Association between Dietary Patterns during Pregnancy and Children's Neurodevelopment: A Birth Cohort Study.

BACKGROUND: Research studies have showed that maternal diet may influence fetal neurodevelopment, but most studies have only assessed single nutrients or food groups. OBJECTIVE: To investigate the impact of maternal prenatal dietary patterns during pregnancy on child neurodevelopment. METHODS: Study participants were obtained from the China National Birth Cohort. The Ages and Stages Questionnaire, Third Edition, was used to assess children's neurodevelopment at 36 months old. Maternal antenatal dietary data were collected over three trimesters using food frequency questionnaires. Five distinct maternal dietary patterns throughout pregnancy were identified by principal component analysis, namely protein- and micronutrient-rich dietary patterns, low-iron dietary patterns, pasta as the staple food dietary patterns, iron-rich dietary patterns, tubers, fruits, and baked food dietary patterns. Group-based trajectory modeling was performed for dietary patterns present in all three periods. Multiple linear regression models were used for statistical analysis. RESULTS: Children of mothers who followed a high protein- and micronutrient-rich dietary pattern trajectory during pregnancy presented better neurodevelopment, including higher gross motor and problem-solving scores. Furthermore, it was observed that children born of women with low-iron dietary patterns had poorer neurodevelopment. In detail, children born to mothers with a low-iron dietary pattern during the first trimester had lower problem-solving scores, while to those who were exposed to a low-iron dietary pattern in the second and third trimesters had lower gross motor scores. Additionally, children with mothers who had a low-iron dietary pattern in the third trimester had lower communication scores. CONCLUSIONS: A nutrition-balanced protein- and micronutrient-rich dietary pattern and adequate iron dietary pattern for mothers throughout pregnancy may be beneficial to children's neurodevelopment.

No role of the third-trimester inflammatory factors in the association of gestational diabetes mellitus with postpartum cardiometabolic indicators.

BACKGROUND: The influence of gestational diabetes mellitus (GDM) on postpartum cardiometabolic indicators is primarily restricted to glucose and lipid metabolism, however the indicators for liver and kidney function have been rarely explored, and the role of the third-trimester inflammatory factors in these associations has never been investigated. METHODS: Based on the Ma'anshan birth cohort (MABC), women with or without GDM history were selected and invited to participate in a 6-year postpartum follow-up. The fasting blood samples were collected to measure 16 comprehensive metabolic indicators during a 6-year postpartum follow-up: fasting plasma glucose (FPG), glycosylated hemoglobin (HbA1c), triglycerides (TG), total cholesterol (TC), uric acid (UA), blood urea nitrogen (BUN), serum creatinine (SCR), etc. Seven inflammatory factors, including TNF-α, IFN-γ, IL-1ß, IL-6, IL-10, IL-12p70, and IL-17 A, were measured with serum samples collected during the third trimester of pregnancy. Linear regression models were used to analyze the associations between GDM and 6-year postpartum metabolic indicators, GDM and third-trimester inflammatory factors, and the third-trimester inflammatory factors and 6-year postpartum metabolic indicators. Mediating and moderating effect analyses were further performed to explore if the third-trimester inflammatory factors mediate or modify the association between GDM and postpartum cardiometabolic indicators. RESULTS: From July 2021 to August 2022, 307 participants have been followed up, with 99 women with a prior GDM history. Compared with those without GDM, individuals with a prior history of GDM had significantly elevated levels of FPG (ß = 0.40, 95% CI: 0.18 to 0.62, PFDR < 0.001), HbA1c (ß = 0.22, 95% CI: 0.09 to 0.34, PFDR = 0.009), TyG (ß = 0.22, 95% CI: 0.07 to 0.37, PFDR = 0.024) at 6 years postpartum, and the association between GDM and SCR (ß = 2.43, 95% CI: 0.02 to 4.85, PFDR = 0.144) reached nominal significance level. GDM history was associated with a decreased level of third-trimester IL-17 A (ß = -0.58, 95% CI: -0.99 to -0.18, PFDR = 0.035). No significant association between third-trimester inflammatory factors and 6-year postpartum metabolic indicators was observed. And no mediating or moderating effect of third-trimester inflammatory factors was observed in those associations. CONCLUSION: A prior history of GDM was significantly associated with elevated FPG, HbA1c, and TyG in women at 6 years postpartum, whereas third-trimester inflammatory factors had no role in mediating or moderating these associations.

The impact of maternal anxiety during pregnancy on children's eczema and allergic rhinitis: The Ma'anshan birth cohort study.

