OBJECTIVETo understand prevalence of sleep problems and presence of improper sleep habit of children aged one to 23 months in Shanghai, and to identify their related factors.

METHODSTotally, 1 252 normal children, without severe illness and abnormal delivery history, aged one to 23 months were randomly selected from five districts of Shanghai. Under strict quality control system, their parents were interviewed with questionnaire to look into their familial and social environment, as well as sleep-related factors.

RESULTSFully-completed information was obtained in 1 129 of 1 252 children, with a response rate of 90.18%. Prevalence of sleep problems in children was 65.90% in Shanghai, remarkably higher than in the other areas. Prevalence of nightmare, level of fright at night, snore and sleep apnea in boys were significantly higher than those in girls. Prevalence of improper sleep habit in children was also higher, including sleeping with their parents, parental presence at sleep onset and irregular sleep time. Main risk factors related to children's sleep problems were maternal anxiety, children's irregular sleep time, parental presence at sleep onset, difficulty-type temperament and maternal poor sleep during pregnancy.

CONCLUSIONSIn Shanghai, prevalence of sleep problems in children aged one to 23 months was relatively higher and main risk factors for them were social, cultural and familial environment, especially negligence of cultivating proper sleep habit and parental improper response to children's poor sleep behavior.