Marijuana use while pregnant increases the chance of developing childhood sleeping problems as much as a decade later warn researchers. Published in Sleep Health: The Journal of The National Sleep Foundation the study is the latest to link prenatal cannabis use to developmental problems in children and the first to suggest it may impact sleep cycles long-term. According to researchers from the University of Colorado Boulder in the US mothers who said they smoked cannabis while pregnant were significantly more likely to report their children having clinical sleep problems. For the purpose of the study researchers analysed baseline data from