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.

Maternal anxiety during pregnancy and children's asthma in preschool age: The Ma'anshan birth cohort study

BACKGROUND

The fetal immune system and consequent elevated risk of asthma in childhood may be impacted by maternal anxiety during pregnancy. Limited studies have evaluated whether there was a sensitive period and cumulative effect of the relationship between prenatal anxiety and children's asthma.

METHODS

3131 mother-child pairs made up the study's sample from the Ma'anshan Birth Cohort Study in China. Maternal anxiety status was repeated three times using the pregnancy-related anxiety questionnaire in the 1st, 2nd and 3rd trimesters of pregnancy. Diagnostic information on asthma was collected three times at 24, 36, and 48 months of age.

RESULTS

After adjusting for confounders, children born to mothers with anxiety in the 1st, 2nd and 3rd trimesters of pregnancy all had an elevated risk of total asthma from 12 to 48 months of age. After further adjusting prenatal anxiety in the other trimesters, no association was observed between prenatal anxiety in any trimester and preschoolers' asthma. Children of mothers with persistently high anxiety score trajectory during pregnancy had an elevated risk of total asthma and high prevalence trajectory of asthma. Cumulative effects analysis showed that the more frequent the mother's anxiety, the higher the risk of her offspring developing a high prevalence trajectory of asthma from 12 to 48 months of age. The results of the subgroup analysis by age showed similar associations overall.

CONCLUSIONS

Maternal antenatal anxiety was associated with an elevated risk of preschool children's asthma, and a possible cumulative effect was observed. Maternal mental health conditions during pregnancy should receive constant attention throughout pregnancy, not just during one period.

The association between pregnancy-related anxiety and behavioral development in 18-month-old children: The mediating effects of parenting styles and breastfeeding methods

BACKGROUND

Pregnancy-related anxiety (PRA) is a distinct type of anxiety from general anxiety, affects many pregnant women, and is correlated with poor behavioral development in children. However, the mediation paths were unclear.

METHODS

A total of 2032 mother-infant pairs from the Ma'anshan Birth Cohort were included in the current study. Maternal PRA was assessed in the second and third trimesters. Children's behavioral development was evaluated at the age of 18 months. In addition, information on parenting styles and breastfeeding methods was obtained at postpartum. Multivariate regression and structural equation modeling were used to examine the associations between maternal PRA and children's behavioral development.

RESULTS

Significant intercorrelations were found between maternal PRA, the potential mediators (parenting styles and breastfeeding methods), and 18-month-old children's ASQ scores. Parenting styles played an intermediary role in the relationship between maternal PRA and children's behavioral development (β = 0.030, 95 % confidence interval: 0.017-0.051), and the mediating effect accounted for 29.1 % of the total effect. However, breastfeeding methods did not mediate the link between PRA and children's behavior.

LIMITATIONS

Depression and postpartum anxiety were not controlled for in our analysis, which left us unable to estimate the independent impact of PRA on children's behavior.

CONCLUSIONS

Parenting rather than breastfeeding is the mediating factor of behavioral problems in children caused by PRA.

[Research progress on influencing factors of early adiposity rebound in children and the effect on adolescent development in girls]

With the increasing rate of overweight and obesity in children worldwide, adiposity rebound(AR)closely related to obesity has become the spotlight, and early AR phase has a broad impact on pubertal development in girls, but the specific mechanism of action isn't very clear.This paper is review of the prevalence of early AR at home and abroad, and its influencing factors, the impact of AR on the adolescent development of girls and related mechanisms, to identify high-risk individuals with early AR, early AR to identify early adolescent development, and take early intervention measures to promote children's health.

[Independent and combined effects of pre-pregnancy BMI and gestational diabetes on early adiposity rebound timing in children]

Objective: To examine the independent and combined effects of pre-pregnancy BMI and gestational diabetes (GDM) on early adiposity rebound (AR) timing in children. Methods: Based on the "Ma'anshan Birth Cohort Study", 2 896 eligible maternal and infant pairs were recruited. In the cohort, we collected pre-pregnancy height, weight, 24 to 28 weeks GDM diagnosis, follow-up at 42 days, three months, six months, nine months of age, and every six months after one year of age, and continuously followed up to 6 years old, and obtained the child's length/height, weight, and other data. The intensity of the association between pre-pregnancy BMI, GDM, and early AR timing was analyzed by the multivariate logistic regression model. Multiplication and additive models were used to analyze how pre-pregnancy BMI and GDM influenced early AR timing in children. Results: The prevalence of underweight, average weight, overweight, and obesity before pregnancy were 23.2% (672), 66.4% (1 923), 8.7% (251), and 1.7% (50). The prevalence of GDM was 12.4%. We found that 39.3% of children had AR, and the average age at AR was (4.38±1.08). The results of multifactorial logistic regression analysis showed that pre-pregnancy overweight (OR=1.67,95%CI:1.27-2.19), pre-pregnancy obesity (OR=3.05,95%CI:1.66-5.56), and maternal GDM (OR=1.40,95%CI:1.11-1.76) were risk factors for early AR timing in children. In contrast, pre-pregnancy underweight (OR=0.60,95%CI:0.49-0.73) was a protective factor for early AR timing in children. Compared with the different effects of pre-pregnancy overweight/obesity and maternal GDM alone, the combined effect caused a higher risk of early AR timing in children, with OR values (95%CI) were 2.03 (1.20-3.44), 3.43 (1.06-11.12), respectively. The multiplication and additive models showed no interaction between pre-pregnancy BMI and GDM-influenced early AR timing in children. Conclusion: Higher pre-pregnancy BMI and maternal GDM are the independent risk factors for the early AR timing in children, and the co-occurrence of the two is higher risks, but there was no statistical interaction.

Deep Underground Laboratory Measurement of ^{13}C(α,n)^{16}O in the Gamow Windows of the s and i Processes

The ^{13}C(α,n)^{16}O reaction is the main neutron source for the slow-neutron-capture process in asymptotic giant branch stars and for the intermediate process. Direct measurements at astrophysical energies in above-ground laboratories are hindered by the extremely small cross sections and vast cosmic-ray-induced background. We performed the first consistent direct measurement in the range of E_{c.m.}=0.24 to 1.9 MeV using the accelerators at the China Jinping Underground Laboratory and Sichuan University. Our measurement covers almost the entire intermediate process Gamow window in which the large uncertainty of the previous experiments has been reduced from 60% down to 15%, eliminates the large systematic uncertainty in the extrapolation arising from the inconsistency of existing datasets, and provides a more reliable reaction rate for the studies of the slow-neutron-capture and intermediate processes along with the first direct determination of the alpha strength for the near-threshold state.

[Studies of the norm of Karitane Parenting Confidence Scale(KPCS)among parents of infants in urban areas of China]

Objective: To establish the norm of the Chinese version of Karitane Parenting Confidence Scale (KPCS) in urban areas of China. Methods: From August to December 2017, the parents of 2 216 children (<36 months old) were selected from 15 cities (Beijing, Lianyungang, Hangzhou, Chengdu, Xi'an, Guangzhou, Changsha, Jinan, Guiyang, Ningbo, Dalian, Qinhuangdao, Maanshan, Chongqing and Wuhan) in 14 provinces by stratified random sampling. The general demographic characteristics and parents' parenting confidence were collected by a self-made questionnaire and KPCS Chinese version. The percentile norm was established. P₃, P₁₀ and P₂₅ were used as the criteria to define the degree of lack of parenting confidence. Results: The age of mothers was (30.67±4.29). The age of the father was (32.50±4.99) years old. There were 726 (32.76%), 759 (34.25%) and 731 (32.99%) infants in 6-12, 12-23 and 24-35 months old groups. The total scores of P₅₀, P₂₅, P₁₀ and P₃ of KPCS (Chinese version) of infant parents in urban areas in China were 41, 38, 33, and 29 respectively. When the scores of parents were 34-37, 30-33, and ≤ 29, they were judged as mild, moderate, and severe lack of parenting confidence. There was no significant difference in the Chinese version of KPCS between parents of different age groups and parents of different gender (χ²=3.53, P=0.171; χ²=1.41, P=0.236). Each factor score≤P₃ is defined as the boundary score, and the corresponding boundary scores of "parenting" "support" and "competence" were 13, 9, and 5 respectively. Conclusion: The Chinese version of KPCS can be used to assess the parenting confidence of infants in urban areas of China. It can used as one of the bases for scientific and objective evaluation of the parenting status of families.

Effects of single and combined gestational phthalate exposure on blood pressure, blood glucose and gestational weight gain: A longitudinal analysis

Few studies have investigated the association of gestational exposure to phthalate with metabolic risk and have reached inconsistent conclusions. Based on the Ma'anshan Birth Cohort, 3273 women were included in the present study. All participants provided up to three urine samples for 7 phthalate metabolite measurements. The hazard index (HI) was used to evaluate the cumulative risk of multiple phthalate coexposures. The outcomes of interest included hypertensive disorders of pregnancy (HDOP), gestational diabetes mellitus (GDM), and gestational weight gain (GWG). The incidences of HDOP, GDM, and excessive GWG were 5.93%, 13.09%, and 28.95%, respectively. Exposure to a single phthalate metabolite or a specific diester during the first trimester of pregnancy elevated blood pressure (BP) and fasting plasma glucose (FPG) in the third trimester and body weight gain throughout pregnancy. However, inverse relationships were revealed for some phthalate metabolites, which were inconsistent with the results of their diesters. The HI value during the first trimester was positively associated with subsequent BP, FPG, and GWG. In addition, HI during the first trimester increased the risks of GDM [odds ratio (OR) = 1.34, 95% confidence intervals (CIs) = 1.02-1.75)] and excessive GWG (OR = 1.76, 95% CIs = 1.41-2.19) in a linear manner thereafter. Notably, phthalates might directly increase maternal blood glucose and pressure, and these changes were secondary effects of the obesiogenic effects of certain phthalates. In conclusion, exposure to single and multiple phthalates during the first trimester of pregnancy increased the risks of maternal metabolic syndrome components. However, the conflicting findings between phthalates and their metabolites need to be interpreted carefully.

