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Early life is a critical window period that determines the growth and development of children, but this delicate and complex period is highly susceptible to the disturbance of various exogenous chemicals, which in consequence may lead to short-term or long-term adverse health effects in human beings. The massive use of antibiotics has contributed to widespread exposure in early life, along with the potentially adverse effects on child health, and has caused great concern in public health. This review summarized recent epidemiological studies on the population with early-life antibiotic exposure and associated health outcomes such as growth and development, allergies, and psycho-behavioral problems in children, as well as potential biological mechanisms underlying these associations. Current findings suggested that antibiotic exposure early in life, including pregnancy and infancy, is strongly associated with childhood allergic diseases (e.g., atopic dermatitis and asthma), growth and development (e.g., obesity and birth length), and childhood psycho-behavioral problems (e.g., autism and anxiety). It also suggested that antibiotic exposure may affect individual health through gut microbiota, thyroid function, inflammation factors, mitochondrial function, and epigenetic mechanisms. In the future, more large prospective birth cohorts should be established to determine the levels of internal exposure to different types of antibiotics at multiple time points in early life and to explore their associations with child health outcomes, as well as to further validate relevant mechanisms, aiming to provide high-quality scientific evidence for research on child health associated with environmental exposure in early life.
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In recent years, the effects of air pollutants on the neurodevelopmental disorders in children have received widespread attention. Early life is a critical period of rapid brain development, and exposure to air pollutants during this period may permanently alter brain function. This paper reviewed the epidemiological studies on the association between exposure to air pollutants during early life and children's neurodevelopmental disorders in recent years, with focus on outdoor air pollutants (e.g., PM2.5, PM10, NOx, and CO) and indoor air pollutants (e.g., cooking oil fumes, tobacco and mosquito incense smoke, and formaldehyde from home decoration), and summarized their possible biological mechanisms. Most studies indicate that pollutants in different periods and at different levels of exposure during early life can negatively affect children's neurodevelopment and that there may be a dose-response relationship between certain air pollutants and children's neurodevelopment. Current research on the effects of indoor air pollutants on children's neurodevelopment focus on exposure to tobacco smoke, while other indoor air pollutants such as cooking oil fumes and organic compounds produced by interior decorative materials are less well reported and their underlying biological mechanisms are not yet clear. Further epidemiological studies, animal and cellular experiments are needed to provide evidence for the neurodevelopmental toxicity of air pollutant exposure in the future, aiming to provide a theoretical basis for environmental eugenics and promote healthy development of children.
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Cadmium exposure during pregnancy is a non-negligible public health problem which may increase the risk of shortened telomere length in newborns and cardiovascular metabolic health damage in children, and has attracted attention from many researchers in recent years. This article reviewed recent studies both domestically and internationally on the associations among cadmium exposure during pregnancy, shortened telomere length in newborns, and cardiovascular metabolic abnormalities in children, and briefly outlined possible mechanisms of shortened telomere length in newborns by cadmium exposure during pregnancy. Current research results showed that cadmium exposure during pregnancy is related to shortened telomere length in newborns and cardiovascular metabolic abnormalities in children, and shortened telomere length in newborns is also related to cardiovascular metabolic abnormalities in children. It suggested that telomere length in newborns may be a biomarker reflecting cardiovascular metabolic abnormalities in children caused by cadmium exposure during pregnancy. In addition, the current potential mechanisms of cadmium exposure during pregnancy accelerating neonatal telomere length shortening include inflammatory reaction, mitochondrial dysfunction, antioxidant consumption/antioxidant enzyme inactivation, and DNA methylation, and these biological mechanisms are associated with cardiovascular metabolic abnormalities through certain factors, such as obesity, elevated blood pressure, impaired fasting blood glucose, and dyslipidemia in children, suggesting that cardiovascular metabolic abnormalities in children may be programmed in early life, but there are still few relevant studies. In the future, research should be conducted on the association among cadmium exposure during pregnancy, telomere length, and offspring cardiovascular metabolism, as well as possible mediating efficacy and related biological mechanisms of telomere length, aiming to provide early-life biological information for the prevention of cardiovascular and metabolic diseases.