OBJECTIVE: The objective of this study was to investigate the associations between maternal exposure to anxiety during pregnancy and the susceptibility of offspring to eczema and allergic rhinitis and the possibility of sensitivity periods and cumulative effects. METHODS: The study's sample consisted of 3160 mother-child pairs from the Ma'anshan Birth Cohort Study. Maternal anxiety was repeatedly measured in the 1st, 2nd, and 3rd trimesters of pregnancy using the Chinese version of the Pregnancy-Related Anxiety Scale. Information regarding children's eczema and allergic rhinitis diagnoses was collected through parental reports at 12, 24, 36 and 48 months of age. Binary logistic regression models were used for statistical analysis and corrected for multiple comparisons using the false discovery rate (FDR) method. RESULTS: Children whose mothers experienced anxiety throughout pregnancy had the highest odds of developing total eczema (aOR 1.45, 95% CI 1.02-2.07) and total allergic rhinitis (aOR 1.67, 95% CI 1.17-2.37) between the ages of 6 and 48 months. The higher the trajectory of the maternal anxiety scores throughout pregnancy, the higher the odds of total eczema (aOR 1.65, 95% CI 1.14-2.40) and allergic rhinitis (aOR 1.84, 95% CI 1.28-2.66) in their offspring. The association between maternal anxiety and children's eczema was mainly concentrated in the first 24 months, whereas the association with allergic rhinitis was mainly concentrated in the 36-48 months. CONCLUSION: Maternal anxiety during any trimester of pregnancy, especially with a consistently high trajectory of anxiety scores, was associated with higher odds of children's eczema and allergic rhinitis.

Association of preschool children behavior and emotional problems with the parenting behavior of both parents.

BACKGROUND: Parental behaviors are key in shaping children's psychological and behavioral development, crucial for early identification and prevention of mental health issues, reducing psychological trauma in childhood. AIM: To investigate the relationship between parenting behaviors and behavioral and emotional issues in preschool children. METHODS: From October 2017 to May 2018, 7 kindergartens in Ma'anshan City were selected to conduct a parent self-filled questionnaire - Health Development Survey of Preschool Children. Children's Strength and Difficulties Questionnaire (Parent Version) was applied to measures the children's behavioral and emotional performance. Parenting behavior was evaluated using the Parental Behavior Inventory. Binomial logistic regression model was used to analyze the association between the detection rate of preschool children's behavior and emotional problems and their parenting behaviors. RESULTS: High level of parental support/participation was negatively correlated with conduct problems, abnormal hyperactivity, abnormal total difficulty scores and abnormal prosocial behavior problems. High level of maternal support/participation was negatively correlated with abnormal emotional symptoms and abnormal peer interaction in children. High level of parental hostility/coercion was positively correlated with abnormal emotional symptoms, abnormal conduct problems, abnormal hyperactivity, abnormal peer interaction, and abnormal total difficulty scores in children (all P < 0.05). Moreover, paternal parenting behaviors had similarly effects on behavior and emotional problems of preschool children compared with maternal parenting behaviors (all P > 0.05), after calculating ratio of odds ratio values. CONCLUSION: Our study found that parenting behaviors are associated with behavioral and emotional issues in preschool children. Overall, the more supportive or involved the parents are, the fewer behavioral and emotional problems the children experience; conversely, the more hostile or controlling the parents are, the more behavioral and emotional problems the children face. Moreover, the impact of fathers' parenting behaviors on preschool children's behavior and emotions is no less significant than that of mothers' parenting behaviors.

Correlation Between Maternal Anxiety During Mid-Pregnancy and Subsequent Infant Sleep Issues: A Cross-Sectional Study from 2015 to 2016.

Purpose: To explore the correlation between maternal anxiety during mid-pregnancy and infant sleep issues based on the anxiety status of mothers in mid-pregnancy. Patients and Methods: A cohort of 2122 primigravida women from Ma'anshan City, Anhui Province, was followed from pregnancy until 6 months postpartum. The study analyzed the impact of maternal anxiety on infant sleep patterns, including primary caregivers, encompassing insufficient sleep duration, frequent nocturnal awakenings, prolonged nocturnal awakening durations, and elongated sleep latency. Results: A total of 1891 mother-infant pairs were included in this analysis. After adjusting for confounding factors, a positive correlation was found between maternal anxiety during mid-pregnancy and insufficient sleep duration (OR=1.69, 95% CI:1.13-2.52), and elongated sleep latency (OR=2.26, 95% CI:1.61-3.18). Conclusion: Maternal anxiety during mid-pregnancy is associated with sleep issues in infants. Addressing maternal mental health during pregnancy may enhance sleep quality for mothers and infants, promoting overall maternal-infant health.