[Effect of early-life antibiotic exposure on allergic symptoms in children aged 6-11 months and 18-23 months based a birth cohort study]

Objective: To analyze the associations between prenatal and 1-year-old exposure to antibiotics and allergic symptoms in children aged 6-11 months and 18-23 months. Methods: In this study, a prospective birth cohort study was adopted. A total of 2 122 pregnant women were enrolled in Maternal and Child Health Care Center of Ma'anshan from June 2015 to June 2016, and they were followed up from the beginning of pregnancy to children's 24 months of age. Excluding 564 pairs of mothers and children who were lost to follow-up or with incomplete information on the use of antibiotics and children's allergic symptoms, a total of 1 558 pairs of mothers and children were included in the analysis of this study. The parents and children's general demographic information, early-life antibiotic exposure and other data were collected, the information about allergic symptoms in children aged 6-11 months and 18-23 months were investigated by reference to the "International Study of Asthma and Allergies in Childhood (ISAAC)". The univariate and multivariate binary unconditional logistic regression model was used to was used to estimate associations between the effects of early-life antibiotic exposure on allergic symptoms in 2-year-old children. Results: The antibiotic usage rate of pregnant women during pregnancy was 3.4% (53), and the antibiotic usage rates of children between 0 to 2 months, 3 to 5 months, and 6 to 11 months were separately 15.2%(237), 15.5%(242) and 17.3%(269). The total prevalence of allergic diseases in children aged 6 to 11 months was 24.1% (375 children), and the total prevalence of allergic diseases in children aged 18 to 23 months was 22.0% (342 children). After adjust parental (maternal) education level, family monthly income per capita, parental (maternal) allergy history, parental (maternal) age at pregnancy, mother's Body Mass Index (BMI) before pregnancy, exposure to second-hand smoke during pregnancy, delivery method, child gender, birth weight, preterm birth, the use of antibiotics when children were 3-5 months old (RR=1.61,95%CI:1.19-2.17) and 6-11 months old (RR=1.43,95%CI:1.06-1.93) were the risk factors for allergic symptoms at 6-11 months of age; and the use of antibiotics when children were 0-2 months old (RR=1.41, 95%CI: 1.03-1.95), 3-5 months old (RR=1.54, 95%CI: 1.12-2.11) and 6-11 months old (RR=1.58, 95%CI: 1.17-2.14) were the risk factors for allergic symptoms at 18-23 months of age. Conclusion: Children's exposure to antibiotics within 1 year of age was a risk factor for allergic symptoms in children aged 6-11 months and 18-23 months, children should avoid unnecessary antibiotic use in infancy.

[Association of thallium exposure during pregnancy with maternal blood pressure and hypertensive disorder complicating pregnancy]

Objective: To investigate the association of thallium exposure during pregnancy with pregnant blood pressure changing and hypertensive disorder complicating pregnancy(HDCP). Methods: A total of 3 240 pregnant women who had establish maternal health care manual in Ma'anshan Maternal and Child Health-Care Hospital and met the inclusion and exclusion criteria were included in this study between May 2013 and September 2014.We collected their general demographic characteristics and blood pressure through questionnaire and medical records. Meanwhile we measured serum thallium concentrations by experimental technology. We use multiple logistic regression to analyze the association between thallium exposure during pregnancy and HDCP. Mixed linear model were used to analyze the association between thallium concentration and maternal systolic blood pressure (SBP) or diastolic blood pressure(DBP) in different trimesters Results: The age of 3 240 pregnant woman was (26.61±3.64) years, and the detection rate of HDCP was 5.9%(191).The median (P₂₅, P₇₅) of thallium concentrations in first trimester, second trimester and third trimester were 62.96 (50.79, 77.04), 62.19 (50.87, 75.26), 48.84 (38.00, 66.00) ng/L, respectively. Multiple logistic regression results suggested after adjusting various confounding factors, the risk of HDCP in pregnant women with high concentrations of thallium (>77.04 ng/L) in the first trimester is 1.75 (95%CI:1.01-3.03) times higher than which with low concentrations(<50.82 ng/L). Mixed linear model results suggested there are positive correlation between thallium concentrations with maternal DBP in first trimester (β=1.12, 95%CI: 0.39-1.85). Conclusion: Exposure to high levels of thallium during first trimester may increase the risk of HDCP, and the exposure of thallium may be effective to DBP of pregnant.

[A cohort study of maternal pregnancy-related anxiety at different trimesters and infants' neurobehavioral development]

Objective: To investigate the influence and critical period of pregnancy-related anxiety during pregnancy on the neurobehavioral development of infants. Methods: The subjects of this study were derived from the Ma'anshan Birth Corhot. From May 2013 to September 2014, a total of 3 474 pregnant women who registered in Ma 'anshan Maternal and Child Health Care Center were enrolled in the study. A total of 2 242 mother-infant pairs who completed three times assessments of maternal anxiety and at least once assessment of infants' neurobehavioral development were included in the final analysis. Maternal pregnancy-related anxiety was assessed by the Pregnancy-Related Anxiety Questionnaire during the first, second and third trimesters of pregnancy. When their children were at 6 and 18 months, their neurobehavioral development was evaluated using the Ages & Stages Questionnaire-China. The influence of maternal pregnancy-related anxiety on the neurobehavioral development of infants was analyzed by bi-nominal logistic regression. Results: The age of 2 242 pregnant women was (26.62±3.65) years, and the proportion of boys, low birth weight and exclusive breastfeeding for 6 months was 50% (1 120/2 242), 1.7% (38/2 242) and 11.5% (252/2 191), respectively. The detection rates of pregnancy-related anxiety during the first, second and third trimester were 24.9% (558), 28.6% (642) and 30.3% (674), respectively. After controlling confounding variables and other two trimester's anxiety, only pregnancy-related anxiety during the third trimester (not first or second trimester) significantly increased the risk of developmental delay in the domain of communication (relative risk, RR = 3.52, 95% confidence interval, CI: 1.89-6.58) and personal-social (RR=2.46, 95%CI: 1.10-5.49) at the 6 months of age, as well as in the domain of fine motor (RR=2.07, 95%CI: 1.11-3.85), problem-solving domains (RR=2.31, 95%CI: 1.24-4.31). Conclusion: Maternal pregnancy-related anxiety was associated with the risk of neurobehavioral development of infants, and the third trimester may be the critical period.

[A birth cohort study of the association between prenatal serum bisphenol A concentration and infant neurobehavior development]

Objective: To explore the association between maternal bisphenol A (BPA) exposure during pregnancy and neurobehavioral development in infant. Methods: Participants were from the Ma'anshan Birth Cohort, which was established from October 2008 to October 2010 based on four municipal medical and health institutions in Ma'anshan. High-performance liquid chromatography-tandem mass spectrometry was applied for the determination of serum BPA concentration in 1 783 pregnant women sampled at their first filing, and during 2.97 to 28.1 months age of the infants. Neurobehavioral development were assessed by 0-6-year-old pediatric examination table of neuropsychological development. Generalized linear model was used to analyze the association between serum BPA levels during pregnancy and infants' neurobehavioral development. Results: A total of 931 mother-child pairs had complete data on serum BPA detection during pregnancy and assessment of infants' neurobehavioral development status. The age of pregnant women at their first filing was (26.67±3.45) years old, and the M (P₂₅,P₇₅) of serum BPA concentration (ng/ml) was 0.23 (0.11, 0.52), with a detection rate of 84.1% (783/931). The age of infants was (13.18±5.46) months, and 53.5% (498) were boys. The developmental quotient scores of large motor, fine motor, adaptive ability, language ability and social behaviors of infants were (97.88±16.32), (97.16±15.35), (99.64±15.47), (95.3±16.04) and (98.95±14.76) points, respectively. Generalized linear model showed that after adjusting for factors such as delivery mode, feeding mode, family per capita monthly income, preterm delivery, gender, maternal age, residence, pre-pregnancy body mass index and residence time, serum BPA level in pregnancy was negatively associated with infant's development of social behavior [β (95%CI):-2.42 (-4.71, -0.12)]. The post-stratification analysis by infant age revealed that the serum BPA level in pregnancy was only negatively associated with the development of language and social behavior developmental quotient scores in infants between the ages of 12 and 18 months, with β (95%CI) about -6.66 (-13.06, -0.25) and -7.401 (-12.97, -1.83), respectively. Conclusion: BPA exposure during pregnancy affects language and social behavior development in infants, and the detection window is between 12 and 18 months old of the infant.

Domain- and trimester-specific effect of prenatal phthalate exposure on preschooler cognitive development in the Ma'anshan Birth Cohort (MABC) study

BACKGROUND

Phthalates are a group of heavily produced endocrine disruptors that are widely used in personal care products, food packaging, building materials, and medical device. Few epidemiological studies have examined the effect of repeated prenatal exposure to multiple phthalates on preschooler cognitive development.

OBJECTIVES

This study aimed to examine the association between prenatal phthalate exposure measured at multiple time points and the intelligent quotient (IQ) scores of preschoolers, and to further identify the critical windows and specific intelligence domains in which phthalate exposure would affect preschooler cognitive development.

METHODS

The current study was based on the Ma'anshan Birth Cohort (MABC) study. Seven phthalate metabolites were measured in 2128 maternal urine samples collected during the first, second, and third trimesters of pregnancy. The IQ score of preschool-aged children were assessed with the Chinese version of the Wechsler Preschool and Primary Scale of Intelligence, Fourth edition (WPPSI-Ⅳ CN). Linear mixed models (LMMs) were used to assess the longitudinal effects of repeated prenatal phthalate exposure on children's IQ score. Multiple linear regression models were fitted to determine whether critical window phthalate exposure would affect cognitive development of children.

RESULTS

Overall, the repeated measures analysis indicated that the verbal comprehension index (VCI), visual space index (VSI) and full-scale intelligence quotient (FSIQ) decreased by 0.30 (95% CI: -0.60, 0; p = 0.05), 0.32 (95% CI: -0.62, -0.01; p = 0.04), and 0.31 (95% CI:-0.57, -0.04; p = 0.02) points, respectively, with each ln-transformed increase in the metabolite concentration of MBP. The fluid reasoning index (FRI) and processing speed index (PSI) increased by 0.30 (95% CI: 0.07, 0.54; p = 0.01) and 0.28 (95% CI: 0.06, 0.51; p = 0.01) points, respectively, with each ln-concentration increase in MEP. Trimester-specific regression models stratified by the sample collection time during pregnancy generated consistent results. In the first trimester, each ln-transformed MBP increase was associated with reductions in VCI, VSI and FSIQ of 0.56 (95% CI:-1.09, -0.02; p = 0.04), 0.60 (95% CI:-1.15, -0.05; p = 0.03) and 0.49 (95% CI:-0.97, -0.01; p = 0.04) points, respectively. In the third trimester, we observed that only MBzP exposure was associated with an increase in VCI (β: 0.48, 95% CI: 0.03, 0.92; p = 0.04). The gender-stratified analyses revealed that boys drove these associations.

