Dose-response relationship between maternal thyroid hormones in the first twenty weeks and physical and neuropsychological development of infants: A prospective cohort study in China / 中华流行病学杂志

Objective: To study the dose-response relationship between maternal thyroid hormone levels in the first twenty weeks of pregnancy and the infant physical and neuropsychological development. Methods: In this prospective cohort study, a total of 945 women and their children were included. Maternal serum samples during first half of the pregnancy were collected and analyzed for levels of thyroid hormones by using the electro-chemiluminescence immunoassay. Maternal social demographic information was collected by using the a self-administered questionnaire. Physical measurements of newborns and neuropsychological evaluation of infants were performed by doctors of maternal and child health care. Results: The differences in newborns' birth length and head circumference were significant among the newborns of mothers with different percentiles of maternal serum (thyroid-stimulating hormone, TSH) levels (P<0.05). Newborns with maternal TSH level ≥P(95) or <P(5) had significantly lower birth length and birth head circumference, compared with the newborns with maternal TSH level between P(25)-P(75) (P<0.05). Newborns' birth head circumferences showed an inverted U-shaped association with maternal serum TSH level (Y=33.940+0.003X-0.109X(2), F=4.685, P=0.009). The difference in mental development index (MDI) of the infants at 18-30 months were significant among the infants of mothers with different percentiles of maternal serum TSH level (P<0.05). Infants with maternal TSH level ≥P(90) showed lower MDI (6.39, 95%CI: 2.29-10.49, P=0.002) compared with the infants with maternal TSH level between P(25)-P(75). Infant's MDI at 18- 30 months also showed an inverted U-shaped association with maternal serum TSH level (Y=103.249-1.524X-0.939X(2), F=6.616, P=0.001). Conclusions: Maternal TSH level was associated with newborn's birth length, birth head circumference and infant's MDI at 18-30 months. Newborn's birth head circumference and infant's MDI at 18-30 months showed an inverted U-shaped association with maternal serum TSH-Z score.

Exposure to bisphenol A during maternal pregnancy and the emotional and behavioral impact on their preschool children / 中华流行病学杂志

Objective: To explore the long-term effects of maternal pregnancy bisphenol A (BPA) exposure on emotional and behavioral problems appeared in their preschool children. Methods: The study sample was a subset of the China-Anhui Birth Cohort Study (C-ABCS). A unified questionnaire was used to collect basic information on both pregnant women and their children. Free BPA concentration in maternal serum was determined by high-performance liquid chromatographytandem mass spectrometry (HPLC-MS/MS). The parent-report version of the Strengths and Difficulties Questionnaire (SDQ) was used to estimate the emotional and behavioral problems in preschool children. A total of 1 713 pairs of mothers and children were included in this study. Association between BPA exposure during pregnancy and the emotional and behavioral problems in preschool children was evaluated with multinomial logistic regression model. Results: Prevalence rates in 1 713 preschool children appeared as: 6.48% of emotional problems, 8.11% for conduct problems, 8.35% for hyperactivity/inattention, 2.86% for peer problems, 11.38% for prosocial behaviors and 7.94% for total difficulties. Subjects were divided according to the degrees of exposure and the results showed as: low exposure group (≤0.120 ng/ml), medium exposure group (0.120<BPA<0.400 ng/ml) and high exposure group (≥0.400 ng/ml) according to the serum BPA concentration in tertile. Results from the multivariate logistic regression analysis showed that high level of maternal BPA exposure appeared a risk factor on children's abnormal conducts (OR=1.876, 95% CI: 1.161-3.029), more obvious in boys (OR=2.291, 95%CI: 1.126-4.661). Conclusion: Maternal exposure to high level of BPA during pregnancy might increase the detrimental effects of abnormal conducts in their preschool children, more obviously seen in boys.

Potential interaction effect on attention-deficit/hyperactivity disorder between mother's educational level and preschoolers' dietary pattern / 中华流行病学杂志

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 pregnancy-related anxiety of pregnant women and autism-like behavior in their offspring at 18 months of age / 中华流行病学杂志

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.

Developmental characteristics of circadian rhythms in hypothalamic-pituitary-adrenal axis during puberty / 中华流行病学杂志

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.

