Prenatal Substance As Related to Autonomic Regulation of Infants at 6 Months Old

• Zaw Htoo, Neuroscience, University of Delaware

• Mary Dozier, Psychology, University of Delaware

Substance use during pregnancy is known to have substantial impacts on infant development. Of particular concern is the impact of opioid use on autonomic nervous system regulation and whether there is a differential effect seen relative to the use of other substances. Autonomic nervous system regulation is measured via Respiratory Sinus Arrhythmia (RSA), the natural variation in heart rate when an individual inhales and exhales. Previous research has established lower baseline RSA and blunted or excessive reactivity to be associated with emotional dysregulation. This study analyzed a group of participants taken from a larger, longitudinal study. We examined the effects of opioid use during pregnancy on infants’ autonomic nervous system regulation at 6 months old, comparing these effects to mothers who had used substances other than opioids and to mothers who had not reported any substance use during pregnancy. Data on substance use were collected via the Timeline Followback interview. Autonomic nervous system regulation was assessed using electrocardiogram data. We measured Respiratory Sinus Arrhythmia at baseline as well as reactivity to a social stressor during the Still-Face Paradigm (SFP) and recovery following the end of the episode. Infants of mothers who had either used opioids, used other substances, or denied the use of substances did not differ significantly in RSA baseline, reactivity, or recovery. This is in contrast to previous research, which has established a significant effect of prenatal substance use on infants’ autonomic nervous system regulation at 6 months old.