CONCLUSIONS

Our results suggest that prenatal phthalate exposure impairs the cognitive development of preschoolers. The first trimester of pregnancy might be the most vulnerable period in terms of neurotoxicitydue to phthalate exposure. These findings warrant further confirmation.

[Association of antenatal anxiety with preterm birth and low birth weight: evidence from a birth cohort study]

Objective: To investigate the impacts of antenatal anxiety on preterm birth and low birth weight. Methods: Women in early pregnancy were recruited for follow-up, antenatal anxiety in three trimesters was screened using Self-Rating Anxiety Scale and the score ≥50 was regarded as anxiety. Logistic regression analysis was conducted to evaluate the associations of the anxiety in three trimesters, new onset anxiety in the second and third trimesters with infant birth outcomes, such as preterm birth and low birth weight. Results: The rates of anxiety in the first, second and third trimesters of pregnancy were 12.5%, 3.7%, and 7.4% respectively. We found that there was no statistical association between anxiety in the first and second trimester and preterm birth. The anxiety in the third trimester was associated with increased odds for preterm birth (OR=3.55, 95%CI: 1.62-7.82). Associations between anxiety in all three trimesters and low birth weight were not significant. New onset anxiety in the third trimester was associated with significant increased risk of premature delivery (OR=5.20, 95%CI: 1.84-14.70) and low birth weight (OR=6.93, 95%CI: 2.42-19.88). Conclusions: Our study showed that anxiety in the third trimester is an important risk factor for premature delivery, new onset anxiety symptoms in the third trimester can significantly increase the incidence of premature birth and low birth weight of infant.

[The relationship between maternal pregnancy-related anxiety and executive function in preschool children: a cohort study]

Objective: To investigate the relationship between pregnancy-related anxiety and executive function in preschool children. Methods: From October 2008 to October 2010, pregnant women and live births were enrolled in the study. The expectant pregnant women and their live singleton fetuses were recruited from the antenatal care clinic of Ma'anshan maternal and Child Health Care Hospital. The cohort was followed up from April 2014 to June 2015. A total of 3 556 pairs of maternal and child were included in the final analysis. The questionnaire was used to collect the relevant information of pregnant women and the follow-up data of children. Pregnancy-related anxiety was assessed by using the Pregnancy-Related Anxiety Questionnaire, and the executive function of preschool children was assessed by using the Behavior Rating Inventory of Executive Function-Preschool (BRIEF) (Parent Version). Bi-nominal logistic regression was used to analyze the effect of pregnancy-related anxiety on executive function in preschool children. Results: The average age of 3 556 pregnant women was (26.78±3.42) years old, and the average age of preschool children was (4.32±0.46) years old. The proportion of primipara, only child and urban children was 94.96% (3 375/3 556), 91.37% (3 249/3 556) and 88.98% (3 164/3 556), respectively. The prevalence of pregnancy-related anxiety in the 1(st) and 3(rd) trimester was 17.60% (626/3 556) and 6.30% (224/3 556) respectively. The prevalence of abnormal global executive composite was 8.54% (304/3 556). The prevalence of anxiety in both trimesters was 7.68% (273/3 556). After controlling for confounding factors such as monthly family income, education years of parents, maternal age, pre-pregnancy weight, previous adverse pregnant outcomes, number of pregnancy, pregnant complications, the main residence of the children in the past six months, and Z score of birth weight, compared with the group without pregnancy-related anxiety in either 1(st) or 3(rd) trimester, pregnancy-related anxiety in the 1(st) trimester increased the risk of preschool children's abnormality in inhibition, working memory, planning/organization and global executive composite, and the OR (95%CI) value was 1.52 (1.08-2.13), 1.41 (1.14-1.74), 1.62 (1.13-2.33), and 1.60 (1.18- 2.17), respectively. Anxiety in the 3(rd) trimester increased the risk of children's abnormality in inhibition and global executive composite, and the OR (95%CI) value was 1.90 (1.15-3.12) and 1.69(1.05-2.71). Pregnancy-related anxiety in both trimesters increased the risk of abnormality in inhibition, working memory, planning/organization, and global executive composite in preschool children, and the OR (95% CI) value was 2.41 (1.61-3.62), 2.19 (1.66-2.88), 1.80 (1.11-2.92), and 2.41 (1.65-3.52), respectively. Conclusion: The exposure to pregnancy-related anxiety during pregnancy increases the risk of executive dysfunction in preschool children.

Repeated measures of prenatal thallium exposure and placental inflammatory cytokine mRNA expression: The Ma'anshan birth cohort (MABC) study

Thallium (Tl), a ubiquitous environmental toxicant, can cross the placental barrier during pregnancy. However, the effects of prenatal Tl exposure on placental function are currently unclear. Based on the Ma'anshan Birth Cohort study, we examined whether long-term prenatal Tl exposure was associated with placental inflammation. Tl concentrations were quantified in serum samples (n = 7050) from 2515 pregnancy during each trimester, placental inflammatory cytokine mRNA expression was assessed in 2519 placenta tissues. Geometric mean values of serum Tl concentrations were 63.57, 63.63 and 48.71 ng/L for the first, second and third trimesters, respectively. After adjustment for potential confounders, serum Tl concentration was positively associated with CD68 (β: 0.30; 95% CI: 0.05, 0.56) in the first trimester and TNF-α (β: 0.12; 95% CI: 0.01, 0.23), IL-6 (β: 0.15; 95% CI: 0.05, 0.25) and CD68 (β: 0.25; 95% CI: 0.10, 0.39) in the third trimester, however was negatively associated with IL-4 (β: -0.21; 95% CI: -0.41, -0.01) and CD206 (β: -0.23; 95% CI: -0.45, -0.02) in the first trimester. Repeated measures analysis showed that TNF-α, IL-6 and CD68 increased by 0.11 (95% CI: 0.01, 0.21), 0.12 (0.15, 95% CI: 0.05, 0.25), 0.22 (95% CI: 0.10, 0.39), respectively, with each 1ln-transformed Tl increase in total samples. Gender-specific analyses revealed that these associations were largely driven by male offspring. In addition, immunohistochemistry revealed that nuclear NF-κB p65 expression increased in placenta tissue. The results of this prospective cohort study provide longitudinal evidence that prenatal Tl exposure induces a placental inflammatory response in the Chinese population.

Constraining the External Capture to the ^{16}O Ground State and the E2 S Factor of the ^{12}C(α,γ)^{16}O Reaction

The ^{12}C(α,γ)^{16}O reaction is one of the most crucial reactions in nuclear astrophysics. The E2 external capture to the ^{16}O ground state (GS) has not been emphasized in previous analyses but may make a significant contribution to the ^{12}C(α,γ)^{16}O cross section depending on the value of the GS asymptotic normalization coefficient (ANC). In the present work, we determine this ANC to be 337±45  fm^{-1/2} through the ^{12}C(^{11}B,^{7}Li)^{16}O reaction using a high-precision magnetic spectrograph. This sheds light on the existing large discrepancy of more than 2 orders of magnitude between the previously reported ANC values. Based on the new ANC, we experimentally constrain the GS external capture and show that through interference with the high energy tail of the 2^{+} subthreshold state, a substantial enhancement in the GS S_{E2}(300) factor can be obtained (70±7  keV b) compared to that of a recent review (45 keV b), resulting in an increase of the total S factor from 140 to 162 keV b, which is now in good agreement with the value obtained by reproducing supernova nucleosynthesis calculations with the solar-system abundances. This work emphasizes that the external capture contribution for the ground state transition cannot be neglected in future analyses of the ^{12}C(α,γ)^{16}O reaction.

[Association between elective cesarean delivery and duration of breastfeeding in Ma'anshan City from 2013 to 2014]

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.

[The relationship of maternal and umbilical cord blood zinc level associated with newborn birth weight: a birth cohort study]

Objective: To study serum zinc level in pregnancy and umbilical cord blood and their association with newborn birth weight. Methods: Pregnant women accepting obstetric examination in Ma'anshan Maternal and Child Care Center were recruited from May 2013 to September 2014. The follow up was conducted during their first, second and third trimesters of pregnancy and the self-designed questionnaire was used to collect information of social and demographic characteristics. Blood samples in the first, second pregnancy period and umbilical cord blood samples were collected and serum concentrations of zinc were assayed. 3 239 mother-infant entered the final analysis. We divided serum zinc level into low (<P(25)), medium (P(25)-P(75)) and high (>P(75)) groups according to their exposure concentrations at each trimesters. Non-conditional multivariate logistic regression model was conducted to evaluate the association between serum zinc level in first, second trimesters of pregnancy and umbilical cord blood with small for gestational age (SGA) and large for gestational age (LGA). Results: Serum zinc level in P(50) (P(25)-P(75)) during the first, second trimesters and cord blood were 1 016.18 (907.09-1 145.60), 813.36 (732.47-897.89) and 903.44 (808.71-1 015.64) μg/L, respectively. The prevalence of zinc deficiency during the first, second trimesters and cord blood were 1.5% (44/2 957), 15.9% (492/3 087) and 6.5% (176/2 707), respectively. The prevalence of total SGA and LGA were 9.7% (313/3 239) and 16.5% (536/3 239), respectively. Compared to high-level serum zinc group, the risk of SGA (OR (95%CI) in low-level serum zinc group during first trimesters was 1.51 (1.05-2.19)). Serum zinc level among second pregnancy period and umbilical cord blood had no statistically significant effect on SGA and LGA (both P values >0.05). Conclusion: Zinc nutritional status of pregnant women in Ma'anshan city was at a good level. The low serum zinc level in first trimester increased the risk of SGA.

[Practice of parenting and related factors on children aged 0-5 in the urban areas of China]

Objective: To characterize the relations between the practice of parenting and associated factors on children (0-5 years old) in urban areas of China, in order to provide evidence for promoting the early development of children and to provide positive guidance and service programs on parenting. Methods: A total of 4 515 parents from 15 cities (14 provinces) were surveyed with a self-administered questionnaire. Parenting and Family Adjustment Scales (PAFAS) was used, including parameters as: consistency and coercive parenting, positive encouragement, parent-child relationship and parental emotion adjustment, family relationship and parental teamwork aspects, etc. Both single factor analysis and multiple linear regression were used to examine the associations between parenting practice, individual, parental and family factors. Results: The mean score of PAFAS was 21.00 (15.00-28.00), associated with factors as children's age, only-child family, premature delivery, father's education level, confidence on parenting, problems regarding the parental mood, annual family income, family structure and behavior on seeking professional help, etc. Results showed that there were big differences on the practice of parenting in China and influenced by variety of factors. Conclusions: The general situation of parenting was well, in the urban areas of China. The practice of parenting was associated with a series of individual, parental and family factors. Programs on improving the parenting skills and promoting the early development of children, should be highlighted.

