///2010 Abstract Details
2010 Abstract Details2019-08-03T15:49:10-06:00

Fetal bradycardia during labor analgesia: CSE versus standard epidural

Abstract Number: 44
Abstract Type: Original Research

Richelle N Medford MD1 ; Laurent A Bollag MD2; Kerry M McMahon MD3; Rebecca F Dunsmoor-Su MD, MSCE4; Michael G Gravett MD5; Ruth Landau MD6


CSE is increasingly used for labor analgesia due to the substantial benefits it provides. One persistent concern surrounding CSE analgesia is the risk of uterine hypertonus and fetal bradycardia (FB) associated with spinal opioids. We set out to compare FHR abnormalities, mode of delivery and neonatal outcomes associated with CSE versus EPID at our institution, as the OB anesthesia practice was to increase the rate of CSE.


We conducted a retrospective chart review of all women admitted to L&D from January to March 2009. Amongst those, all women requesting neuraxial analgesia were included. CSE or EPID was provided at the discretion of the attending anesthesiologist. In the CSE group, spinal solution was 2.5mg isobaric bupivacaine + fentanyl (10-25μg, most received 20μg). PCEA with bupivacaine 0.0625% + fentanyl 2μg/ml 10ml/h, bolus 5ml, lock-out 10min followed. In the EPID group, bupivacaine 0.25% 8-15ml was followed by fentanyl 50-100μg and a similar PCEA regimen. FHR tracings 1h before and 1h after analgesia were reviewed by 2 independent obstetricians blinded to analgesia technique. FB was defined by a 15 beat drop in baseline for >2min that was not present prior to analgesia.


401 women were admitted and delivered (89 without neuraxial analgesia, 72 with planned CS, 67 excluded due to prior FHR anomalies leaving n=173 eligible parturients): 91 with CSE vs 82 with EPID analgesia. FB occurred in 15% of CSE (n=14; all FB occurred with 20μg except for 1 FB after an unknown dose) and 4% of LEP (n=3) (RR 4.26; 95% CI 1.27-14.28;p<0.009).

No urgent CS was required in the hour following labor analgesia. CS rates and neonatal outcomes were similar in both groups. Parity did not influence the risk of developing FB.


Our findings confirm that spinal opioids increase risk of FB without impacting on mode of delivery or neonatal outcomes. Minimal medical interventions were required (ephedrine in 2 women, terbutaline in one). Dissemination of appropriate information and education regarding CSE use for labor analgesia should be implemented in institutions not otherwise familiar with this technique. While our sample is insufficient to draw any conclusions, our clinical impression is that lower doses (10μg) of fentanyl may reduce the likelihood of FB. Further prospective randomized trials should investigate the optimal dose of spinal fentanyl for labor analgesia to reduce the incidence of FB after CSE.

1.Obst Gynecol 2009;113:1374-5

SOAP 2010