The associations of gestational weight gain and midpregnancy lipid levels with placental size and placental-to-birth weight ratio: findings from a chinese birth cohort study.

BACKGROUND: The placenta serves as the sole maternal organ responsible for transmitting nutrients to the fetus, playing a crucial role in supporting standard fetal growth and development. To date, only a small number of studies have investigated the impact of maternal gestational weight gain and lipid concentrations on placental development. This study aimed to explore the influence of weight gain during pregnancy and lipid levels in the second trimester on placental weight, volume, and the placental weight ratio. METHODS: This birth cohort study encompassed 1,358 mother-child pairs. Placental data for each participant was gathered immediately post-delivery, and the study incorporated data on gestational weight gain throughout pregnancy and lipid profiles from the mid-trimester. A linear regression model was employed to assess the correlations between gestational weight gain, mid-trimester lipid levels, and metrics such as placental weight, placental volume, and the placental-to-birth weight ratio (PFR). RESULTS: In the study groups of pre-pregnancy underweight, normal weight, and overweight, the placental weight increased by 4.93 g (95% CI: 1.04-8.81), 2.52 g (95% CI: 1.04-3.99), and 3.30 g (95% CI: 0.38-6.22) per 1 kg of gestational weight gain, respectively. Within the pre-pregnancy underweight and normal weight groups, the placental volume increased by 6.79 cm^3 (95% CI: 3.43-10.15) and 2.85 cm^3 (95% CI: 1.31-4.39) per 1 kg of gestational weight gain, respectively. Additionally, placental weight exhibited a positive correlation with triglyceride (TG) levels (ß = 9.81, 95% CI: 3.28-16.34) and a negative correlation with high-density lipoprotein (HDL-C) levels (ß = - 46.30, 95% CI: - 69.49 to - 23.11). Placental volume also showed a positive association with TG levels (ß = 14.54, 95% CI: 7.69-21.39). Conversely, PFR demonstrated a negative correlation with increasing HDL-C levels (ß = - 0.89, 95% CI: - 1.50 to - 0.27). CONCLUSIONS: Gestational weight gain was significantly correlated with both placental weight and volume. This association was especially pronounced in women who, prior to pregnancy, were underweight or of normal weight. Additionally, TG and HDL-C levels during the mid-trimester were linked to placental development.

Joint effects of prenatal exposure to air pollution and pregnancy-related anxiety on birth weight: A prospective birth cohort study in Ma'anshan, China.

BACKGROUND: A growing number of studies have shown that prenatal exposure to chemical and non-chemical stressors has effects on fetal growth. The co-exposure of both better reflects real-life exposure patterns. However, no studies have included air pollutants and pregnancy-related anxiety (PrA) as mixtures in the analysis. METHOD: Using the birth cohort study method, 576 mother-child pairs were included in the Ma'anshan Maternal and Child Health Hospital. Evaluate the exposure levels of six air pollutants during pregnancy using inverse distance weighting (IDW) based on the pregnant woman's residential address and air pollution data from monitoring stations. Prenatal anxiety levels were assessed using the PrA Questionnaire. Generalized linear regression (GLR), quantile g-computation (QgC) and bayesian kernel machine regression (BKMR) were used to assess the independent or combined effects of air pollutants and PrA on birth weight for gestational age z-score (BWz). RESULT: The results of GLR indicate that the correlation between the six air pollutants and PrA with BWz varies depending on the different stages of pregnancy and pollutants. The QgC shows that during trimester 1, when air pollutants and PrA are considered as a whole exposure, an increase of one quartile is significantly negatively correlated with BWz. The BKMR similarly indicates that during trimester 1, the combined exposure of air pollutants and PrA is moderately correlated with a decrease in BWz. CONCLUSION: Using the method of analyzing mixed exposures, we found that during pregnancy, the combined exposure of air pollutants and PrA, particularly during trimester 1, is associated with BWz decrease. This supports the view that prenatal exposure to chemical and non-chemical stressors has an impact on fetal growth.

Early sleep duration trajectories and children's cognitive development: a prospective cohort study.