Trace element profiles in pregnant women's sera and umbilical cord sera and influencing factors: Repeated measurements

In utero exposure to toxic heavy metals and deficient or excessive essential trace elements during pregnancy may have adverse effects on pregnant women and their offsprings, which are of great concern. The objective of the present study was to characterize serum concentrations of multiple trace elements at multiple time points during pregnancy in Chinese women. Three thousand four hundred and sixteen pregnant women in total were included from MABC (Ma'anshan Birth Cohort) study. Fasting sera in the morning and questionnaires were obtained at three separate follow-up visits. Nineteen trace elements from serum samples were analyzed, including aluminum (Al), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As), selenium (Se), cadmium (Cd), barium (Ba), thallium (Tl), lead (Pb), calcium (Ca), magnesium (Mg), mercury (Hg) and molybdenum (Mo). The total detection rates for most elements were 100% rather than Ni (99.98%), As (99.97%), Cd (99.6%), Ba (99.9%), Pb (99.8%), Hg (99.8%). The concentration distributions of 19 elements varied vastly. Median concentrations for all trace elements ranged from 38.5 ng/L to 102.9 mg/L. The moderate interclass correlation coefficients (ICCs) were observed for Co, Cu, Se and Hg, ranging from 0.40 to 0.62; the lower ICCs, ranging from 0.13 to 0.32 were for Fe, Zn, Cd, Ba, Tl, Mg and Mo. The intraclass correlation effects were not observed for the remaining elements, such as Al, V, Cr, Mn, Ni, As and Pb. The concentrations of each element between three time points were significantly different; significant differences were also found between any two time points except for Ni, Cd and Mo. Many factors could affect the levels of trace elements, and a very important factor of them was season. Consequently, a single measurement of elements in sera seems not enough to describe exposure levels throughout pregnancy; additionally, season affected exposure levels of trace elements with moderate ICCs showed certain regularity. Future analyses should take sampling seasons into consideration carefully.

Association between maternal and umbilical cord serum cobalt concentration during pregnancy and the risk of preterm birth: The Ma'anshan birth cohort (MABC) study

Cobalt is an essential trace element and has been suggested to be involved in oxidative stress and inflammatory responses. However, researches have paid little attention to the association between serum cobalt levels during pregnancy and the risk of preterm birth (PTB, <37 week of gestation). The purpose of this study was to determine the association between maternal and umbilical cord serum cobalt concentrations and the risk of PTB. A total of 2951, 3080, and 2698 serum samples were obtained from pregnant women in the first, the second trimester, and the umbilical cord blood, respectively. The tertile levels of ln-transformed cobalt were defined as low, medium and high levels for cobalt respectively. In our study, the rate of PTB (<37 weeks of gestation) was elevated in subjects with low cobalt levels in the first trimester of pregnancy (adjusted OR 1.61, 95% CI: 1.01, 2.58) and the second trimester of pregnancy (adjusted OR 1.62, 95% CI: 1.03, 2.54). The adjusted OR for PTB was 2.46 (95% CI: 1.34, 4.53) among subjects with low cobalt levels and 2.22 (95% CI: 1.19, 4.15) among subjects with medium cobalt levels in the umbilical cord serum. Our findings demonstrated that the lower levels in maternal and umbilical cord serum cobalt were associated with the increased the risk of PTB.

[The associations between nighttime sleep duration, bedtime and preschool children's obesity]

Objective: To examine the relationship of nighttime sleep duration and bedtime with preschool children's obesity, and to explore possible early life risk factors for childhood obesity. Methods: A total of 14 946 valid children from 16 439 pre-school children aged 3-6 years in 91 kindergartens in Ma'anshan city participated in the study. The body mass index cut-offs for overweight and obesity in Chinese children and adolescents aged 2-18 years was used as the criterion for judging overweight and obesity, and pathological and secondary causes of obesity were excluded. The associations of nighttime sleep duration and bedtime with preschool children's obesity was analyzed by using non-conditional multivariate binary logistic regression model. Results: Among the preschool children, 22.4% (n=3 345) had shorter sleep duration. 9.5% (n=1 415) had bedtimes after 22:00 on weekdays and 21.8% (n=3 260) had bedtimes after 22:00 on weekends. The prevalence of overweight and obesity were 16.5% (n=2 466) and 10.5% (n=1 562), respectively. After the adjustent of age, gender, whether or not only child, residence in the last six months, parents' body mass index parents' educational level, diet preference, outdoor activities, TV viewing duration, sleep duration, bedtime on weekdays and weekends, only the shorter sleep duration (OR=1.25, 95%CI: 1.03-1.51) was still positively associated with the prevalence of obesity in preschool children. Conclusion: Shorter sleep duration was positively associated with the prevalence of obesity among preschool children.

[Effect of breastfeeding on the behavioral development of infants and children: a birth cohort study in Ma'anshan]

Objective: To discuss the relationship between breastfeeding and the behavioral development of infants and children. Methods: Based on the Ma'anshan Birth Cohort Study, there were 3 474 pregnant women recruited from Ma'anshan Maternal and Child Care Center between May 2013 and September 2014, including 3 273 singleton live births. Follow up the infants to the age of 18 months old. Excluded the infants with incomplete information of breastfeeding and who did not finish the ASQ-3 evaluation in 6 months old and 18 months old, 2 404 valid subjects were included in the study. The information of demographic characteristics, deliver, infants and breastfeeding was collected. The behavioral development were evaluated by the third edition of Ages and Stages Questionnaire (ASQ-3) at 6 months old and 18 months old, and the effect of breastfeeding on behavioral development among infants and children were analyzed by multivariable logistic regression model. Results: The intensity of breastfeeding of infants within 6 months old was (26.56±10.56). The rate of breastfeeding as pure or major intake for infants between 0-5 months old were separately 54.2% (1 303), 54.0% (1 298). 54.0% (1 297), 50.5% (1 213), 34.4% (827) and 9.9% (237). After age, pre-pregnant BMI, intelligence, delivery mode, gender, gestational age, birth weight and family economic status adjusted, compared to never-breastfeeding, continuous breastfeeding for 1-3 months could protect children from severe developmental delay in fine motor domain aged 6 months old (RR=0.36, 95%CI: 0.17-0.79), communication domain aged 18 months old (RR=0.27, 95%CI: 0.08-0.88), and social domain aged 18 months old (RR=0.36, 95%CI: 0.21-0.63). Compared to never-breastfeeding, continuous breastfeeding for more than 4 months could protect children from severe developmental delay in fine motor domain aged 6 months old (RR=0.58, 95%CI: 0.34-0.97), communication domain (RR=0.57, 95%CI: 0.39-0.83) and mild developmental delay (RR=0.65, 95%CI: 0.48-0.87) aged 18 months old and fine motor domain (RR=0.57, 95%CI: 0.39-0.83) aged 18 months old and social domain aged 18 months old (RR=0.57, 95%CI: 0.39-0.83). With the breastfeeding intensity rising, there were less children evaluated as severe development delay in communication domain aged 6 months old, communication, fine motor and problem-solving domains aged 18 months old, with RR (95%CI) at 0.98 (0.96-1.00), 0.96 (0.93-0.99), 0.98 (0.97-1.00) and 0.98 (0.96-1.00); and less children evaluated as mild development delay in communication domain aged 18 months old with RR (95%CI) at 0.99 (0.98-1.00). Conclusion: Breastfeeding with longer duration and increased intensity could promote better development in children.

Repeated measures of prenatal phthalate exposure and maternal hemoglobin concentration trends: The Ma'anshan birth cohort (MABC) study

A prospective cohort study of a Chinese population was conducted to investigate the relationship between prenatal phthalates exposure and maternal hemoglobin or anemia. Based on the Ma'anshan Birth Cohort study, 7 phthalate metabolites were quantified in spot pregnancy urine samples (n = 9263) from 3269 pregnant women during each trimester. The maternal hemoglobin concentrations were obtained from electronic medical records at the same three time points for each participant during pregnancy. Anemia was defined as a hemoglobin concentration below 110 g/L in pregnant women. Repeated measures and trimester-specific analyses were used to estimate the effects of phthalates exposure on maternal hemoglobin and anemia. The prevalence of anemia was 3.6%, 27.0%, and 26.5% during the first, second and third trimester, respectively. Repeated measures analysis showed that hemoglobin concentrations decreased by 0.55, 0.19, 0.57, 0.49, and 0.54 g/L with each 1 ln-transformed concentration increase of MBP, MBzP, MEHP, MEOHP, and MEHHP, respectively. Exposure to MMP, MBP, MEHP, MEOHP, and MEHHP increased the risk of anemia by 1.11-fold, 1.21-fold, 1.20-fold, 1.13-fold, and 1.16-fold, respectively. Trimester-specific regression models stratified by the sample collection time during pregnancy generated consistent results. This is the first study focusing on the effect of prenatal phthalate exposures on hemoglobin or anemia in pregnant Chinese women. We found that prenatal phthalates exposure not only decreased the concentrations of hemoglobin but also showed associations with the prevalence of anemia. Associations appeared stronger for the subsample representing women pregnant with a male fetus than those pregnant with a female fetus. Anemia remains a moderate public health problem in China, and effective measures should be implemented.