Study on the relationship of thallium exposure and outcomes of births / 中华流行病学杂志

Objective: To investigate the relationship of thallium exposure and outcomes of births. Methods: A total of 3 236 mothers who had visited in Ma'anshan Maternal and Child Health-Care Hospital between May 2013 and September 2014 were included in this study and their thallium concentrations measured from samples of maternal and umbilical cord blood by inductively coupled plasma mass spectrometry. The results were correlated and evaluated with birth outcomes of the infants, using the multiple linear regression method. Results: The median (P(25)-P(75)) of thallium levels in first trimester, second trimester and umbilical cord blood were 61.7 (50.8-77.0), 60.3 (50.8-75.2) and 38.5 (33.6-44.1) ng/L, respectively. After adjustment for potential confounders, the thallium levels showed an inversely significant association with birth head circumference (unstandardized β coefficient=-0.41, 95%CI: -0.76- -0.06) in the first trimester blood, and associated with reduced birth length (unstandardized β coefficient=-0.65, 95%CI: -1.25- -0.05) in umbilical cord blood. However, there appeared no significantly associations with birth weight, length and head circumference (P>0.05) in second trimester. On stratification by sex, in girls but not in boys, the thallium levels were adversely associated with birth head circumference (unstandardized β coefficient=-0.53, 95%CI: -1.05--0.01) in the first trimester and were associated with decreased birth weight (unstandardized β coefficient=-277.08, 95%CI: -485.13- -69.03) and length (unstandardized β coefficient=-1.39, 95%CI: -2.26- -0.53) in umbilical cord blood thallium. Conclusions: Thallium exposure appeared a gender difference in newborn birth outcomes. In the first trimester, it was negatively associated with the birth head circumference, in the umbilical cord blood, and reduced birth weight and length in girls.

Pregnancy-related anxiety associated with small-for-gestational-age infants / 中华流行病学杂志

Objective: To investigate the second or third trimester pregnancy-related anxiety on small-for-gestational-age infants. Methods: This study was based on Ma'anshan Birth Cohort Study (MABC), with 3 040 maternal-singleton pairs finally selected for data analysis, from May 2013 to September 2014. The psychological state of pregnancy was evaluated according to a self-developed 'anxiety scale for gestation'. Small-for-gestational-age was defined as 'having birth weight below the 10(th) percentile at a particular gestational week', while large-for-gestational-age infants was defined as 'having birth weight above the 90(th) percentile'. Birth weight between the 10(th) and 90(th) percentile was classified as appropriate-for-gestational age infants. χ(2) test was used to compare the distribution of characteristics in pregnancy among three groups with different birth weights. Multivariate logistic regression models were conducted to evaluate the associations between third trimester pregnancy- related anxiety and birth weight. Results: The incidence rates of small- and large-gestational-age infants were 9.6% and 16.6%, respectively. Difference between women with only one of the second or third trimester pregnancy-related anxiety syndromes and small-for-gestational-age infants showed no statistical significance. Women with both second and third trimester pregnancy-related anxieties might increase the risk of small-for-gestational-age infants (OR=1.39, 95%CI: 1.04-1.87). However, there was no significant difference between pregnancy-related anxiety and large-for- gestational-age infants (OR=1.05, 95%CI: 0.81-1.35) noticed. Conclusion: Women with second and third trimester pregnancy-related anxiety appeared a risk factor for small-for-gestational-age infants.

Interactive effects between health literacy and mobile phone dependence as well as its relation with unintentional injuries in middle school students / 中华流行病学杂志

Objective: To investigate the interaction between health literacy, mobile phone dependence and unintentional injuries in middle school students, and to provide guidance for prevention on unintentional injuries in adolescents. Methods: From November 2015 to January 2016, a questionnaire survey was conducted among 22 628 middle school students in Shenyang of Liaoning province, Bengbu of Anhui province, Xinxiang of Henan province, Ulanqab of Inner Mongolia Autonomous Region, Chongqing and Yangjiang of Guangdong province. Chinese Adolescent Interactive Health Literacy Questionnaire (CAIHLQ), Self-rating Questionnaire for Adolescent Problematic Mobile Phone Use (SQAPMPU), and Unintentional Injuries Assessment Scale and demographic variables were used to measure the health literacy, mobile phone dependence and unintentional injuries among the Chinese middle school students. Results: The detection rates of mobile phone dependence and unintentional injuries were 25.4% and 46.7%, respectively. The rates of unintentional injuries of middle school students with mobile phone dependence and with low, medium and high health literacy were 53.6%, 44.4% and 48.8%, 48.1%, 41.7%. Factors as mobile phone dependence, low and middle health literacy were positively related to unintentional injuries (OR=1.452, 1.196, 1.364). However, the multiplicative interaction between mobile phone dependence and health literacy on unintentional injuries was noticed significant (OR=1.217, 95%CI: 1.041-1.422). Conclusions: Our results showed that the prevalence of unintentional injuries was relatively high in middle school students. Health literacy and mobile phone dependence seemed related to unintentional injuries. Interaction between health literacy and mobile phone dependence on unintentional injuries appeared significant.