We aimed to investigate the association between sleep duration trajectories and cognitive performance in preschool-aged Chinese children. We included 2131 children from the Ma'anshan birth cohort (MABC) study. Sleep duration trajectories from 6 to 48 months of age were determined using the group-based trajectory modeling (GBTM). Children's intellectual development was assessed using the Wechsler Preschool and Primary Scale of Intelligence. Compared to those with a medium total sleep duration trajectory, children with a short total sleep duration trajectory had poorer cognitive performance on the Visual Spatial Index (VSI) (ß = -3.65; 95% CI = -6.77 to -0.53), which was associated with an increased risk of a low full-scale intelligence quotient (FSIQ) (OR = 1.60; 95% CI = 1.02 to 2.51). The short total sleep duration trajectory was associated with a low VSI compared with both the medium total sleep duration trajectory and the long total sleep duration trajectory. Compared to children with normal nighttime sleep duration and normal daytime sleep duration trajectories, children with short nighttime sleep and long daytime sleep duration trajectories, normal nighttime sleep and long daytime sleep duration trajectories, and short nighttime sleep and normal daytime sleep duration trajectories all had lower cognitive performance. The restricted cubic spline (RCS) also showed that children with and appropriate total sleep duration, an adequate nighttime sleep duration, and a moderate daytime sleep duration had higher FSIQ. CONCLUSIONS: The results of this study emphasize that a medium total sleep duration, adequate sleep at nighttime, and appropriate sleep in the daytime appear to be more beneficial for children's cognitive development. WHAT IS KNOWN: • Sleep duration in infancy is strongly associated with neurocognitive development. WHAT IS NEW: • Medium and long total sleep duration trajectories are beneficial for children's cognitive performance compared to the short total sleep duration trajectory. • A medium total sleep duration, adequate sleep at nighttime and appropriate sleep in the daytime appear to be more beneficial for children's cognitive development.

The effects of gestational diabetes mellitus on fetal growth: is it different for low-risk and medium-high-risk pregnant women?

BACKGROUND: It has been suggested that gestational diabetes mellitus (GDM) alters the growth trajectory of a fetus and increases the risk of abnormal birth weight. In spite of this, there is still a significant debate regarding the mode and optimal timing of diagnosing this condition. Our aim was to determine fetal growth velocity and birth biometry in pregnant women with GDM at varying risk levels. METHODS: We conducted a cohort study involving 1023 pregnant women at a maternity hospital in Ma'anshan, China. All women completed an oral glucose tolerance test at 24-28 weeks' gestation. We measured fetal head circumference (HC), femoral length (FL), abdominal circumference (AC), biparietal diameter (BPD), and estimate fetal weight (EFW) by ultrasound at 17, 24, 31, and 35 weeks' gestation, respectively. RESULTS: Overall, 5115 ultrasound scans were performed. Among both low-risk and medium-high-risk pregnant women at 17-24 weeks' gestation, GDM exposure was associated with an increase in fetal growth velocity. Neonates born to women with GDM at medium-high risk had significantly larger birth weights than those born to women without GDM, while this was not observed in women at low risk. CONCLUSION: In medium-high-risk pregnant women, exposure to GDM has a greater effect on the fetus, leading to abnormal fetal growth velocity that lasts beyond week 24. It is evident from our results that the effects of GDM on fetal growth differ between medium-high-risk pregnant women and low-risk pregnant women, and therefore a different screening program based on the risk factor for GDM is warranted.

The impact of household fuel usage on adverse pregnancy outcomes in rural Ma'anshan City, Anhui Province: a birth cohort study.

The combustion of cooking fuels generates detrimental gases significantly impacting human health, particularly for vulnerable populations like expectant mothers. Prenatal exposure of such hazardous emissions raises the probability of adverse pregnancy outcomes, including preterm birth (PTB) and low birth weight (LBW). Our research aims to explore the association between cooking fuel utilization and adverse birth outcomes in rural Ma'anshan, Anhui Province. A prospective cohort study was executed, employing the Maternal and Infant Health Assessment questionnaire to classify fuels into clean (natural gas, electricity) and polluting energy sources (coal, coal gas, firewood). Multivariate logistic regression models were conducted to evaluate the association between fuel consumption and postpartum maternal and infant outcomes. Among the 442 surveyed pregnant women, 38.2% (N=169) utilized polluting fuels. After adjusting for covariates such as age and BMI, the relative risks of preterm birth, low birth weight, and postpartum hemorrhage in the polluting fuel group compared to the clean fuel group were OR: 3.27, 95% CI: 1.34, 8.00; OR: 3.50, 95% CI: 1.12, 10.90; and OR: 3.18, 95% CI: 1.06, 9.46, respectively. These results indicate that the usage of polluting fuels during pregnancy may heighten the risk of adverse birth outcomes. Consequently, additional research is advised to mitigate the harmful emissions generated by cooking fuels and advocate for clean energy adoption, enhancing maternal and infant well-being.