[Association between early pregnancy bisphenol A exposure and sleep problems among preschool children]

Objective: To analyze the association between maternal bisphenol A exposure during early pregnancy and sleep problems among preschool children. Methods: Research subjects were from one of the sub-cohorts(Ma'anshan Cohort) of the China-Anhui Birth Cohort Study (C-ABCS) in Ma'anshan city. The basic situation of pregnant women and sleep information of preschool children were investigated. We selected preschool children whose mother's maternal serum bisphenol A concentrations of the first trimester had been already detected between December 2012 to Januray 2014. 1 259 pairs of mothers and children were included. The concentrations of bisphenol A exposure during early pregnancy were divided into low, medium and high exposure groups according to 25(th) percentile (P(25)) and 75(th) percentile (P(75)) levels. Multivariate multinomial logistic regression model was used to analyze the association between maternal bisphenol A exposure during early pregnancy and sleep-related problems in preschool children. Results: The P(50) (P(25)-P(75)) of serum bisphenol A exposure level during early pregnancy was 0.231 (0.106-0.512) ng/ml. The sleep-related problems scores of 1 259 preschool children were (16.43±3.82) points. The occasional sleep-related problems were detected about 47.8% (602 cases) and frequent sleep-related problems were detected about 18.3% (230 cases). After the adjustment of the confounding factors such as children's gender, age, BMI, sleep position (lying down, sleeping on one's back), the length of time to sleep and the length of sleep at night, in comparison with bisphenol A low exposure group, the OR (95%CI) value of preschool children with occasional sleep-related problems in maternal bisphenol A high exposure group during early pregnancy was 1.44 (1.01-2.06). After the gender stratification, the results showed that in comparison with bisphenol A low exposure group, the OR (95%CI) value of preschool girls with occasional sleep-related problems in maternal bisphenol A medium and high exposure group during early pregnancy were 1.61 (1.05-2.46) and 2.40 (1.42-4.04), respectively. The OR (95%CI) value of preschool girls with frequent sleep-related problems in maternal bisphenol A high exposure group during early pregnancy was 2.64 (1.34-5.17). However, in boys, there was no statistically significant association between maternal bisphenol A exposure during early pregnancy and sleep-related problems (P>0.05). Conclusion: Maternal bisphenol A exposure during early pregnancy might be related to sleep-related problems in preschool children.

[Developmental characteristics of circadian rhythms in hypothalamic-pituitary-adrenal axis during puberty]

Objective: To explore the developmental characteristics of circadian rhythms in hypothalamus-pituitary-adrenal (HPA) axis during puberty. Methods: A total of 1 070 students from Grade 2-3 in 3 primary schools in Ma'anshan city, Anhui province, were selected for physical examination and circadian rhythm of HPA axis checked from 2015 to 2017. Saliva samples were collected at each of the following three time points: immediately upon wakening, 30 minutes after wakening and bedtime, with the index of circadian rhythm of HPA axis calculated, which including cortisol awake response (CAR), cortisol in puberty priming and diurnal cortisol slope (DCS). Testicular volume, palpation and visual inspection of breast development were used to assess the state of purbety development on boys and girls. Information on gender, date of birth, time to fall asleep, wake-up time and weekly physical activity were gathered through questionnaire survey. Non-parametric test was used to compare the differences of baseline, follow-up period and different adolescent developmental processes of each index on circadian rhythm of HPA axis. Results: During the period of follow-up program and comparing with the continuous undeveloped group, CAR and the changes of CAR showed significantly increase, both in the puberty priming group and continuous development group, with statistically significant differences (CAR: Z=8.551, 4.680, respectively; P<0.01; the changes of CAR: Z=4.079, 2.700, respectively, P<0.01). There were no significant differences noticed in CAR and the changes of CAR between puberty priming group or continuous development group. The area under the curve (AUC) of cortisol in puberty priming group was slightly higher than that in the persistent undeveloped group (Z=2.591, P=0.010). Both the changes of daily cortisol slope (DCS) in puberty priming group and continuing developed group decreased significantly, when comparing with those in continuous undeveloped group (Z=-2.450, Z=-2.151; all P<0.05). There was no significant difference noticed in the changes of cortisol in puberty priming and DCS between different puberty development stages (the changes of AUC: χ(2)=2.747, P=0.253; DCS: χ(2)=4.554, P=0.032). Conclusions: The indexes of circadian rhythm of HPA axis were associated with the development of puberty. Both the cortisol awakening response and the total amount of diurnal cortisol secretion showed an increase, along with the puberty development. The change of diurnal cortisol slope declined with the development of puberty.

[Epidemiological characteristics and relevant factors on the comorbidity of hyperactivity behavior and allergic diseases in preschool children]

Objective: To understand the epidemiological characteristics and relevant factors on the comorbidity of hyperactivity behavior and allergic disease among preschool children in urban areas of Ma'anshan city. Methods: During April 2014 to April 2015, 91 kindergartens over 3 years old were investigated. In the investigation, 16 439 questionnaires were distributed to parents, and 15 291 valid questionnaires were collected. Conners abbreviated symptom questionnaire (brief symptom questionnaire) was filled out by parents to assess the children's hyperactive behaviors. Information of allergic disease history was reported by parents, including allergic dermatitis/eczema, food/drug allergy, allergic rhinitis and asthma. Multivariate unconditional logistic regression was used to analyze the relevant factors of comorbidity of hyperactivity behavior and allergy diseases. Results: The average age of the 15 291 children were (4.5±1.0) years old, among which 53.7% (8 218/15 291) were boys. The prevalence of hyperactive behaviors was 8.6%(1 317/15 291), and the comorbidity rate of hyperactivity and allergic deseases was 1.7% (258/15 291). After confounding factors including gender, age, delivery mode, father's age and pregnancy complications adjusted, poor sleep quality (OR=4.45, 95%CI: 2.85-6.94), long duration of watching TV at weekend (OR=1.39, 95%CI: 1.00-1.94) and poor eating behavior (OR=1.78, 95%CI: 1.07-2.98) were relevant factors of the comorbidity of hyperactivity and allergic diseases. Conclusion: The prevalence of comorbidity of hyperactivity behavior and allergic disease among preschool children in urban areas of Ma'anshan city was not high. Poor night sleep quality, long duration of watching TV and frequently picky eating were relevant factors of the comorbidity of hyperactive behaviors and allergic diseases.

[Association between pregnancy-related anxiety of pregnant women and autism-like behavior in their offspring at 18 months of age]

Objective: To investigate the relationship of pregnancy-related anxiety of pregnant women in second/third trimesters and autism-like behaviors in their offspring at 18 months of age. Methods: Based on a prospective cohort study design, we evaluated the situation of pregnancy-related anxiety of women during second and third trimesters through a Pregnancy-Related Anxiety Questionnaire. Subjects under study were classified into three groups, 1) those with pregnancy- related anxiety during both trimesters, 2) those with pregnancy-related anxiety at one trimester and 3) those without pregnancy-related anxiety in either trimester. When their children were 18 months, autism-like behaviors (ALB) were evaluated, using the part A of Checklist for Autism in Toddlers-23, and then classified into three groups as non-ALB group, minor ALB group and major ALB group. Multi-nominal logistic Regression was used to analyze the relationship of pregnancy-related anxiety with autism-like behaviors. Results: Compared with non-ALB group, children whose mother with pregnancy-related anxiety during both trimesters presented significant higher risk on ALB than children whose mother without pregnancy-related anxiety in these two periods (relative risk, RR=2.43, 95% CI: 1.21-4.86, P=0.012), major factors as pregnant women's IQ and gestational diabetes mellitus, premature delivery and education levels of fosterers on these pregnant women were under control. Our results from the stratified analysis showed: when in the subgroup that mother was the main fosterer of the child, there was an significant increase of risk in children whose mothers with pregnancy-related anxiety during both trimesters (RR=4.22, 95%CI: 1.73-10.32, P=0.002). Conclusion: The association between pregnancy-related anxiety and autism-like behavior was not strong but influenced by the fosterer of the child.

Thyroid autoantibodies in pregnancy are associated with hypertensive disorders of pregnancy: Ma'anshan Birth Cohort Study

OBJECTIVE

Hypertensive disorders of pregnancy (HDP) have been associated with adverse health outcomes for both mothers and children. Previous studies examining associations of maternal thyroid autoantibodies with HDP indicate conflicting results. The objective of this study was to examine associations of maternal thyroid autoantibody positivity in the first and the second trimesters with the risk of HDP.

DESIGN, PARTICIPANTS AND MEASUREMENTS

In the Ma'anshan Birth Cohort study, a population-based prospective study in China, a total of 3474 pregnant women were enrolled between May 2013 and September 2014. Thyroid autoantibodies, including antithyroperoxidase autoantibody (TPOAb) and antithyroglobulin autoantibody (TgAb), as well as thyroid function tests, were measured in both the first and the second trimesters in 2893 pregnant women. Multivariate logistic regression analyses were conducted to calculate the odds ratio (OR) and 95% confidence interval (CI) for the associations between thyroid autoantibodies and HDP.

RESULTS

Multivariate logistic regression analyses showed that TPOAb positivity in the first trimester was associated with a 1.80 (95% CI = 1.17-2.78) increased odds of HDP after adjustment for confounders, which was mainly due to an increased risk of gestational hypertension (OR = 1.93, 95% CI = 1.17-3.18). In addition, TgAb positivity in the first trimester was associated with a higher risk of HDP (OR = 1.78, 95% CI = 1.16-2.73) after adjustment for confounders, which was mainly due to an increased risk of gestational hypertension (OR = 1.89, 95% CI = 1.15-3.11). These associations were also seen among euthyroid women. Women with positive TPOAb in the second trimester seemed to have a higher risk of gestational hypertension (OR = 1.87, 95% CI = 1.02-3.43) after adjustment for confounders. However, among euthyroid women, TPOAb positivity in the second trimester was not associated with HDP. The TgAb status in the second trimester was not associated with HDP.

CONCLUSIONS

Our results show that TPOAb positivity and TgAb positivity in the first trimester are associated with an increased risk of HDP. These data demonstrate that these associations are even seen among euthyroid women.

Impact of maternal thyroid autoantibodies positivity on the risk of early term birth: Ma'anshan Birth Cohort Study

PURPOSE

We aim to investigate associations of maternal serum anti-thyroperoxidase autoantibody (TPOAb) with duration of gestation. We aim to investigate whether maternal TPOAb positivity is associated with the risk of premature or early term birth.

METHODS

This was a prospective birth cohort study performed in an iodine sufficient area of China. Serum samples were collected from 2931 women at both the first and second trimesters of pregnancy. Thyrotropin (TSH), free thyroxine (FT4), and TPOAb levels were measured. Data on gestational age at birth was obtained from delivery records.

RESULTS

The prevalence of early term birth was 23.8%, while the prevalence of premature birth was 4.2%. The prevalence of TPOAb positivity was 12.1% in the first trimester and was 7.2% in the second trimester. Gestational age at birth was inversely associated with lgTPOAb both in the first trimester (β, -0.283, 95% CI -0.408, -0.158; P < 0.001) and in the second trimester (β, -0.174, 95% CI -0.319, -0.030; P = 0.018), after adjustment for potential confounding factors. There was a positive association of TPOAb positivity with the risk of early term birth both in the first (OR = 1.691, 95% CI 1.302, 2.197) and second trimesters (OR = 1.644, 95% CI 1.193, 2.264), after adjustment for potential confounding factors. TPOAb positivity in the second trimester was associated with a 1.863-fold higher risk of premature birth (OR = 1.863, 95% CI 1.009, 3.441), after adjustment for potential confounding factors.