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Objective:To investigate the effects of maternal subclinical hypothyroidism (SCH) on preschoolers′ behavioral problems.Methods:Based on the Ma′ anshan Birth Cohort, pregnant women who had their first antenatal checkup in Maternal and Child Health Center in Ma′ anshan were recruited from May 2013 to September 2014. Data on demographic, obstetric information, and maternal exposure were collected. Women′s fasting venous blood in the first, second, and third trimesters of pregnancy was collected. The levels of thyroid hormones [thyrotropin (TSH), free thyroxine (FT 4)] and thyroid autoantibodies [thyroid peroxidase antibody (TPOAb), thyroglobulin antibody (TgAb)] in maternal blood were retrospectively detected by electrochemiluminescence immunoassay. Preschoolers′ behavioral problems were assessed by Achenbach Child Behavior Checklist (CBCL/1.5-5). Poisson regression models were adopted to examine the effect of maternal SCH on preschoolers′ internalizing and externalizing problems and the critical period. Results:In this study, the reference of maternal thyroid indexes was established (between 2.5 th and 97.5 th percentile). The reference of TSH in the first, second, and third trimester of pregnancy was 0.04-4.90 μIU/mL, 0.75-6.08 μIU/mL, and 0.58-5.59 μIU/mL respectively; and the reference of FT 4 was 13.19-23.27 pmol/L, 9.14-15.32 pmol/L, and 9.53-17.45 pmol/L respectively. In the first, second, and third trimester of pregnancy, the prevalence of SCH was found to be 2.0% (25/1 224), 1.6% (19/1 218), and 1.7% (21/1 220), respectively. After adjusting for confounding factors, maternal SCH in the first trimester was associated with the risk of anxiety and depression in preschool children ( OR=3.06, 95% CI 1.05-8.98). Maternal SCH in the second trimester was found to be associated with the risk of overreaction in preschool children ( OR=2.65, 95% CI 1.13-6.21). Conclusions:The establishment of thyroid hormones reference range for pregnant women in Ma′ anshan area is beneficial to the screening, diagnosis, and treatment of thyroid diseases during pregnancy in this area. Maternal SCH during pregnancy is associated with increased risk of behavioral problems in preschool children. In the first trimester, maternal SCH was associated with preschoolers′ anxiety and depression, and in the second trimester, maternal SCH was associated with preschoolers′ emotional reactivity.
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Objective:To explore the protective effects of breastfeeding on behavioral problems at 4 years in children born to mothers with gestational diabetes mellitus (GDM).Methods:Based on the Ma' anshan Birth Cohort (MABC) study, 305 GDM women and their children were recruited in this study from Ma' anshan Maternal and Child Health Care Hospital from May 2013 to September 2014. Total breastfeeding duration was followed up at 42 d, 3, 6, 12, and 18 months postpartum as well as the breastfeeding intensity within 6 months. All the subjects were divided into breastfeeding group ( n=256, including exclusive breastfeeding and mixed feeding) or bottle feeding group ( n=49). Internalizing and externalizing behavioral problems at age 4 were assessed using Achenbach Child Behavior Checklist (CBCL/1.5~5) and their association with breastfeeding were analyzed using robust Poisson regression. Controlling false discovery rate was applied for multiple test correction. Results:Compared with bottle feeding, breastfeeding was a protective factor for depression in children ( RR=0.23, 95% CI: 0.05-0.98, q=0.048) when the duration was 4-5 months; for somatic complaints ( RR=0.36, 95% CI: 0.14-0.95, q=0.047) and anxiety ( RR=0.19, 95% CI: 0.06-0.62, q=0.010) with a breastfeeding duration of 6-11 months; and for depression ( RR=0.46, 95% CI: 0.25-0.83, q=0.039) and anxiety ( RR=0.12, 95% CI: 0.03-0.49, q=0.006) with a breastfeeding duration of 12 months and above. Compared with bottle feeding within 6 months, mixed feeding had a protective effect on somatic complaints ( RR=0.29, 95% CI: 0.13-0.64, q=0.026) and anxiety ( RR=0.18, 95% CI:0.07-0.52, q=0.002). Conclusions:The findings suggested that breastfeeding had a protective effect on behavioral problems at age 4 in children exposed to GDM. Women with GDM should be encouraged to breastfeed.