Trimester-specific effects of maternal exposure to single and mixed metals on cord serum inflammatory cytokines levels: A prospective birth cohort study.

BACKGROUND: Cord blood inflammatory cytokines are vital in early-life programming. An increasing number of studies concern the effect of maternal exposure to different metal elements during pregnancy on inflammatory cytokines, but limited studies have explored the association between maternal exposure to mixed metals and cord blood inflammatory cytokine levels. METHODS: We measured serum concentrations of vanadium (V), copper (Cu), arsenic (As), cadmium (Cd), and barium (Ba) in the first, second, and third trimesters and eight cord serum inflammatory cytokines (IFN-γ, IL-1ß, IL-6, IL-8, IL-10, IL-12p70, IL-17A, and TNF-α) in 1436 mother-child dyads from the Ma'anshan Birth Cohort. Generalized linear models and Bayesian kernel machine regression (BKMR) were performed to assess the association of single and mixed metal exposure during each trimester with cord serum inflammatory cytokine levels, respectively. RESULTS: Regarding metal exposure in the first trimester, V was positively associated with TNF-α (ß = 0.33, 95 % CI: 0.13, 0.53); Cu was positively associated with IL-8 (ß = 0.23, 95 % CI: 0.07, 0.39); Ba was positively associated with IFN-γ and IL-6; As was negatively associated with IFN-γ and IL-17A; and Cd was negatively associated with IFN-γ, IL-1ß, IL-12p70, IL-17A, and TNF-α. BKMR revealed that exposure to metal mixtures in the first trimester was positively associated with IL-8 and TNF-α but negatively associated with IL-17A. Moreover, V contributed the most to these associations. Interaction effects were observed between Cd and As and between Cd and Cu with IL-8, and between Cd and V with IL-17A. Among males, As decreased inflammatory cytokines; among females, Cu increased inflammatory cytokine levels, whereas Cd decreased inflammatory cytokine concentrations. CONCLUSIONS: Maternal exposure to metal mixtures in the first trimester interfered with cord serum inflammatory cytokine levels. The associations of maternal exposure to As, Cu and Cd with inflammatory cytokines showed sex differences. Further studies are warranted to support the findings and explore the mechanism of the susceptibility window and sex-specific disparity.

The association between early pregnancy exposure to green space and maternal glucolipid metabolism disorders: evaluation of the mediating role of serum 25-hydroxyvitamin D.

Green space and 25-hydroxyvitamin D (25(OH)D) can affect maternal and infant health, but limited studies have examined their effects on disorders of maternal glucolipid metabolism. We aimed to explore the interaction between green space, maternal serum 25(OH)D, and disorders of glucolipid metabolism in early pregnancy. A total of 2551 pregnant women were recruited from the Maanshan Maternal and Child Health Hospital birth cohort in China between 2020 and 2022. We calculated average residential greenness during early pregnancy using 250 m normalized difference vegetation index (NDVI) from satellites. Serum biomarkers (25(OH)D, total cholesterol (TC), triglycerides (TG), high-density lipoprotein-cholesterol(HDL-C), low-density lipoprotein cholesterol (LDL-C), apolipoprotein A1(ApoA1), and apolipoprotein B(ApoB)) were measured. Associations between the factors were analyzed using multiple linear regression, mediation analysis, and stratified analysis. After adjusting for potential confounders, green space exposure associated with decreased TG (- 7.8%; 95% confidence interval (CI): - 12.8, - 2.9), TC (- 7.0%; 95% CI: - 11.4, - 2.7), and LDL-C (- 8.4%; 95% CI: - 12.9, - 3.9), ApoB (- 2.0%; 95% CI: - 3.0, - 1.0) and increased HDL-C (2.7%; 95% CI: 1.5, 3.8) and ApoA1 (5.1%; 95% CI: 3.9, 6.3) for each IQR increase in NDVI. A comparable link was found between maternal serum 25(OH)D and indicators of glucolipid metabolism (P < 0.05). In addition, mediation analysis showed that the association between green space exposure and maternal glucolipid metabolic index was mediated by serum 25(OH)D at 6.37%. In stratified analyses, a considerable association between 25(OH)D and glucolipid metabolic index (except TG) was observed only at higher green space exposures. This study confirms that high levels of green space exposure in early pregnancy and vitamin D are associated with a reduced risk of glucolipid metabolism disorders and suggests that green space may favor glucolipid metabolism by increasing vitamin D levels, particularly at high NDVI values.