CONCLUSIONS

Our results show that TPOAb is associated with shorter duration of gestation and with higher risk of premature and early term birth.

[Potential interaction effect on attention-deficit/hyperactivity disorder between mother's educational level and preschoolers' dietary pattern]

Objective: To explore the interaction effect between mother's educational level and preschoolers' dietary pattern on attention-deficit/hyperactivity disorder (ADHD). Methods: In 2014, there were 16 439 children aged 3-6 years old from 91 kindergartens in Ma'anshan municipality of China. A semi-quantitative food frequency questionnaire and the 10-item Chinese version of the Conners' Abbreviated Symptom Questionnaire (C-ASQ) were administered to assess the usual dietary intake and symptoms on ADHD. Social-demographic information was collected through questionnaires. Unconditional logistic regression was used to analyze the multiplication interaction effect between mother's educational level and preschoolers' dietary pattern on ADHD. Excel software was used to analyze the additive interaction effect of mother's educational level and preschoolers'dietary pattern on ADHD. Results: Results showed that factors as: mother's low educational level[aOR=1.31 (1.13-1.52)], scores related to preschoolers in the top quintile of "food processing" [aOR=1.31 (1.16-1.48)] and "snack" [aOR=1.45 (1.29-1.63)]patterns showed greater odds while preschoolers in the top quintile of "vegetarian" [aOR=0.80 (0.71-0.90)]showed less odds for having ADHD symptoms. Both multiplication and additive interactions were observed between mothers with less education. The processed dietary patterns (OR=1.17, 95%CI: 1.11-1.25), relative excess risk of interaction (RERI), attributable proportion (AP) and the interaction index (SI) appeared as 0.21, 0.13 and 1.47, respectively. Multiplication interaction was observed between levels of mother's low education and the snack dietary pattern (OR=1.21, 95%CI: 1.14-1.29), with RERI, AP and SI as 0.49, 0.26 and 2.36, respectively. However, neither multiplication interaction or additive interaction was noticed between levels of mother's low education and the vegetarian dietary pattern (OR=0.97, 95%CI: 0.92-1.03), with RERI, AP and SI as 0.09, 0.05 and 1.15, respectively. Conclusions: Levels of mother's low education presented a risk factor for ADHD symptoms in preschool children. Both multiplication interaction and additive interaction were observed between mother's low education levels and the processed dietary pattern. Multiplication interaction was noticed between mother's education levels and the snack dietary pattern but not with the vegetarian dietary pattern.

[Association between the internal exposure levels of phthalates and executive function of preschool children]

Objective: To investigate the association between the internal exposure levels of phthalic acid esters (PAEs) and executive function (EF) of preschool children. Methods: Between October 2008 and October 2010, pregnant women who accepted pregnancy health care services in four municipal medical and health institutions in Ma'anshan city, Anhui Province, were recruited as study objects. A total of 5 084 pregnant women and 4 669 singleton live births were enrolled in this cohort. The follow-up study was conducted from April 2014 to April 2015. A total of 3 725 data-completed preschool children aged 3 to 6 years older entered in this study. The method of analysis seven metabolites of phthalates in urine was high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) and divided objects into low (P(0)-P(24)), medium (P(25)-P(74)) and high (P(75)-P(100)) groups according to their exposure concentrations. To investigate the executive function of preschool children, we used the Behavior Rating Inventory of Executive Function-Preschool Version (BRIEF-P). Univariate and multivariate statistical method was used to analyze the etiology association between the phthalate metabolites levels and preschool children's executive function. Results: In this study, 53.6% (1 997/3 725) of preschoolers were boys, children's age was (51.5±5.6) months. The detection rates of seven phthalate esters were: mono-n-methyl phthalate (MMP) was 99.89% (3 721/3 725); mono-ethyl phthalate (MEP) was 99.97% (3 724/3 725); mono-benzyl phthalate (MBzP) was 69.10% (2 574/3 725); mono-butyl phthalate (MBP), mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP) and mono- (2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) were 100.00% and mono-ethylhexyl phthalate (MEHP) was 99.95% (3 723/3 725). The median concentrations of the seven phthalate metabolites were: 17.71, 15.36, 0.07, 155.24, 10.73, 14.67, 3.59 µg/L, respectively. The median concentrations corrected by urinary creatinine were 29.65, 26.65, 0.12, 257.73, 17.94, 24.80, 6.27 µg/g Cr, respectively. The P(25) and P(7)5 concentration of the total PAEs metabolites corrected by urinary creatinine were 1.20 µmol/g Cr and 3.04 µmol/g Cr. After adjusted the relevant demographic information: children sex, children age in month, maternal age, parental education levels, household exposure to secondhand smoke and whether the child is the only child as confounds, multivariate logistic regression model showed that the risk of inhibitory self-control index (ISCI) dysplasia in MEHHP high concentration group and MEOHP high concentration group were 1.71 and 1.54 times (OR=1.71, 95% CI: 1.11-2.62; OR=1.54, 95% CI: 1.01-2.34) than in low concentration group. The risk of ISCI dysplasia in total PAEs metabolites high concentration group was 1.55 times (OR=1.55, 95% CI: 1.00-2.38) than in low concentration group. Conclusion: Phthalates exposure may damage the executive function of preschool children.

Effects of the phthalate exposure during three gestation periods on birth weight and their gender differences: A birth cohort study in China

Phthalate has been widely used as a type of plasticiser in various consuming products in daily life. Recent studies have suggested that prenatal phthalate exposure may have adverse effects on fetal development. We aimed to identify the effects of in utero phthalate exposure on birth weight (BW). We evaluated a birth cohort comprising 3474 pregnant women and their single infants; 3103, 2975 and 2838 urine samples were collected in the first, second and third trimesters, respectively. Phthalate metabolites included monomethyl phthalate (MMP), monoethyl phthalate (MEP), mono-n-butyl phthalate (MBP), monobenzyl phthalate (MBzP), mono-(2-ethylhexyl) phthalate (MEHP), mono-(2-ethyl-5-oxohexyl) phthalate (MEHHP), and mono-(2-ethyl-5-hydroxylhexyl) phthalate (MEOHP), which were analysed in the urine by using high performance liquid chromatography-tandem mass spectrometry. Mixed linear model was used in the statistical analysis. Generally, MMP and MEP exposure during pregnancy was associated with decreased birth weight of infants (MMP, β=-12.192, p=0.009; MEP, β=-11.876, p=0.014). Hierarchical analysis found that MMP and MEOHP exposure was associated with decreased infants' birth weight only in low birth weight groups (MMP, β=-42.538, p=0.005; MEOHP, β=-63.224, p=0.008); MEHP and MEHHP exposure was associated with decreased infants' birth weight in both low birth weight group (MEHP, β=-42.348, p=0.035; MEHHP, β=-50.485, p=0.006) and high birth weight group (MEHP, β=-16.580, p=0.034; MEHHP, β=-18.009, p=0.040), MBP and MEHP exposure were associated with increased infants' birth weight in male NBW group (MBP, β=10.438, p=0.039; MEHP, β=13.223, p=0.017). Moreover, the effect has sex difference. The reduction of birth weight associated with MEHP and MEOHP exposure was stronger in male infants, while MMP and MEP exposure was more significant in female infants.

Prenatal phthalate exposure and placental size and shape at birth: A birth cohort study

OBJECTIVE

There is concern over the potential placental effects of prenatal phthalate exposure, and the potential adverse effects of prenatal phthalate exposure require further study; however, few data are available in humans. We investigated the associations between phthalate exposure in each trimester and both placental size and shape at birth.

METHODS

We measured the urinary concentrations of phthalate metabolites among 2725 pregnant women in the Ma'anshan Birth Cohort. Before collecting urine samples from each of the three trimesters, the pregnant women were interviewed via questionnaires. Placental information was obtained from hospital records. We estimated the sex-specific associations between urinary phthalate concentrations in each trimester and both placental size and shape at birth using adjusted multiple regression. A linear mixed model was used for the repeated measures analysis with subject-specific random intercepts and slopes for gestational age at sample collection to test the effect of phthalate levels on placental size and shape and to estimate the effect sizes.

RESULTS

Overall, placental breadth increased by 0.148cm (95% CI: 0.078, 0.218) with each 1 ln-concentration increase in MBP in the first trimester. The difference between placental length and breadth (length-breadth) decreased by 0.086cm (95% CI: -0.159, -0.012) and 0.149cm (95% CI: -0.221, -0.076) with each 1 ln-concentration increase in MMP and MBP, respectively, in the first trimester. In the second trimester, placental thickness increased by 0.017cm (95% CI: 0.006, 0.027), 0.020cm (95% CI: 0.004, 0.036), 0.028cm (95% CI: 0.007, 0.048), and 0.035cm (95% CI: 0.018, 0.053) with each 1 ln-concentration increase in MMP, MBP, MEOHP, and MEHHP, respectively. In the third trimester, placental thickness increased by 0.037cm (95% CI: 0.019, 0.056) and 0.019cm (95% CI: 0, 0.037) with each 1 ln-concentration increase in MBP and MEHP, respectively. Multiple linear regression for each offspring sex indicated that prenatal phthalate exposure increased placental thickness in both the first and second trimesters in males, whereas the corresponding relationship was close to null in females. Linear mixed models (LMMs) yielded similar results.

CONCLUSION

Our results suggest the presence of associations between prenatal phthalate exposure and placental size and shape. Exposure to certain phthalates may cause the placenta to become thicker and more circular. Associations appeared stronger for the subsample representing male offspring than those for the subsample representing female offspring. Given the few studies on this topic, additional research is warranted.

