Prospective observational study quantifying maternal-fetal fentanyl transmission in epidural analgesia infusion using umbilical cord blood and neonatal meconium

Objective: To determine whether fetal exposure to maternal epidural fentanyl can result in a positive meconium drug test. Study design: Quantitative evaluation of fentanyl levels in cord blood and meconium of infants ≥37 weeks whose mothers received epidural analgesia was performed using High Performance Liquid Chromatography-tandem Mass Spectrometry. The association between dose and duration of maternal epidural and fentanyl levels in cord blood and meconium was evaluated. Results: In 298 mother-infant dyads, median duration of fentanyl epidural was 6.8 hours. There was a strong positive correlation between epidural duration and fentanyl levels in meconium (Spearman rho = 0.70, 95%CI [0.64-0.76]), p < 0.001). Positive predictive value for fentanyl detection in meconium >0.05 ng/g for epidural exposure of >4 hours was 93.9%. Conclusion: There is a strong positive correlation between maternal epidural duration and fentanyl in meconium. Providers can anticipate a positive meconium drug screen for fentanyl in the setting of a maternal epidural.