The Possible Effects of Breastfeeding on Infant Development at 3 Months: A Case-Control Study.

Objective: To examine the influence of exclusive breastfeeding on infant development among 3-month-old infants in a Chinese population. Methods: Mothers and their 3-month-old infants were recruited from four maternal and child health hospitals from April 2018 to March 2019. Based on the infants' feeding patterns, the mother-infant dyads were divided into two groups: exclusive breastfeeding and formula feeding groups. Infant development was evaluated using the Chinese version of the Ages and Stages Questionnaires, 3rd edition (ASQ-C), and maternal depression, parenting confidence, and infant temperament were also assessed using the relevant scales/questionnaires. Multivariate logistic regression analysis was conducted to explore the effects of feeding patterns on infant development at 3 months. Results: The data from 417 mother-infant dyads were analyzed. For the breastfeeding group and formula feeding group, the risk of developmental delay measured by the ASQ-C was 4.1% (10/244) and 9.3% (16/173) respectively for the communication domain; 5.7% (14/244) and 8.1% (14/173) for problem-solving domain and 6.2% (15/244) and 12.1% (21/173) for personal-social domain, respectively. Compared with exclusive breastfeeding, formula feeding was a risk factor for delayed development of communication (adjusted odd ratio [aOR] = 2.60, 95% confidence interval [CI] = 1.42-4.75) problem-solving (aOR = 1.91, 95% CI = 1.06-3.45), and personal-social skills (aOR = 1.96, 95% CI = 1.12-3.42). Conclusions: Exclusive breastfeeding is important for infant communication, problem solving, and social interaction at the age of 3 months. Formula-fed infants may be at a higher risk of developmental delay than exclusively breast-fed infants. It is necessary to encourage mothers to establish and continuous breastfeeding.

Housing type and myopia: the mediating role of parental myopia.

BACKGROUND: Myopia has become a significant global public health concern, and is highly prevalent worldwide especially in Asian countries. It is associated with genetic factors as well as socioeconomic status; however, the underlying cause for school myopia has not been established. This study evaluates the impact of living environment on school myopia in Chinese school-aged children. METHODS: A large cross-sectional sample of area- and ethnicity-matched school children; a total of 43, 771 children from 12 cities participated in this study. The presence of myopia was self-reported and potential risk factors were determined by questionnaires. RESULTS: The self-reported prevalence of myopia in Chinese children was 31.8 % (n = 13, 928). In multiple logistic regression analysis, higer risk of myopia among school-aged children was significantly positively associated with both parental myopia (OR = 3.57; 95 % CI: 3.26-3.90), living in 1-3 floor (OR = 1.28; 95 % CI: 2.57-3.15), 4-6 floor (OR = 1.84; 95 % CI: 1.73-1.95) and 7 floor or more (OR = 2.02; 95 % CI: 1.88-2.16). Particularly, housing type was independently associated with myopia after stratified by parental myopia. An increasing prevalence of myopia was found with increasing floor of housing type in each outdoor time group. CONCLUSIONS: Housing type was independently associated with myopia, after stratified by parental myopia. Flat room, lower living floor and more outdoor time may be protective factors for myopia among school-aged children in mainland China.

[Analysis on the time of sunshine exposure among Chinese primary and middle school students in 12 provinces].

OBJECTIVE: To investigate the characteristics on the time of sunshine exposure in Chinese primary and middle school students. METHODS: A total of 43 771 primary and middle school students were randomly selected from 12 provinces in China. A self-reported questionnaire was used to understand their time of sunshine exposure on weekdays and weekends as well as related family information and behaviors.χ(2) test was used to compare the hours of sunshine exposure among different groups. Multivariate logistic regression analysis was conducted to identify the influencing factors. RESULTS: Results from the current survey indicated that the average time of sunshine exposure on weekdays and weekends were 2.49 and 3.22 hours, respectively. On weekdays, proportions of students with time of sunshine exposure ≤2 h/d or >2 h/d were 60.81% and 39.19%, respectively. On weekends, the proportions became 44.05% and 55.95%, respectively. On weekdays, the time of sunshine exposure as ≤2 h/d was significantly different among factors as sex, urban or rural area, residential area, self-rating academic performance, type of housing or ways of commuting to school. On weekends, the time of sunshine exposure ≤2 h/d were significantly different among sex, residential areas, self-rating academic performance, type of housing and ways of commuting to school. Data from the multivariate logistic regression analysis showed that the limited sunshine exposure was significantly associated with factors as: type of primary schools, being girls, students living in the urban area or living in central or western areas, with normal or better academic performances, living in a flat apartment and the time spent on watching video program >2 h/d both on weekdays and weekends. CONCLUSION: The time of sunshine exposure seemed not enough among school students and significant differences were seen among different groups.