[The effect of pre-pregnancy weight and the increase of gestational weight on fetal growth restriction: a cohort study]

Objective: To investigate the effect of pre-pregnancy weight and the increase of gestational weight on fetal growth restriction. Methods: From May 2013 to September 2014, a total of 3 474 pregnant women who took their first antenatal care and willing to undergo their prenatal care and delivery in Ma 'anshan Maternity and Child Care Centers were recruited in the cohort study. Excluding subjects without weight data before delivery (n=54), pregnancy termination (n=162), twins live births (n=39), without fetal birth weight data (n=7), 3 212 maternal-singleton pairs were enrolled for the final data analysis. Demographic information of pregnant woman, pregnancy history, disease history, height and weight were collected. In the 24(th)-28(th), 32(nd)-36(th) gestational week and childbirth, three follow-up visits were undertaken to collect data of pregnancy weight, pregnancy vomiting, gestational hypertension, gestational diabetes mellitus, newborn gender and birth weight. χ(2) test was used to compare the detection rate of fetal growth restriction in different groups. Multivariate unconditional logistic regression model and spreadsheet were used to analyze the independent and interaction effect of pre-pregnancy weight and the increase of gestational weight on fetal growth restriction. Results: The incidence of fetal growth restriction was 9.7%(311/3 212). The incidence of fetal growth restriction in pre-pregnancy underweight group was 14.9% (90/603), higher than that in normal pre-pregnancy weight group (8.7% (194/2 226)) (χ(2)=24.37, P<0.001). The incidence of fetal growth restriction in inadequate increase of gestational weight group was 17.9% (50/279), higher than the appropriate increase of weight group (11.8% (110/932)) (χ(2)=36.89, P<0.001). Multivariate unconditional logistic regression analysis showed that compared with normal pre-pregnancy weight group, pre-pregnancy underweightwas a risk factor for fetal growth restriction, with RR (95%CI) at 1.76 (1.34-2.32); Compared with the appropriate increase of gestational weight group, inadequate weight increase during pregnancy was a risk factor for fetal growth restriction, with the RR (95%CI) at 1.70 (1.17-2.48). No additive model interaction [relative excess risk of interaction, attributable proportions of interaction, the synergy index and their 95%CI were 0.75 (-2.14-3.63), 0.21 (-0.43-0.86) and 1.43 (0.45-4.53), respectively] or multiplication model interaction (RR (95%CI): 1.00 (0.44-2.29)) existed between pre-pregnancy underweight and inadequate increase of gestational weight on fetal growth restriction. Conclusion: Pre-pregnancy underweight and inadequate increase of gestational weight would increase the risk of fetal growth restriction without interaction.

[Early adiposity rebound: prevalence and the effect on metabolic risk in children]

The timing of the adiposity rebound (AR) gradually shifted to earlier ages throughout the world; early AR has a great effect on children's health, especially is possible associated with the development of metabolic disease for life, while the special mechanism isn't very clear. Metabolic diseases(MD) are common in adults, and the establishment of MD is the result of pathological chronic processes that can start in early life stages. If the metabolic risk factors and its predictive factors can be found in early childhood, it can bring forward the prevention and control of adult diseases. This paper is a review of the prevalence of early AR around the world, the factors that influence the timing of the AR, the significance of early detection and prevention of MD, the associations between timing of AR and metabolic risk in children and explored the possible mechanism. It aims to raise public awareness about the harm of early AR and provide new perspective to prevent and control of the metabolic syndrome.

[Dietary patterns among preschoolers and its association with education level of the parents]

Objective: To identify the dietary patterns among preschoolers in Ma'anshan, and to investigate its association with the education levels of the parents. Methods: A total of 16 439 children aged 3-6 were recruited from 91 kindergartens in Ma'anshan city to participate in the study. Food frequency and socio-demographic information were collected through questionnaire survey. Dietary data was collected using a food frequency questionnaire (FFQ), and principal-components analysis was used to derive the dietary patterns. Ordinal multinomial logistic regression was employed to explore the association between the education level of parents and the dietary patterns. Results: Five dietary patterns- "processed" , "beverage" , "snack" , "protein" and "vegetarian" were identified. Data showed that the total variance was 48.02% and the cumulative proportion of processed reached 24.78%. Low educational level of the father was positively associated with both "beverage" (OR=1.36, 95%CI: 1.15-1.63) and "snack" dietary pattern (OR=1.21, 95%CI: 1.01-1.43). Low educational level of mother was positively associated with the "processed" (OR=1.31, 95%CI: 1.09-1.57) and "beverage" dietary pattern (OR=1.48, 95%CI: 1.23-1.77), and showed a negative correlation with "protein" (OR=0.62, 95%CI: 0.52-0.74) and "vegetarian" dietary pattern (OR=0.72, 95%CI: 0.60-0.86). Conclusion: Findings from this study showed that preschoolers in Ma'anshan tend to choose unhealthy dietary pattern. Dietary pattern was directly influenced by the parents, and especially the education level of the mothers.

Urinary concentrations of phthalate metabolites in early pregnancy associated with clinical pregnancy loss in Chinese women

Limited evidence revealed conflicting results on relationship between phthalate exposure and clinical pregnancy loss (gestational weeks >6). A prospective cohort study in Chinese pregnant women (n = 3220) was conducted to investigate the association between urinary phthalate metabolites and clinical pregnancy loss (gestational weeks 6 to 27; n = 109). Morning urine samples during gestational weeks 5 to 14 (mean 10.42) were collected to measure monomethyl phthalate (MMP), monoethyl phthalate (MEP), monobutyl phthalate (MBP), monobenzyl phthalate (MBzP), mono (2-ethylhexyl) phthalate (MEHP), mono (2-ethyl-5-oxohexyl) phthalate (MEOHP) and mono (2-ethyl-5-hydroxyhexyl) phthalate (MEHHP). The concentrations of low- and high-molecular weight phthalate metabolites (ΣLMWP <250 Da and ΣHMWP >250 Da) were calculated. Adjusted logistic regression models showed increased risks of clinical pregnancy loss in women with higher creatinine- normalized concentrations of MEP, MBP, MEOHP, MEHHP, ΣLMWP and ΣHMWP. Stratified analysis by gestational weeks (10 weeks) of miscarriage indicated positive associations of MEP, MEOHP, MEHHP and ΣHMWP with embryonic loss (during gestational weeks 6 to 10). The only association of foetal loss (during gestational weeks 11 to 27) was observed with MEHHP. Our findings suggested that Chinese women who were exposed to phthalates during early pregnancy had an increased risk of clinical pregnancy loss, especially embryonic loss.

Cumulative risk assessment of phthalates associated with birth outcomes in pregnant Chinese women: A prospective cohort study

A prospective cohort study of a Chinese population of mother-neonate pairs (n = 3103) was conducted to investigate the relationship between the cumulative hazard index (HI) of combined diethyl phthalate (DEP), dibutyl phthalate (DBP), dibenzyl phthalate (BBzP) and di(2-ethylhexyl) phthalate (DEHP) exposure and birth outcomes. The estimated HI for phthalates was based on phthalate metabolite concentrations in urine collected between 5th and 14th gestational weeks. The median HI values according to the European Food Safety Authority tolerable daily intake (HI_TDI) and U.S. Environmental Protection Agency reference dose (HI_RfD) were 0.358 and 0.187, respectively. A total of 16.3% and 1.9% of the women exhibited HI_TDI and HI_RfD exceeding the value of one, respectively. In unadjusted models, the categories (low < P₂₅, median P₂₅-P₅₀, high > P₇₅) of HI_TDI were associated with decreased birth weight (β = -26.34 g, p = 0.021) and head circumference (β = -0.09 cm, p = 0.029), whereas those for HI_RfD were negatively associated with birth weight (β = -31.74 g, p = 0.005), birth length (β = -0.11 cm, p = 0.032), head circumference (β = -0.13 cm, p = 0.003) and chest circumference (β = -0.10 cm, p = 0.021) in all neonates. Adjustment for potential confounders revealed that HI_RfD was inversely associated with head circumference (β = -0.10 cm, p = 0.020). Stratification by gender indicated that HI_RfD was associated with decreased birth length (β = -0.17 cm, p = 0.041) in infant boys and HI_TDI was associated with decreased birth weight (β = -33.12 g, p = 0.036) and head circumference (β = -0.13 cm, p = 0.027) in girls. This is the first study on the cumulative risk assessment of phthalate exposures in pregnant Chinese women. We found that the HI values of multiple phthalate co-exposure were sex-specifically related to birth outcomes.

[Previous medical or surgical abortions and subsequent risk of preterm birth: a birth cohort study]

Objective: To understand the association between medical abortion (MA) or surgical abortion (SA) and the risk of preterm birth (PTB) in subsequent pregnancy. Methods: The prospective cohort study was conducted in Ma'anshan, Anhui province. The information about demographic characteristics and previous MA or SA of 3 474 pregnant women were collected before 14 gestational weeks. Logistic regression analysis was conducted to compare the rates of preterm birth based on the history of previous MA or SA, and 3 256 live births were included in the analysis. Results: The PTB rate and spontaneous preterm birth (sPTB) rate were 4.12% (n=134) and 2.49% (n=81) respectively. Previous MA was associated with an increased risk of total PTB (RR=2.00, 95%CI: 1.04-3.85 for one MA and RR=3.58, 95%CI: 1.04-12.30 for two or more MAs) and sPTB (RR=2.51, 95% CI: 1.23-5.15). The risk of PTB in women with one SA (RR=0.67, 95%CI: 0.42-1.01) or more SA (RR=0.97, 95%CI: 0.51-1.85) did not differ significantly compared with the women with no history of SA. Conclusion: This study suggests that medical abortion could increase the risk of PTB or sPTB.

Longitudinal pattern of early maturation on morning cortisol and depressive symptoms: Sex-specific effects

There is still insufficient understanding of the underlying processes that contribute to internalizing problems of early maturing adolescents. The purpose of this study is to examine the longitudinal pattern of early maturation and its effects on morning cortisol and depressive symptoms among a general population of adolescent cohort aged 8-11 years old at baseline (boys=424, girls=288). Results suggest newly-onset early maturation boys have 3-times more likely to have depressive symptoms at 1-year follow-up (adjusted odds ratio=3.197, 95% confidence interval=1.595-6.405); while in girls, stable early maturation individuals are more than 4 times as likely to have depressive symptoms (adjusted odds ratio=4.566, 95% confidence interval=1.882-11.077). Morning cortisol has moderating effects in the association of depressive symptoms with newly-onset early maturation in boys and stable early maturation in girls. These findings possibly explain current inconsistent results regarding association between earlier maturation and risk of depression in adolescents. Further longitudinal studies are needed to explore HPG-HPA interactions in adolescence, which may be critical to understanding the heightened susceptibility of mental health problems.

