The effect of prenatal substance use and maternal contingent responsiveness on infant affect.

BACKGROUND

The effects of prenatal substance exposure on neurobehavioral outcomes are inherently confounded by the effects of the postnatal environment, making it difficult to disentangle their influence. The goal of this study was to examine the contributing effects of prenatal substance use and parenting style (operationalized as contingent responding during the play episodes of the Still-face paradigm [SFP]) on infant affect.

METHODS

A prospective cohort design was utilized with repeated assessment of substance use during pregnancy and the administration of the SFP, which measures infant response to a social stressor, at approximately 6months of age. Subjects included 91 dyads classified into four groups: 1) Control (n=34); 2) Medication assisted therapy for opioid dependence (MAT; n=19); 3) Alcohol (n=15); 4) Alcohol+MAT (n=23). Mean % of positive infant affect and mean % of maternal responsiveness (watching, attention seeking, and contingent responding) was compared among the five SFP episodes across the four study groups by MANOVA. Mixed effects modelling was used to estimate the contributing effects of the study groups and maternal responsiveness on infant affect.

RESULTS

Maternal contingent responding was associated with increase (β̂=0.84; p<0.0001) and attention seeking with decrease (β̂=-0.78; p<0.0001) in infant positive affect. The combined effect of prenatal exposures and covariates explained 15.8% of the variability in infant positive affect, while the model including contingent responding and covariates explained 67.1% of the variability.

CONCLUSIONS

Higher maternal responsiveness was a much stronger predictor of infant behavior than prenatal exposures, providing the basis for future intervention studies focusing on specific parenting strategies.