Effect of outdoor activity on myopia onset and progression in school-aged children in northeast China: the Sujiatun Eye Care Study.

BACKGROUND: Due to its high prevalence and associated sight-threatening pathologies, myopia has emerged as a major health issue in East Asia. The purpose was to test the impact on myopia development of a school-based intervention program aimed at increasing the time student spent outdoors. METHODS: A total of 3051 students of two primary (grades 1-5, aged 6-11) and two junior high schools (grades 7-8, aged 12-14) in both urban and rural Northeast China were enrolled. The intervention group (n = 1735) unlike the control group (n = 1316) was allowed two additional 20-min recess programs outside the classroom. A detailed questionnaire was administered to parents and children. Uncorrected visual acuity (UCVA) was measured using an E Standard Logarithm Vision Acuity Chart (GB11533-2011) at baseline, 6-month and 1-year intervals. A random subsample (n = 391) participated in the clinic visits and underwent cycloplegia at the beginning and after 1 year. RESULTS: The mean UCVA for the entire intervention group was significantly better than the entire control group after 1 year (P < 0.001). In the subgroup study, new onset of myopia and changes in refractive error towards myopia were direction during the study period was significantly lower in the intervention group than in the control group (3.70 % vs. 8.50 %, P = 0.048; -0.10 ± 0.65 D/year vs. -0.27 ± 0.52 D/year, P = 0.005). Changes in axial length and IOP were also significantly lower following the intervention group (0.16 ± 0.30 mm/year vs. 0.21 ± 0.21 mm/year, P = 0.034; -0.05 ± 2.78 mmHg/year vs. 0.67 ± 2.21 mmHg/year, P = 0.006). CONCLUSIONS: Increasing outdoor activities prevented myopia onset and development, as well as axial growth and elevated IOP in children. TRIAL REGISTRATION: Current controlled trials NCT02271373.

[Association between elevated light levels in classrooms and change in vision acuity among elementary and secondary students].

OBJECTIVES: To explore the association between elevated light levels in classrooms and change in vision acuity among elementary and secondary students. METHODS: A total of 4 elementary (grade 1-5) and secondary (grade 7-8) schools in urban and rural areas in Sujiatun, Shenyang, China were selected by cluster sampling as experimental schools, and lighting systems have been rebuilt to improve the ambient light levels in 56 classrooms in November 2012. The control schools were chosen for the comparable academic burden and adjacent location to experimental schools, 4 schools in all. Cluster sampling of all students in the selected schools as the subjects was carried out. A total of 2 092 students were chosen as experimental group and 1 595 students were in the control group. The luxmeter was used to measure illuminance of classrooms in two groups at baseline, and intervention for 1 month, respectively.Students in both groups were underwent 3 times for vision acuity examination by standard logarithmic visual acuity chart at baseline, intervention for 6 month and intervention for 1 year, respectively. The light levels of desk and blackboard in two groups were compared by Wilcoxon test. Multivariate analysis of covariance with repeated measures was performed to assess three vision acuity results between groups. RESULTS: After intervention, the average illuminance of desk (117.5 vs 532.5 lx, Z = -5.38, P < 0.001) and blackboard (75.6 vs 423.5 lx, Z = -5.38, P < 0.001) and uniformity of desk (Z = -4.28, P < 0.001) with new lighting were improved significantly than that with old lighting, however the uniformity of blackboard was lower than baseline significantly (0.64 vs 0.70, Z = -2.34, P = 0.019). The average scores of vision acuity in students at baseline, intervention for 6 month and intervention for 1 year were 4.87 ± 0.23, 4.84 ± 0.25 and 4.85 ± 0.23 in experimental group, and 4.88 ± 0.22, 4.84 ± 0.25 and 4.81 ± 0.27 in control group, respectively. The significant differences between groups were found and F values were 1.41, 0.13, 19.99, P values were 0.235,0.724, <0.001. At last the average vision acuity in experimental group were significantly better than that in control group either among elementary (4.90 ± 0.20) vs (4.87 ± 0.21) score, F = 13.61, P < 0.001 or secondary students (4.73 ± 0.28) vs (4.68 ± 0.32) score, F = 14.25, P < 0.001. CONCLUSIONS: Visual acuity loss could be decreased in students with elevated light levels which may slow the response to myopiagenic stimuli for eyes, therefore the ambient light levels of blackboard and desk in classroom should be improved.

