OBJECTIVEThe term "premature thelarche" refers to isolated breast development before 8 years of age in female, without any other signs of sexual maturation, while "gynecomastia" is the presence of breast tissue in males. This study aimed to investigate the prevalence of premature thelarche and gynecomastia in Chinese infants and toddlers, identify the potential risk factors, and explore the influence of early breast development on physical growth, mental development and psychomotor development.

METHODA total of 1 510 full term and healthy children at the age of 0-48 months were sampled by stratified cluster random sampling method from 8 provinces from 2011-2012. Weight, height and breast development were assessed by senior primary pediatricians, while Bayley Scale of Infant Development-I (BSID-I) was used to measure the mental developmental index (MDI) and psychomotor developmental index (PDI) for children aged 2-30 months. Social-demographic Questionnaires were completed by the caregivers.

RESULTThe combined prevalence of premature thelarche and gynecomastia was 1.6% (23/1 475), girls 2.2% (15/695), boys 1.0% (8/780), all within 2 years of age. The birth weight, feeding patterns in first 4 months, delivery mode, weaning time and social economic status were not significantly associated with the breast development. However, lower father's education level (OR = 3.632, 95%CI = 1.565-8.432) as well as smoking mother (OR = 18.960, 95%CI = 1.590-226.304) were significantly related to breast development even after adjusting for potential confounders. Lower weight (-0.479 ± 0.648 vs. 0.005 ± 0.987, P < 0.05) and height (-0.602 ± 1.042 vs. 0.008 ± 0.986, P < 0.05) Z score were found in breast development group, even after adjusting for age, gender and father' education level. Neither mental development (t = -0.082, P > 0.05) nor psychomotor development (t = 1.054, P > 0.05) was associated with breast development.

CONCLUSIONWe showed a similar prevalence of premature thelarche with the data reported in similar studies reported from other countries. Among the 0-48 months old infants and toddlers, Father's education level and smoking mother were both related to breast development. Breast development was significantly associated with physical growth, but had no correlation with the mental or psychomotor development.

African Continental Ancestry Group ; Body Height ; Body Weight ; Breast ; growth & development ; Child Development ; Child, Preschool ; Cross-Sectional Studies ; Environmental Exposure ; Female ; Gynecomastia ; epidemiology ; etiology ; Humans ; Infant ; Infant, Newborn ; Male ; Multivariate Analysis ; Prevalence ; Puberty, Precocious ; epidemiology ; etiology

OBJECTIVETo explore the current television viewing situation among children less than 4 years of age in our country and investigate effects of television viewing on sleep quality.

METHODAccording to the"Hospital of Province-City-County"sampling technical route, a total of 1 046 full term healthy children at the age of 4-48 months were sampled by stratified cluster random sampling method from 8 provinces in China from 2012-2013. The information of television viewing and family and personal information was investigated by Shanghai Children's Medical Center Socio-demographic Questionnaire. Brief Infant Sleep Questionnaire (BISQ) and Brief Child Sleep Questionnaire (BCSQ) were employed to assess the sleep behaviors of children 0-3 years old and over 3 years old respectively.The effects of television viewing on sleep quality were analyzed by multiple linear regression analysis.

RESULTThe children's average age was (20±13) months, with boys accounted for 53.3% (558/1 046). The percentage of children who viewed television was 70.3% (735/1 046). Moreover, 58.7% (408/695) of infants and young children under the age of 2 viewed TV per day, and 19.9% (70/351) of 2 years and older infants and young children viewed television ≥2 hours per day. With the increase of age, the percentage of children who viewed television time gradually increased (P<0.001). Child sex, geographic area, paternal education, and family structure were not associated with television viewing time among children aged 4-48 months. However, the presence of a bedroom TV(χ(2)=13.682, P=0.001) and maternal employment (χ(2)=15.053, P=0.005) were commonly correlated with long screen-watching time among children. After adjusting for age, gender, mother' education level, and working state, it was revealed by multiple linear regression analysis that television viewing was not only positively correlated with later bedtime (t=5.49, P<0.001) and shorter night sleep duration (t=-3.49, P=0.001) but also significantly associated with longer sleep onset latency (t=2.63, P=0.009).

CONCLUSIONThe percentage of children under 4 years of age who viewed television is very high in our country, and many infants under 6 months of age exposed to TV environment. Bedroom TV and mother full-time job were associated with higher proportion of children viewing TV. In early childhood, television viewing was positively correlated with later bedtime, shorter sleep duration and longer sleep onset latency. There is a need for parents and pediatricians to pay more attention to the behavior of children viewing TV and improve sleep quality.

Child, Preschool ; China ; Family ; Female ; Humans ; Infant ; Male ; Parents ; Sleep ; Surveys and Questionnaires ; Television ; Time Factors