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The International Agency for Research on Cancer (IARC) defines shift work as any arrangement of daily working hours other than the standard daylight hours (typically 7:00/8:00 am–5:00/6:00 pm). To meet the needs of rapid socioeconomic development, shift work is becoming more and more common. The impact of shift work, especially night shift work, on human health cannot be ignored. Female's health is not only important to the well-being of themselves, but also has a far-reaching impact on their children and even their entire family. Increasing epidemiological studies have focused on the effects of night shift work on female's reproductive health. This article reviewed epidemiological evidence of the associations between night shift work and reproductive outcomes, e.g. menstrual cycle, endometriosis, pregnancy rate, adverse pregnancy outcomes, and ovarian cancer. The potential biological mechanisms connecting night shift work to female reproductive health were also introduced, e.g. melatonin regulation, clock gene regulation, and sex hormone regulation. Through this review, we propose to provide a reference for determining occupational risk factors, conducting subsequent relevant studies, and formulating rational health promotion strategies.
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In recent years, the increasing incidence of perinatal depression has become an important public health problem. In addition to the traditional social demographic factors, biological factors, obstetric factors, etc., the association between air pollution and perinatal depression (PND) has also attracted more and more attention. In this paper, studies on the association between air pollution and PND were reviewed, especially the associations of PND with ambient air pollutants such as PM2.5, PM10, NO2, and O3 as well as indoor air pollutants such as tobacco smoke, and the characteristics and possible biological mechanisms of the influence of different pollutants on PND were summarized. Based on the available studies, various outdoor air pollutants are associated with PND, and some pollutants may exhibit a dose-response relationship with it. As for indoor air pollution, studies only have focused on the impact of tobacco exposure on PND, and as yet, no study has explored the association between other indoor pollutants (e.g. cooking oil smoke and solid fuel) and PND. Current studies indicate that air pollution may act on PND through oxidative stress and neuroendocrine mechanisms, but the exact biological mechanism remains to be further studied. In the future, further studies should be encouraged on the epidemiological associations of other indoor air pollutants with PND and the interactions between other factors and air pollution on PND, and the underlying biological mechanisms, to provide new insights for the prevention of PND from the perspective of environmental health.
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Objective @#To investigate the association between adiposity rebound and metabolic abnormalities in pre- schools.@*Methods @#A prospective cohort study was designed on the basis of the Maanshan birth cohort. Venous blood samples were collected at 5 to 6 years of age to detect metabolic indicators.2022 children aged 0 to 6 years with ≥8 consecutive measurements were enrolled. χ2 test and Logistic regression model were used to analyze the data. @*Results @#The detection rate of abnormal metabolism in preschool children was 16. 9% ,and the risk of meta- bolic abnormalities in preschool children with high BMI level at the AR time point and earlier AR time phase was 2. 59 and 1. 82 times that of the normal group respectively.@*Conclusion @#High AR level and earlier AR phase can increase the prevalence of metabolic abnormalities in preschool children.
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BACKGROUND@#Previous studies have suggested that screen time (ST) has a negative effect on children's emotional and behavioral health, but there are few longitudinal studies that have been conducted with infants and toddlers. This study sought to examine the effect of ST in early childhood on emotional and behavioral problems in children aged 4 years, based on a birth cohort study in China.@*METHODS@#A total of 2492 children aged 4 years were enrolled in this study. The parents and guardians of each child completed a questionnaire that included items eliciting information on children's birth information, socio-demographic information at baseline, and ST at each follow-up. Emotional and behavioral problems were assessed using the Strengths and Difficulties Questionnaire (SDQ) at 4 years of age. Multivariate logistic analysis was used to explore the effects of ST on emotional and behavioral problems.@*RESULTS@#The percentages of children with ST > 0 h/day at age 0.5 years, ST > 2 h/day at age 2.5 years, and ST > 2 h/day at age 4 years were 45.7, 55.5, and 34.5% respectively. The prevalence of emotional and behavioral problems was 10.8%. ST at 6 months was a risk factor for emotional symptoms and hyperactivity at the age of 4 years. ST at age 2.5 years was a risk factor for hyperactivity at the age of 4 years. However, ST at age 4 years was a risk factor for total difficulties, conduct problems, peer problems, hyperactivity, and prosocial behavior.@*CONCLUSIONS@#Higher ST exposure at early childhood is associated with later emotional and behavioral problems. In particular, sustained high ST exposure is a risk factor for behavioral problems. These findings suggested the importance of controlling ST to prevent the occurrence of emotional and behavioral problems in the early years.