Incidence and risk factors of bacterial vaginosis among pregnant women: a prospective study in Maanshan city, Anhui Province, China.

AIM: The aim of this study was to identify the incidence and risk factors of bacterial vaginosis among pregnant women. MATERIAL AND METHODS: Prospective data from a cohort of 668 pregnant women were used to identify potential risk factors for bacterial vaginosis during pregnancy by Cox proportional hazards regression. RESULTS: A total of 204 incident cases of bacterial vaginosis were diagnosed in 274.8 woman-years of follow-up. The bacterial vaginosis incidence rate was 0.74 per 1 woman-year and median prevalence during follow-up was 15.6%. In the adjusted model, changing underwear nearly everyday, miscarriage history, urinary tract infection during follow-up, husbands' education level, and concurrent trichomoniasis and candidiasis remained significantly associated with bacterial vaginosis (adjusted hazard ratio and 95% confidence interval were 1.87 [1.26-2.77]; 2.96 [1.96-4.47]; 2.41 [1.05-5.49]; 0.50 [0.32-0.77]; 1.82 [1.02-3.25]; 1.88 [1.30-2.70], respectively). CONCLUSION: Bacterial vaginosis during pregnancy can be affected by many factors, and some are indirectly acting factors. Further prospective studies that include a larger sample size and more information on the development of bacterial vaginosis are needed.

Elevated light levels in schools have a protective effect on myopia.

PURPOSE: To determine whether elevated light levels in classrooms in rural areas can protect school-age children from myopia onset or myopia progression. METHODS: A total of 317 subjects from 1713 eligible students aged six to 14 in four schools located in northeast China participated in the study. Students received a comprehensive eye examination including cycloplegic refraction and ocular biometry, which included axial length (AL), anterior chamber depth (ACD), and corneal curvature (CC) measurement, and completed a questionnaire. The intervention arm included 178 students in two schools with rebuilt elevated lighting systems and the control arm included 139 students in which lighting systems were unchanged. Results for the two arms were compared with a Wilcoxon rank sum test, a chi-squared test or a t-test, as appropriate. Factors that might help explain any differences were explored with multivariate linear regression analysis. RESULTS: The median average illuminance of blackboards and desks and uniformity of desk lighting were significantly improved, however, the uniformity of blackboard lighting declined after intervention. At baseline, the mean refraction, AL, CC, ACD and myopia prevalence between the two arms were not significantly different. After 1 year, compared with the control arm the intervention arm had a lower incidence of new myopia onset (4% vs 10%; p = 0.029), a smaller decrease in refractive error among no myopic subjects (-0.25 dioptre [D] vs -0.47 D; p = 0.001), and shorter axial growth for both non-myopic (0.13 vs 0.18 mm; p = 0.023) and myopic subjects (0.20 vs 0.27 mm; p = 0.0001). Multivariate linear regression analysis showed the intervention program, lower hyperopic baseline refraction, lower father's education level, longer time sleeping and less time in screen-viewing activities were associated with less refractive shift in the direction of myopia in non-myopic children. For myopic subjects, myopia progression was significantly associated with family income only. The intervention program and older age had a protective effect on axial growth for both myopic and non-myopic subjects. The father's education level and sleep duration were significantly associated with axial growth in non-myopic children. CONCLUSIONS: Elevated light levels in classrooms have a significant effect on myopia onset, decreases in refraction, and axial growth; if the findings of lighting intervention are reproduced in future studies, the ambient light levels in schools should be improved.

Prevalence and associated factors of induced abortion among rural married women: a cross-sectional survey in Anhui, China.

AIM: This study aims to assess the prevalence of and factors associated with induced abortion among married women in rural areas of Anhui Province, China. MATERIAL AND METHODS: A multistage probability sampling method was used to identify a representative sample of 53,652 married women aged 18-49 years in rural areas of Anhui Province, China. All women were interviewed in the form of a standardized questionnaire. RESULTS: We found that 32.0% (16,800) of these women had had at least one induced abortion: 21.1% (11,090) of women had had one; 7.6% (3976) of women had had two; and 4.1% (1734) of women had had at least three. The number of induced abortions per 100 pregnancies was found to be 22.0. Multivariate analysis showed that education, the age of a woman at her first marriage, number of total births, number of total pregnancies, and contraceptive methods were significant predictors for induced abortion after controlling for women's current age, employment and family yearly income. CONCLUSION: The study shows that the prevalence of induced abortion is still very high among married women in rural China, and highly effective methods of contraception (sterilization, intrauterine device) decrease women's recourse to induced abortion.