.003) and previous acute otitis media episodes (OR = 1.735, P = 0.032). CONCLUSIONS: Previous acute otitis media episodes and nasal obstruction were risk factors, which was accordant with literature. In addition, breastfeeding was a protective factor for OME, but acute tonsillitis was not a factor for OME. A child who had previous acute otitis media episode and often had nasal obstruction is suggested to have otorhinolaryngologic regulatory examination.