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Preescolar , Femenino , Humanos , Masculino , Altruismo , China/epidemiología , Estudios de Cohortes , Emociones , Prevalencia , Problema de Conducta/psicología , Agitación Psicomotora/psicología , Tiempo de PantallaRESUMEN
BACKGROUND@#The 2019 novel coronavirus disease (COVID-19) emerges in China, which spreads rapidly and becomes a public health emergency of international concern. Chinese government has promptly taken quarantine measures to block the transmission of the COVID-19, which may cause deleterious consequences on everyone's behaviors and psychological health. Few studies have examined the associations between behavioral and mental health in different endemic areas. This study aimed to describe screen time (ST), physical activity (PA), and depressive symptoms, as well as their associations among Chinese college students according to different epidemic areas.@*METHODS@#The study design is cross-sectional using online survey, from 4 to 12 February 2020, 14,789 college students accomplished this online study, participants who did not complete the questionnaire were excluded, and finally this study included 11,787 college students from China.@*RESULTS@#The average age of participants was 20.51 ± 1.88 years. 57.1% of the college students were male. In total, 25.9% of college students reported depression symptoms. ST > 4 h/day was positively correlated with depressive symptoms (β = 0.48, 95%CI 0.37-0.59). COVID-19ST > 1 h/day was positively correlated with depressive symptoms (β = 0.54, 95%CI 0.43-0.65), compared with COVID-19ST ≤ 0.5 h/day. Compared with PA ≥ 3 day/week, PA < 3 day/week was positively associated with depression symptoms (β = 0.01, 95%CI 0.008-0.012). Compared with low ST and high PA, there was an interaction association between high ST and low PA on depression (β = 0.31, 95%CI 0.26-0.36). Compared with low COVID-19ST and high PA, there was an interaction association between high COVID-19ST and low PA on depression (β = 0.37, 95%CI 0.32-0.43). There were also current residence areas differences.@*CONCLUSIONS@#Our findings identified that high ST or low PA was positively associated with depressive symptoms independently, and there was also an interactive effect between ST and PA on depressive symptoms.
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Adulto , Femenino , Humanos , Masculino , Adulto Joven , COVID-19/psicología , China/epidemiología , Estudios Transversales , Depresión/etiología , Ejercicio Físico , Salud Mental/estadística & datos numéricos , Tiempo de Pantalla , Estudiantes/psicología , Factores de Tiempo , UniversidadesRESUMEN
ObjectiveThe aim of the study is to analyze the latent class of basic reproduction number (R0) trend of 2019 novel coronavirus disease (COVID-19) in major endemic areas of China. MethodsThe provinces that reported more than 500 cases of COVID-19 till February 18, 2020 were selected as the major endemic area. The Verhulst model was used to fit the growth rate of cumulative confirmed cases. The R0 of COVID-19 was calculated using the parameters of severe acute respiratory syndrome (SARS) and COVID-19, respectively. The latent class of R0 was analyzed using a latent profile analysis model. ResultsThe median R0 calculated from SARS and COVID-19 parameters were 1.84 - 3.18 and 1.74 - 2.91, respectively. The R0 calculated from the SARS parameters was greater than that of calculated from the COVID-19 parameters (Z = -4.782 - -4.623, P < 0.01). Both R0 can be divided into three latent classes. The initial value of R0 in class 1 (Shandong Province, Sichuan Province and Chongqing Municipality) was relatively low and decreases slowly. The initial value of R0 in class 2 (Anhui Province, Hunan Province, Jiangxi Province, Henan Province, Zhejiang Province, Guangdong Province and Jiangsu Province) was relatively high and decreases rapidly. Moreover, the initial value of R0 of class 3 (Hubei Province) was between that of class 1 and class 2, but the higher level of R0 lasts longer and decreases slowly. ConclusionThe results indicated that overall trend of R0 has been falling with the strengthening of Chinas comprehensive prevention and control measures for COVID-19, however, presents regional differences.