Maternal phthalate exposure during the first trimester and serum thyroid hormones in pregnant women and their newborns

Animal and human studies have suggested that phthalate alters thyroid hormone concentrations. This study investigated the associations between phthalate exposure during the first trimester and thyroid hormones in pregnant women and their newborns. Pregnant women were enrolled from the prospective Ma'anshan Birth Cohort study in China. A standard questionnaire was completed by the women at the first antenatal visit. Seven phthalate metabolites were measured in one-spot urine at enrolment (10.0 ± 2.1 gestational weeks), as were thyroid hormone levels in maternal and cord sera. Multivariable linear regression showed that 1-standard deviation (SD) increase in natural log (ln)-transformed mono(2-ethylhexyl) phthalate (MEHP) and mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) was associated with 0.163 μg/dL (p = 0.001) and 0.173 μg/dL (p = 0.001) decreases in maternal total thyroxine (TT4). Both MEHP and MEHHP were negatively associated with maternal free thyroxine (FT4; β: -0.013, p < 0.001 and β: -0.011, p = 0.001, respectively) and positively associated with maternal thyroid-stimulating hormone (β: 0.101, p < 0.001; β: 0.132, p < 0.001, respectively). An inverse association was observed between monobenzyl phthalate and maternal TT4 and FT4. A 1-SD increase in ln-transformed monoethyl phthalate was inversely associated with maternal TT4 (β: -0.151, p = 0.002). By contrast, the concentrations of phthalate metabolites in urine were not associated with those of thyroid hormone in cord serum. Our analysis suggested that phthalate exposure during the first trimester disrupts maternal thyroid hormone levels.

[Intrahepatic cholestasis of pregnancy and fetal outcomes: a prospective birth cohort study]

OBJECTIVE

To evaluate the relations between the second and third trimesters intrahepatic cholestasis of pregnancy (ICP) and the fetal outcomes, in order to provide medical advice for early detection and intervention on ICP.

METHODS

A prospective cohort study was conducted in Ma' anshan, Anhui, China (Ma'anshan Birth Cohort, MABC). Pregnant women within 14 weeks of gestation were consecutively recruited when standards were met. Anthropometrics were collected in early pregnancy. Maternal serum total bile acid level (TBA) was collected in the second and third trimesters, and women were viewed as cases if the results were accorded with clinical diagnosis. Logistic regressions were conducted to examine the associations of the second and third trimester ICP, and fetal outcomes.

RESULTS

A total of 2 978 pregnant women were included in this study. The rate of ICP was 6.5% (n=196), and the rates of the second and third trimesters were 1.4% (n=43) and 5.1% (n=153) respectively. After controlling for potential confounders, we found that ICP from both the second and third trimesters could increase the risks of preterm birth, low birth weight (LBW), fetal distress and meconium-stained amniotic fluid.OR values (95% CI) were 6.42 (2.59-15.93) and 3.73 (2.07-6.72) for preterm birth while 6.52 (2.19-19.45) and 4.90 (2.43-9.90) for LBW, 2.91 (1.27-6.67) and 1.88 (1.11-3.19) for fetal distress and 2.34 (1.19-4.61) and 1.66 (1.11-2.48) for meconium-stained amniotic fluids, respectively. The risk of adverse fetal outcomes caused by the second trimester ICP appeared significantly higher than the third trimester ICP.

CONCLUSION

ICP from the second and third trimesters significantly increased the risk of adverse fetal outcomes, suggesting that clinicians should put more attention to the second trimester ICP. Both early detection and intervention were of great importance in reducing the adverse fetal outcomes.

De novo assembly and characterization of farmed blue fox (Alopex lagopus) global transcriptome using Illumina paired-end sequencing

The blue fox (Alopex lagopus), a coat-color variant of the Arctic fox, is a domesticated fur-bearing mammal. In the present study, transcriptome data generated from a pool of nine different tissues were obtained with Illumina HiSeq2500 paired-end sequencing technology. After filtering from raw reads, 32,358,290 clean reads were assembled into 161,269 transcripts and 97,252 unigenes by the Trinity fragment assembly software. Of the assembled unigenes, 37,967 were annotated in the National Center for Biotechnology Information (NCBI) Non-Redundant (NR) protein database and 26,264 in the Swiss-Prot database. Among the annotated unigenes, 24,839 and 24,267 were assigned using the Gene Ontology (GO) and euKaryotic Orthologous Groups (KOG) databases, respectively. Altogether, 17,057 unigenes were mapped onto 227 pathways using the Kyoto Encyclopedia of Genes and Genomes database. In addition, 6394 simple sequence repeats were identified by examining 12,965 unigenes (>1 kb), which could contribute to the development of molecular markers. This study generated transcriptome data for the blue fox that will promote further progress in expression profiling studies, and provide a good annotation basis for genomic studies.

Identification of polymorphisms and transcriptional activity of the proto-oncogene KIT located on both autosomal and B chromosomes of the Chinese raccoon dog

B chromosomes are dispensable and co-exist with autosomal and sex chromosomes. The karyotype of the Chinese raccoon dog (Nyctereutes procyonoides procyonoides) comprises 0-4 B chromosomes. The proto-oncogene KIT is found on all B chromosomes of the Chinese raccoon dog. In the present study, partial DNA and mRNA sequences of KIT were amplified and sequenced from four individuals containing B chromosomes. Sequence analyses revealed that polymorphisms including single nucleotide polymorphisms (SNPs) and inserts/deletions were rich in the KIT gene of Chinese raccoon dog at the genomic level. However, no polymorphism was detected at the mRNA level. A comparison of mRNA sequences from Chinese raccoon dogs with the corresponding sequences derived from arctic fox and dog, which do not contain B chromosomes, revealed the mRNA sequences of the 10 SNPs to be identical between these three species. Therefore, these findings suggest that KIT located on the B chromosomes in Chinese raccoon dog lacks transcriptional activity.

Identification of cDNA sequences and alternative splicing patterns of canine AMEL genes (AMELX and AMELY)

Amelogenin is a major protein of the developing enamel matrix. There are two amelogenin genes (AMELX and AMELY) located on the X and Y chromosomes, respectively, in dogs. In the present study, we characterized full-length cDNAs and alternative splicing patterns of the AMEL genes in the tooth tissue of a dog by 5'- and 3'-rapid amplification of cDNA ends and AMEL-specific RT-PCR. Sequence analysis revealed that the coding regions of AMELX and AMELY were 579 and 576 bp (accession Nos. KP244310 and KP244311), respectively. The coding sequence of AMELX had 95.1% identity to that of AMELY. The AMEL genes on X and Y chromosomes were both expressed in developing tooth tissue. Eight different alternatively spliced transcripts were identified, five from AMELX and three from AMELY.

Cloning and identification of the ASIP gene in Chinese raccoon dog (Nyctereutes procyonoides procyonoides)

The quantity, quality, and distribution of eumelanin and pheomelanin determine a wide variety of coat colors in animals. Three coat color variants exist in farmed wild-type Chinese raccoon dog (Nyctereutes procyonoides procyonoides), which is an important fur-bearing animal species. The ASIP gene is an important candidate gene for coat color variation in some species. In this study, the complete cDNA sequences of ASIP were amplified from a wild-type Chinese raccoon dog. Sequence analysis revealed the coding region of ASIP in Chinese raccoon dog to be 396-bp in length and two transcripts (accession Nos. KT224450 and KT224451) were identified due to the alternative use of exon 1 (1A and 1C). However, the alternative splicing pattern and the coding sequence of ASIP in three types of coat color variants were the same as those identified in the wild-type individual. Based on the results obtained in this study, we can exclude a role for alternative splicing of exon 1 and the coding sequence of ASIP in coat color variation in Chinese raccoon dog.

Cloning and association analysis of KIT and EDNRB polymorphisms with dominant white coat color in the Chinese raccoon dog (Nyctereutes procyonoides procyonoides)

The Chinese raccoon dog (Nyctereutes procyonoides procyonoides) is one of the most important fur-bearing animal species. The dominant white individual, a coat color variant in farmed Chinese raccoon dog, shows a completely white phenotype over the entire body. The KIT and EDNRB genes have been reported to be associated with the dominant white coat color in some mammalian species. In the present study, the full-length coding sequences of KIT and EDNRB were amplified from a dominant white and a wild-type Chinese raccoon dog. Sequence analysis revealed that the coding region of KIT and EDNRB in Chinese raccoon dog was 2919 and 1332 base pairs in length (accession No. KM083121 and KM083122), respectively, and 2 single-nucleotide polymorphisms (SNPs; c.600C>T and c.967G>A) in KIT and 1 SNP (c.259A>C) in EDNRB was found only in the dominant white individual. An alternative splicing site at the boundary of 4 and 5 of the KIT gene was identified in both individuals. We further investigated the association between the 3 SNPs of KIT and EDNRB and dominant white coat color by genotyping 18 individuals. We found no association between these SNPs and dominant white coat color. Based on these results, we can exclude the coding regions of the KIT and EDNRB genes as determinants of the dominant white coat color in Chinese raccoon dog.

Maternal thyroid function in the first twenty weeks of pregnancy and subsequent fetal and infant development: a prospective population-based cohort study in China

CONTEXT

There are a few prospective population-based cohort studies evaluating the effects of maternal thyroid dysfunctions on fetal and infant developments, but they are inconsistent.

OBJECTIVE

The objective of the study was to investigate the effects of maternal thyroid dysfunction on fetal and infant development.

SETTING AND PARTICIPANTS

The study was nested within a prospective population-based China-Anhui Birth Defects and Child Development study. A total of 1017 women with singleton pregnancies participated in this study. Maternal serum samples in the first 20 wk of pregnancy were tested for thyroid hormones (TSH and free T(4)). Pregnant women were classified by hormone status into percentile categories based on laboratory assay and were compared accordingly.

MAIN OUTCOMES

Outcomes included fetal loss, malformation, birth weight, preterm delivery, fetal stress, neonatal death, and infant development.

RESULTS

Clinical hypothyroidism was associated with increased fetal loss, low birth weight, and congenital circulation system malformations; the adjusted odds ratios [95% confidence interval (CI)] were 13.45 (2.54-71.20), 9.05 (1.01-80.90), and 10.44 (1.15-94.62), respectively. Subclinical hypothyroidism was associated with increased fetal distress, preterm delivery, poor vision development, and neurodevelopmental delay; the adjusted odds ratios (95% CI) were 3.65 (1.44-9.26), 3.32 (1.22-9.05), 5.34 (1.09-26.16), and 10.49 (1.01-119.19), respectively. Isolated hypothyroxinemia was related to fetal distress, small for gestational age, and musculoskeletal malformations; the adjusted odds ratios (95% CI) were 2.95 (1.08-8.05), 3.55 (1.01-12.83), and 9.12 (1.67-49.70), respectively. Isolated hyperthyroxinemia was associated with spontaneous abortion; the adjusted odds ratio (95% CI) was 6.02 (1.25-28.96). Clinical hyperthyroidism was associated with hearing dysplasia; the adjusted odds ratio (95% CI) was 12.14 (1.22-120.70).

CONCLUSIONS

Thyroid dysfunction in the first 20 wk of pregnancy may result in fetal loss and dysplasia and some congenital malformations.