Reproductive · Year 2 · from Reproductive
Case 2: Non-Reassuring Fetal Heart Rate Tracing
Clinical Image
Source: Wikipedia - Cardiotocography - CC BY-SA 3.0
Case Presentation
A 29-year-old G1P0 at 39 weeks gestation is admitted for labor induction due to gestational hypertension. Cervical ripening with misoprostol is performed, followed by oxytocin augmentation. After 8 hours, she is 5 cm dilated with ruptured membranes. Continuous fetal heart rate (FHR) monitoring shows a baseline of 145 bpm with moderate variability. Suddenly, repetitive late decelerations develop, with FHR dropping to 100 bpm starting 20-30 seconds after the peak of each contraction and not returning to baseline until well after the contraction ends. Variability becomes minimal. The provider recognizes this as a Category III FHR tracing indicating uteroplacental insufficiency. Intrauterine resuscitation is initiated: the patient is repositioned to left lateral decubitus, oxytocin is discontinued, IV fluid bolus is given, and oxygen is administered via face mask. Despite these measures, late decelerations persist with minimal variability. The decision is made for emergent cesarean delivery. A male infant is delivered with Apgar scores of 4 at 1 minute and 7 at 5 minutes, requiring positive pressure ventilation initially. Umbilical cord arterial pH is 7.15. The infant recovers well without evidence of hypoxic-ischemic encephalopathy.
Key Learning Points
- Late decelerations (onset after contraction peak, nadir after peak, gradual return to baseline) indicate uteroplacental insufficiency and fetal hypoxia
- Category III FHR tracings (absent variability with recurrent late or variable decelerations, bradycardia, or sinusoidal pattern) require immediate evaluation and intervention
- Intrauterine resuscitation includes position change, stopping oxytocin, IV fluids, oxygen, and amnioinfusion if indicated for variable decelerations
- If resuscitative measures fail, expeditious delivery is indicated to prevent fetal acidemia and hypoxic-ischemic injury