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Objective:To investigate the developmental behavior of early term infants at 6 months and its difference from that of complete full-term infants.Methods:A healthy maternal and infant birth cohort in maanshan city, established in Maanshan Maternal and Child Health Hospital from June 2015 to June 2016. Birth outcomes were copied from the hospital electronic medical record system after delivery. The Chinese Ages and Stages Questionnaires was used to assess developmental behavior. The chi-square test and multivariate unconditional logistic regression model were used to analyze the differences in the behavioral development of early and full term infants.Results:The birth rate of early term infants was 24.74% (500/2 021). The detection rates of communication, gross motor, fine motor, problem solving and individual-social areas in early term infants were 2.1%, 3.2%, 6.1%, 6.3% and 2.7%, respectively. The detection rate of problem-solving area in early term infants was significantly higher than that in the full-term infants (6.3% vs. 3.7%, χ 2=5.42, P<0.05). After controlling for confounding factors, compared with full-term infants, the risk of problem-solving area in early infants was significantly increased ( OR=1.65, 95%CI:1.01-2.70, P<0.05). Conclusion:The risk of behavioral retardation in Early term infants is significantly higher than that in full-term infants, and long-term follow-up and appropriate early development promotion interventions are needed to improve their quality of life.
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We used the epidemic data of COVID-19 published on the official website of the municipal health commission in Anhui province. We mapped the spatiotemporal changes of confirmed cases, fitted the epidemic situation by the population growth curve at different stages and took statistical description and analysis of the epidemic situation in Anhui province. It was found that the cumulative incidence of COVID-19 was 156/100 000 by February 18, 2020 and the trend of COVID-19 epidemic declined after February 7, changing from J curve to S curve. The actual number of new cases began to decrease from February 2 to February 4 due to the time of case report and actual onset delayed by 3 to 5 days.
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Objective To assess the association between early adiposity rebound (AR) and indices of obesity and metabolic risk in 5-year-old children. Methods Based on Ma’anshan Birth Cohort Study (MABC), single live births born in Ma'anshan of Anhui province from October 2013 to April 2015 were followed for up to 5 years consecutively. As of August 2019, 720 children with continuous measurements (≥8 times) and metabolic indicators were obtained. Physical examination and laboratory tests were used to obtain information on the birth status, length/height, weight, waist circumference, body composition and metabolic indicators of children. The 2 test, F test, t-test, non-parametric test, general linear model and logistic regression model were used for statistical analysis. Results 43.5% of the children had AR≤4 years. After controlling for gender, it was found that earlier AR was associated with overweight/obesity (OR=2.71, 95%CI: 1.81~4.05), larger waist circumference (OR=1.88, 95%CI: 1.25~2.82), and body fat percentage ≥90th percentile (OR=2.09, 95%CI: 1.26~3.48). In the earlier AR group, the insulin resistance and metabolic score were higher, but the difference was not statistically significant. At 5 years of age, the prevalence of obesity and overweight was 6.0% and 12.8%, respectively. Children with overweight/obesity, larger waist circumference, higher waist-to-weight ratio and body fat percentage ≥ 90th percentile were associated with higher insulin resistance and metabolic score, and all the differences were statistically significant (all P<0.001). Conclusion Earlier AR increased the risk of overweight/obesity, larger waist circumference, and body fat percentage ≥90th percentile at age of 5 years. Each index of the commonly used measures of childhood obesity was closely related with insulin resistance and metabolic risk factors at 5 years old.
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Objective To understand the epidemiological characteristics of the cases of COVID-19 epidemic clusters, and explore the influence of family factors and social factors such as group activities on the spread of the disease. Methods The data of cases of COVID-19 epidemic clusters from 19 January, 2020 to 25 February, 2020 were collected from the official platforms of 36 cities in 6 provinces in China. Descriptive statistical methods, χ 2 test and curve fitting were used to analyze the epidemiological characteristics of the clustered cases. Results By 25 February, 2020, the data of 1 052 cases in 366 epidemic clusters were collected. In these clustered cases, 86.9%(914/1 050) occurred in families. Among the 1 046 cases with gender information, 513 were males (49.0%) and 533 were females (51.0%). The cases were mainly young adults between 18 and 59 years old, accounting for 68.5% (711/1 038). In the 366 epidemic clusters , the clusters in which the first confirmed cases with the history of sojourn in Wuhan or Hubei accounted for 47.0%(172/366). From 19 January to 3 February, 2020, the first confirmed cases with Wuhan or Hubei sojourn history accounted for 66.5%. From 4 to 25 February, the first confirmed cases who had Wuhan or Hubei sojourn history accounted for only 18.2%. The median of interval between the first generation case onset and the second generation case onset was 5 (2-8) days. The median of onset- diagnosis interval of the initial cases was 6 (3-9) days, and the median of onset-diagnosis interval of the secondary cases was 5 (3-8) days. Conclusions Epidemic clusters of COVID-19 were common in many cities outside Wuhan and Hubei. Close contact in family was one of the main causes for the spread of household transmission of the virus. After 4 February, the epidemic clusters were mainly caused by the first generation or second generation cases in local areas, and the time for diagnosis became shorter.
