Evidence suggests that excessive screen time in early childhood is related to children’s physical and mental health. This study aimed to review the relationships between screen media use and several health indicators in infants, toddlers, and preschoolers. A systematic search was conducted by two independent reviewers on PubMed, Web of Science, Embase, and Cochrane Library to identify the eligible studies, with an end date of 13 August 2019. Included studies (published in English) were peer-reviewed and met the determinate population (children aged 0–7 years with screen media exposure and related health outcomes). The AHRQ, NOS, and the Cochrane Handbook were used to evaluate the cross-sectional study, cohort study, and RCT, respectively. A meta-analysis and narrative syntheses were employed separately. Eighty studies (23 studies for meta-analysis) met the inclusion criteria for the systematic review. Strong evidence of the meta-analysis suggested that excessive screen time was associated with overweight/obesity and shorter sleep duration among toddlers and preschoolers. Excessive screen use was associated with various health indicators in physical, behavioral, and psychosocial aspects. Better-quality research on newer media devices, on various kinds of contents in young children, and on dose–response relationships between excessive screen use and health indicators are needed to update recommendations of screen use.

Depressive symptoms are a common mental health problem among adolescents, which may affect their physical and mental health development and impose heavy burdens on individual families and society. This study aimed to examine the associations between sleep duration, academic pressure, and depressive symptoms among Chinese adolescents and to construct the mediation model to explore the mediating effect of sleep duration. The data are from the China Family Panel Studies (CFPS). Methodologically, the aforementioned associations were explored by constructing a structural equation model and applying multivariate multilevel logistic regression. In this study, we found that approximately 6.49% of the 3724 Chinese adolescents had depressive symptoms. Sleep duration of <6 h/night (OR = 2.39, 95%CI = 1.33–4.32) and high/maximum academic pressure (high: OR = 1.43, 95%CI = 1.02–1.99; maximum: OR = 2.43, 95%CI = 1.58–3.73) were both associated with an increased risk of depressive symptoms in adolescents. Meanwhile, the multiplicative interaction between sleep duration and academic pressure was significantly associated with depressive symptoms in adolescents (p < 0.001). The sleep duration played a partial mediating role in the relationship between academic pressure and depressive symptoms (a*b = 0.006, 95%BootCI = 0.001–0.012). Our study highlights that it is essential to mitigate the academic pressure of adolescents to increase their sleep duration and further reduce the occurrence of depressive symptoms by adopting corresponding preventive measures.

This study aimed to examine the associations between the duration of folic acid (FA) supplementation, gestational diabetes mellitus (GDM), and adverse birth outcomes. A total of 950 mother-offspring pairs participated in the cohort study during 2015 in Changsha, China. The data were collected through home visits and perfected by maternal and child healthcare handbooks. Generalized linear models and stratified analyses were used for statistical analyses. The incidence of GDM in our cohort was 10.2%. FA supplementation for ≥3 months before pregnancy was associated with an increased risk of GDM (adjusted relative risk (aRR): 1.72; 95% CI: 1.17–2.53) and decreased risk of small-for-gestational-age (SGA) birth (aRR: 0.40; 95% CI: 0.18–0.88). In the group of FA supplementation for ≥3 months during pregnancy, GDM was associated with an increased risk of cesarean delivery (aRR: 1.36; 95% CI: 1.06–1.75) and macrosomia (aRR: 2.11; 95% CI: 1.06, 4.20), but the aRRs were lower than the RR_MH 1.53 (95% CI: 1.01–2.34) and 2.43 (95% CI: 1.27–4.66). Our study suggested that the longer duration of FA supplementation before pregnancy might increase the risk of GDM, but decrease the risk of SGA birth. Longer duration of FA supplementation during pregnancy had beneficial effects on birth outcomes in women with GDM. Further studies should consider a larger sample size to confirm these findings.

Background: There is not much data on the effects of the timing of gestational weight gain (GWG), pre-pregnancy waist circumference (WC), pre-pregnancy body mass index (BMI), and parity, with postpartum weight retention (PPWR) trajectories. Methods: This study was based on a longitudinal cohort. Latent growth mixture models were applied to identify the latent trajectories of PPWR and test the effects of the predictors on distinct classes of PPWR trajectories. Results: Three PPWR trajectories were identified. About 2.8% (n = 26) of women were classified into Class 1, with an inverted U-shape trajectory; 6.6% (n = 61) were assigned to Class 2, with a rapid increase trajectory; 90.6% (n = 837) were classified into Class 3, with a significant decrease. Women who had a lower pre-pregnancy BMI (β = −0.279), higher pre-pregnancy WC (β = 0.111) and GWG (β = 0.723) were at a higher risk of retaining more weight at 1 month postpartum. Only GWG, especially GWG during late pregnancy, was associated with the rate of PPWR change. Parity was not associated with the changes in PPWR, while, compared to Class 1 trajectory, multiparous women were protected from having a Class 2 trajectory. Conclusions: Early targeted interventions should be taken to prevent women who were primiparous, and/or had a lower pre-pregnancy BMI and higher pre-pregnancy WC and GWG, from excessive PPWR.

Background: The association of maternal parity, pre-pregnancy body mass index (BMI) and gestational weight gain (GWG) with childhood weight status has been well studied; however, little is known about these factors with respect to the rate of weight changes in early childhood. Methods: This study was based on a prospective longitudinal study. The follow-up surveys were conducted at the ages of 1, 3, 6, 8, 12, and 18 months. Child weight was investigated twice at each wave. Data on maternal parity, pre-pregnancy weight and height were collected at baseline. The latent growth curve model was used to examine the effects of interested predictors on the trajectory of weight in early childhood. Results: Finally, 893 eligible mother-child pairs were drawn from the cohort. In adjusted models, multiparas were associated with higher birth weight (β = 0.103) and slower weight change rate of children (β = −0.028). Pre-conception BMI (β = 0.034) and GWG (β = 0.014) played important roles in the initial status of child weight but did not have effects on the rate of weight changes of the child. Conclusions: Multiparous pregnancy is associated with both higher mean birth weight and slower weight-growth velocity in early childhood, while pregravid maternal BMI and GWG are only related to the birth weight.

Environmental exposures, especially parenting quality, are critical for later child development. This study aimed to determine the status of parenting quality and suspected development delay of preschool children in China’s urban area and explore the associations between these two factors. The research was based on a birth cohort study conducted in Changsha, Hunan province, China. We used the Parenting Assessment Tool and Ages and Stages Questionnaires, Third Edition (ASQ-3), to measure parenting quality and child development status, respectively. Other data were collected from maternal health manuals and self-administered questionnaires during the follow-up period. The generalized estimating equation was used to examine whether parenting quality was significantly associated with child development outcomes. In the study, good parenting quality was 33.6% measured at 18 months, and suspected development delay was below 10% at 36–48 months among urban China; we observed negative associations between parenting quality scores and child development scores; poor parenting quality had a negative association with suspected development delay [OR and 95% CI: 2.74 (1.17, 6.40)], girls [OR and 95% CI: 0.33 (0.16, 0.69)] and maternal education years (>12 years) [OR and 95% CI: 0.27 (0.12, 0.64)] were protective factors for suspected development delay. Our findings highlighted the importance of good parenting quality among children in urban areas of China through a birth cohort study and may be used to reduce the children at high risk of developmental delay as a future intervention program.