Mothers who stopped smoking during pregnancy were more likely to have infants with easy dispositions than were mothers who continued to smoke.
Although maternal smoking during pregnancy is associated with increased risk for behavior problems in offspring, little is known about the early emergence of these problems. To determine the relation between maternal smoking patterns during pregnancy and infant temperament, researchers analyzed data from the Millennium Cohort Study, a prospective study of more than 18,000 infants born from 2000 to 2002 in the U.K. The Carey Infant Temperament Scale was used to assess positive mood, receptivity to novelty, and regularity (the extent to which the infant’s physiological functions are rhythmic or irregular) at age 9 months. Mothers were classified retrospectively into four categories by self-reported smoking status during pregnancy: never smoke…