From the Research
Management of fetal bradycardia during labor requires prompt intervention to improve fetal oxygenation and prevent adverse outcomes, with the most recent and highest quality study suggesting that any acute fetal hypoxia should be considered an intrapartum emergency requiring immediate intervention 1. The initial steps in managing fetal bradycardia include discontinuing any oxytocin if being administered and positioning the mother on her left side to relieve potential cord compression and improve uteroplacental blood flow.
- Administer oxygen via face mask at 8-10 L/min to increase maternal oxygenation and fetal oxygen delivery.
- Increase intravenous fluids (typically normal saline or lactated Ringer's) to improve maternal blood pressure and placental perfusion.
- Perform a vaginal examination to check for cord prolapse, rapid cervical dilation, or fetal head compression. If hypotension is present, administer vasopressors such as ephedrine 5-10 mg IV or phenylephrine 50-100 mcg IV.
- For uterine tachysystole, consider tocolytics like terbutaline 0.25 mg subcutaneously or nitroglycerin 50-100 mcg IV. If bradycardia persists beyond 3-5 minutes despite these measures, prepare for emergency delivery, which may require cesarean section, as the risk of hypoxic-ischemic injury to the deep gray matter of the brain increases with prolonged deceleration 1. These interventions aim to address the underlying causes of bradycardia, which typically include cord compression, placental insufficiency, maternal hypotension, or excessive uterine activity, all of which can compromise fetal oxygenation and lead to acidosis if not promptly corrected. Regular clinical audit of the management of acute hypoxia, including the "onset of bradycardia to delivery interval," may help identify organizational and system issues, which may contribute to poor perinatal outcomes 1. Decision analysis algorithms for fetal bradycardia highlight diagnostic limitations and the need for informed, shared, family-centered decision-making 2. In cases of uterine hypertonus or hyperstimulation, acute tocolysis is recommended to rapidly restore fetal oxygenation 1. The administration of oxytocin should be carefully managed, as it can cause patient harm if used in error, highlighting the importance of precise administration using infusion pumps, institutional safety checklists, and trained nursing staff to closely monitor uterine activity and fetal heart rate changes 3. In the presence of a structurally normal heart, complete atrioventricular block (CAVB) is the most common cause of persistent fetal bradycardia, and transplacental treatment strategies are aimed at preventing or modulating these risk factors 4.