Case reports
We present 3 cases of documented central nervous system (CNS) injury with a characteristic fetal heart rate (FHR) sawtooth-like pattern. In the first case, there was category I fetal heart tracing during labor, which was followed by a sudden onset of fetal tachycardia, unstable and indeterminate baseline, and episodes of a sawtooth FHR pattern ( Figure 1 ).
The Apgar scores after a vaginal delivery were 9/9 at 1 and 5 minutes. The magnetic resonance imaging of the neonate, which was performed 48 hours postpartum because of facial twitches, showed infarction of the left cerebral hemisphere because of a middle cerebral artery occlusion/thrombosis; the approximate timing of the fetal stroke coincided with the abrupt onset of the aforementioned FHR changes in labor ( Figure 2 ).
In the second case, the patient was admitted with indeterminate FHR baseline and sawtooth FHR pattern ( Figure 3 ). Emergent cesarean delivery was performed and the Apgar scores were 0/3/3 at 1, 5, and 10 minutes; the umbilical artery cord pH was 6.87, partial pressure of CO 2 was 186, and base excess was –27.7. Immediately after birth the electroencephalogram was abnormal, and the infant received brain cooling but unfortunately died.
