///2016 Abstract Details
2016 Abstract Details2019-07-15T10:10:51-05:00

Fetal Response to Labor Epidural Initiation– Finding the Best Solution

Abstract Number: SA-29
Abstract Type: Original Research

Diana T Phan M.D. 1 ; Dmitry Portnoy M.D.2; Joseph Rinehart M.D.3

Introduction: There is a long-standing concern that Combined Spinal Epidural (CSE) for neuraxial labor analgesia initiation (NLAI) is associated with increased risk of fetal heart rate abnormalities (FHRA), mostly bradycardia. The risk is traditionally linked to relatively large doses of spinal opioids. We propose using a low dose fentanyl (from pharmacy pre-made epidural solution), which provides excellent NLAI while minimizing FHRA. We did a large-scale retrospective study to assess the risk of FHRA following low dose fentanyl CSE compared to bupivacaine only CSE and straight epidural (SE) initiation.

Method: We reviewed electronic medical records of all parturients who received NLAI at our institution in 2014. We collected demographic and obstetric data, pain scores, blood pressures (BP), FHRA events, body mass index (BMI) and Apgar scores. Patients were divided into groups based on the type of NLAI: low dose fentanyl/bupivacaine CSE (2.5 mg bupivacaine with fentanyl 5 mcg, CSE+), bupivacaine alone CSE (2.5 mg, CSEo), and SE. A generalized linear model was built using the presence or absence of FHRA as a logistic outcome and demographic and obstetric data as independent or random factors.

Result: 709 records were reviewed (345 CSE+, 138 CSEo, 226 SE). Type of NLAI was non-predictive of FHRA (p=0.71, Figure 1). In the logistic model, predictors of FHRA were increased parturient age (p=0.028) and decreased BP 15 min after NLAI (p=0.042). Factors predictive of low BP 15 min after NLAI were lower BMI (p=0.003) and lower gestational age (p=0.005). There were no significant differences in Apgar scores and post-NLAI pain scores reduction between the groups.

Conclusion: CSE initiation with 5 mcg of fentanyl and bupivacaine is not associated with increased risk of FHRA compared to CSE with bupivacaine alone or SE initiation. There is no difference in Apgar scores or maternal outcome between groups. This solution provides an effective, safe and cost-effective method for NLAI. In patients with increased age, low BMI, low pre-NLAI BP, or low gestational age, precautions should be taken to reduce the impact of NLAI on BP.


1. Patel NP et al. Fetal effects of combined spinal-epidural vs epidural labour analgesia: a prospective, randomized double-blind study. Anaesthesia 2014; 69: 458–67.

2. Palmer CM et al. The incidence of fetal heart rate changes after intrathecal fentanyl labor analgesia. Anesth Analg. 1999 Mar;88(3):577-81.

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