Fetal heart rate abnormalities after regional analgesia for labor pain: the effect of intrathecal opioids.

Abstract

Intrathecal opioids used to relieve labor pain have been associated with uterine hyperactivity and nonreassuring fetal heart rate abnormalities. We retrospectively evaluated all charts of singleton, term, vertex-presenting parturients in active labor requesting neuraxial pain relief during a 1-year period for the occurrence of nonreassuring fetal heart rate tracings. Three different strategies to relieve labor pain were routinely used in our department: conventional epidural using 10 mL bupivacaine 0.125% and sufentanil 0.75 microg/mL; combined spinal and epidural (CSE) using intrathecal sufentanil (7.5 microg); and CSE using intrathecal bupivacaine (2.5 mg) and sufentanil (1.5 microg). Charts (n = 1,293) were evaluated for nonreassuring fetal heart tracings and uterine hyperactivity as well as for neonatal and labor outcome. Intrathecal sufentanil (7.5 microg) produced significantly more nonreassuring tracings and uterine hyperactivity. However, this did not result in more cesarean deliveries or detrimental neonatal outcome. Based on this retrospective analysis, we conclude that intrathecal sufentanil in a dose of 7.5 microg has the potential to result in more nonreassuring fetal heart rate tracings compared with both intrathecal analgesia using a bupivacaine (2.5 mg)/sufentanil (1.5 microg) mixture and epidural analgesia using bupivacaine, sufentanil, and epinephrine. Reg Anesth Pain Med 2001;26:257-262.