PHILADELPHIA (September 4, 2007) - - A study from the Monell Chemical Senses Center reports that nicotine in the breast milk of lactating mothers who smoke cigarettes disrupts their infants’ sleep patterns.“Infants spent less time sleeping overall and woke up from naps sooner when their mothers smoked prior to breastfeeding,” says lead author Julie A. Mennella, PhD, a psychobiologist at Monell.