(784) Neonatal Outcomes Among Individuals with Depressed Fetal Heart Tracings at Methadone and Buprenorphine Peak Levels

Medications for opioid use disorder (MOUD) have been shown to have depressive effects on the fetal heart tracing (FHT) in the antenatal setting however the impact of these findings at the time of labor and delivery is not well characterized.  We evaluated a cohort of birthing persons administered MOUD during the delivery hospitalization and compared neonatal outcomes in those with and without fetal heart tracing alterations at peak dose.

Study Design:

We studied a retrospective cohort of term singleton pregnancies with MOUD administration during labor and delivery at an academic urban hospital from 2016-2023. MOUD dose, dosing time, psychotropic medications, non-prescribed substance exposures, pregnancy complications, and mode of delivery were obtained via chart review. Clinically documented FHT variability and accelerations were collected at pharmacological trough and peak levels. FHTs with greater than 45 minutes of minimal variability during the peak period were characterized as minimal, and those without accelerations for more than 1 hour were characterized as absent. Tracings with minimal variability and absent accelerations were compared to reassuring tracings for differences in neonatal outcomes.

Results:

Of the 77 dyads who met inclusion criteria, 15 (19%) had fetal heart tracings with minimal variability and 43 (56%) had absent accelerations. Individuals who received methadone at delivery were more likely to exhibit minimal variability at peak dose (p= .03). Individuals cotreated with SSRIs/SNRIs were more likely to exhibit absent accelerations at peak dose (p=.001). However, there were no statistically significant difference in APGARS, NICU admission, respiratory distress or cesarean section rates in the cohort with reassuring fetal heart tracings versus those with predominantly minimal variability or absent accelerations.

Conclusion:

Fetal heart rate tracing depression should be interpreted with caution among birthing individuals receiving methadone or buprenorphine treatment at the time of labor and delivery.