Fellow Tufts Childrens Hospital Boston, Massachusetts, United States
Background: Opioid-exposed neonates are at risk of developing Neonatal Abstinence Syndrome (NAS), some needing pharmacotherapy for severe withdrawal. Autonomic nervous system (ANS) functioning, assessed with heart rate variability (HRV) and cortisol levels, may reveal early physiologic dysregulation associated with prenatal opioid exposure and has the potential to identify and allocate resources for high-risk neonates. Objective: Using HRV and cortisol levels from saliva and nail samples, we will examine the autonomic changes and stress response characteristics in opioid-exposed and non-exposed neonates. Design/Methods: This IRB-approved prospective observational study aims to enroll 20 opioid-exposed and 20 sex- and age-matched non-exposed neonates born at ≥ 34 weeks’ gestational age (GA). Neonates born amidst chorioamnionitis, acute perinatal events, and with congenital or chromosomal anomalies will be excluded. Clinical data to be collected include GA, delivery method, Apgar scores, sex, race, ethnicity, anthropometric data, need for pharmacotherapy, maternal opioid use, smoking, Hepatitis C infection, and GBS status. Within 48 hours of birth, saliva will be collected using validated methods, placed in protease inhibitor, and stored at -80°C until further processing. Using an electronic baby nail trimmer, nail samples will be concurrently collected and placed in methanol until further extraction. Cortisol levels will be analyzed using an enzyme-linked immunosorbent assay. HRV will be assessed during sleep using a bedside electrocardiogram on days 1 and 2 (for all neonates) and again on day 5 (for opioid-exposed neonates before discharge). The R-R intervals will be manually calculated and uploaded to validated analysis software (Kubios HRV). Data will be stratified by exposure and need for pharmacotherapy. Between-group comparison of variables will be analyzed with a t-test or Mann-Whitney U test for continuous data and a chi-squared test for categorical data. Data collection and analysis to be completed by March 2024.