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The 'Healing the Schism: Epidemiology, Medicine, and the Public’s Health’ by professor Kerr L. White’s be published has a history of nearly 30 years. Since then, although scholars have appealed to incorporating public health and clinical medicine education, and breaking down separations between public health and clinical workforce in China, the effect is yet not so obvious. The outbreak of coronavirus disease 2019 (COVID-19) has opened a public class on the treatment, prevention and control of infectious diseases for the Chinese citizens. Consequently, the Chinese people have higher expectations on the modernization of public health governance, and the social atmosphere of incorporating preventive medicine and clinical medical education is establishing. In future, when combating with novel infectious diseases and public health emergencies, the response capacity of public health system and treatment capacity of clinical system will be significantly improved, while the situation on insufficient integration of prevention and treatment is bound to be reversed.
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Objective: To study the dose-response relationship between maternal thyroid hormone levels in the first twenty weeks of pregnancy and the infant physical and neuropsychological development. Methods: In this prospective cohort study, a total of 945 women and their children were included. Maternal serum samples during first half of the pregnancy were collected and analyzed for levels of thyroid hormones by using the electro-chemiluminescence immunoassay. Maternal social demographic information was collected by using the a self-administered questionnaire. Physical measurements of newborns and neuropsychological evaluation of infants were performed by doctors of maternal and child health care. Results: The differences in newborns' birth length and head circumference were significant among the newborns of mothers with different percentiles of maternal serum (thyroid-stimulating hormone, TSH) levels (P<0.05). Newborns with maternal TSH level ≥P(95) or <P(5) had significantly lower birth length and birth head circumference, compared with the newborns with maternal TSH level between P(25)-P(75) (P<0.05). Newborns' birth head circumferences showed an inverted U-shaped association with maternal serum TSH level (Y=33.940+0.003X-0.109X(2), F=4.685, P=0.009). The difference in mental development index (MDI) of the infants at 18-30 months were significant among the infants of mothers with different percentiles of maternal serum TSH level (P<0.05). Infants with maternal TSH level ≥P(90) showed lower MDI (6.39, 95%CI: 2.29-10.49, P=0.002) compared with the infants with maternal TSH level between P(25)-P(75). Infant's MDI at 18- 30 months also showed an inverted U-shaped association with maternal serum TSH level (Y=103.249-1.524X-0.939X(2), F=6.616, P=0.001). Conclusions: Maternal TSH level was associated with newborn's birth length, birth head circumference and infant's MDI at 18-30 months. Newborn's birth head circumference and infant's MDI at 18-30 months showed an inverted U-shaped association with maternal serum TSH-Z score.
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Niño , Femenino , Humanos , Lactante , Embarazo , Peso al Nacer/fisiología , Desarrollo Infantil/fisiología , China , Sangre Fetal/metabolismo , Recién Nacido/sangre , Efectos Tardíos de la Exposición Prenatal/sangre , Estudios Prospectivos , Glándula Tiroides/fisiología , Hormonas Tiroideas/metabolismo , Tirotropina/sangreRESUMEN
Objective@#To analyze the correlation between elective cesarean delivery and duration of breastfeeding in Ma′anshan city from 2013 to 2014.@*Methods@#From May 2013 to September 2014, a total of 3 474 pregnant women with the first prenatal checkup were recruited from Ma′anshan maternal and child health care hospital. Finally, 3 109 pregnant women were included after exclusion of those with terminated pregnancies, adverse birth outcomes, twin or multiple pregnancies, breech traction, breech midwifery and loss of delivery information. Demographic data of pregnant women, mode of delivery and breast feeding of children were collected through questionnaires and hospital records. Logistic regression model was used to analyze the relationship between elective cesarean delivery and duration of breastfeeding in children, with the mode of delivery as independent variable and the duration of breastfeeding as dependent variable.@*Results@#The age of 3 109 subjects was (26.6±3.6) years old, the rate of vaginal delivery was 51.1% (1 589), and the rate of elective cesarean delivery was 46.4% (1 443), among which the rate of non-indicative elective cesarean delivery was 26.4% (820), the rate of indicative elective cesarean delivery was 20.0% (623), and the rate of emergency cesarean delivery was 2.5% (77). The proportion of breastfeeding lasting until 4, 12 and 18 months was 45.0% (1 348/2 998), 23.7% (702/2 962) and 5.2% (154/2 944), respectively. After adjusting the confounding factors, compared with vaginal delivery, the OR (95%CI) values of breastfeeding for 4 months in indicative elective cesarean delivery and non-indicative elective cesarean delivery women were 0.870(0.714-1.059), 0.795(0.665-0.949), and the OR (95%CI) values of breastfeeding for 12 months were 0.772(0.611-0.975), 0.755(0.610-0.934), respectively.@*Conclusion@#Elective cesarean delivery may result in shorter duration of breastfeeding in children.
