Self-regulation and emotional reactivity in infants with prenatal exposure to opioids and alcohol

Background: Infants with prenatal substance exposure are at increased risk for developmental problems, with self-regulatory challenges being some of the most pronounced. The current study aimed to investigate the extent to which prenatal substance exposure (alcohol, opioids) impacts infant self-regulation during a relational stressor and the association between self-regulation and infant affect. Methods: Participants were 100 mother-child dyads recruited prenatally (Mean = 23.8 gestational weeks) and completed the Still Face Paradigm (SFP) when infants were 5 to 8 months of age (Mean = 6.9 months) as part of an ENRICH prospective birth cohort study. Based on prospective repeated assessment of maternal substance use in pregnancy, infants were grouped into: 1) Unexposed controls; 2) Alcohol-exposed; 3) Opioid-exposed due to maternal use of medications for opioid use disorder (MOUD) with or without other opioids; 4) MOUD and alcohol. Infant stress reactivity (negative affect) and self-regulation were assessed during the validated 5-episode SFP. Mixed effects linear models were used to analyze differences in the percent of self-regulation and percent of negative affect among the study groups across SFP episodes, as well as the group-by-self-regulation interaction with respect to infant negative affect. Results: The MOUD +Alcohol group demonstrated significantly lower self-regulation at baseline compared to controls (p < 0.05). There was a significant group-by-self-regulation interaction (p = 0.028). Higher self-regulation was associated with lower negative affect across SFP episodes in the MOUD + Alcohol group (p = 0.025) but not other groups. Conclusion: Self-regulation skills are particularly important for emotional modulation in infants with prenatal polysubstance exposure, highlighting the development of these skills as a promising intervention target.