The Association between Prenatal Cigarette Exposure and Behavioral and Physiological Reactivity during Infancy

The purpose of this study was to examine the association of prenatal exposure to cigarettes to measures of reactivity at 2 and 9 months of age. 191 9-month old infants (134 exposed, 57 nonexposed) were recruited prenatally. Cigarette exposure status was determined by a combination of maternal report, chart review, maternal salivary cotinine, and infant meconium. At 2-months, temperamental reactivity was assessed with the distress to limitations subscale of the revised Infant Behavior Questionnaire (IBQ-R; Garstein & Rothbart, 2003). Behavioral reactivity consisted of infant negative affect assessed during a mother-infant feeding interaction. Physiological reactivity was assessed with respiratory sinus arrhythmia (RSA) at the 9-month laboratory assessment during a negative affect (NA) paradigm. The NA paradigm consisted of a gentle arm restraint episode. Average RSA was calculated for baseline, and for the NA paradigm. To assess physiological reactivity, a change score for RSA from baseline to NA was calculated. Negative scores indicate a decrease in RSA and more optimal regulation during challenge. Structural Equations Modeling used to test the model indicated a significant direct association between prenatal cigarette exposure and physiological reactivity during frustration. Exposed children had a smaller decrease in RSA during the NA task indicating less optimal reactivity in response to frustration. Temperamental and behavioral reactivity at 2 months of age were also both associated with physiological reactivity at 9 months of age. Higher levels of negative affect and higher scores on the distress to limitations subscale were associated with smaller decreases in RSA.