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Objective@#To evaluate the positive correlation between excessive screen-watching time, combined effect of screen-watching and outdoor time and the emotional problems in preschool children.@*Methods@#A total of 27 200 preschool children aged 3-6 years in 109 kindergartens in 11 cities in Jiangsu, Hubei, Anhui participated in the study. Information on both screen-watching and outdoor time and social-demographic characteristics was collected through the Questionnaire on the healthy Development of Preschool Children. Emotional problems of these children were accessed by using the Strengths and Difficulties Questionnaire (SDQ). Correlation intensity between excessive screen time and emotional problems (suspicious or abnormal) in preschool children, and the combined effects of screen-watching and outdoor time were analyzed by binary logistic regression model.@*Results@#The overall detected rate of emotional symptoms in preschool children was 17.9% (4 868/27 200). Rates showed in preschool children would include: with screen-watching time>1 h/d as 62.4% (16 983/27 200) and with outdoor time<2 h/d as 65.7% (17 873/27 200). After adjusting for confounding factors as gender, age, place of residence, family economic status, BMI, parents’ age and education level, data showed that the screen-watching time was positive correlated with emotional symptoms (OR=1.15, 95%CI: 1.08-1.24) while the outdoor time was positive correlated with emotional symptoms (OR=1.08, 95%CI: 1.01-1.16). Strong correlation between the combination of screen-watching and outdoor time and the existing emotional problems among preschool children was seen.@*Conclusions@#Excessive screen-watching time was prevalent among preschool children. Screen-watching time was positively associated with the existing emotional problems while the combined effect of screen-watching time and outdoor time was stronger.
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Objective@#To explore the association between the health literacy (HL) and smoking behaviors in middle school students.@*Methods@#From November 2015 to January 2016, middle school students in Shenyang City of Liaoning Province, Bengbu City of Anhui Province, Xinxiang City of Henan Province, Ulanqab City of Inner Mongolia Autonomous Region, Chongqing City and Yangjiang City of Guangdong Province were enrolled by using a multistage stratified cluster sampling method. A total of 23 137 questionnaires were issued and 22 628 questionnaires were valid. A questionnaire survey was conducted to collect demographic information, HL and smoking behaviors. The low, middle, and high-level group were classified according to the tertile of HL score. A multiple logistic regression model was conducted to explore the association between the HL and smoking behaviors.@*Results@#The age of subjects was (15.4±1.8) years old, and HL score was (104.1±18.7) points. The proportion of former smoking, recent smoking and passive smoking was 9.2% (2 071), 2.8% (635) and 27.9% (6 304), respectively. The proportion of former smokers who tried to quit smoking was 50.1% (1 037/2 071). Compared to the high-level HL, the low-level HL increased the risk of former smoking [OR (95%CI): 1.85 (1.61−2.13)], recent smoking [OR (95%CI): 1.68 (1.33−2.14)] and passive smoking [OR (95%CI): 1.34 (1.23−1.46)], and decreased the likelihood of smoking cessation [OR (95%CI): 0.70 (0.53−0.92)], after adjusting for the gender, school type, registered residence, household structure, accommodation type, educational level of patients, and self-reported family economic status.@*Conclusion@#The HL of middle school students was related to their smoking behaviors.