A 36-year-old woman required excision of laryngeal granulomata in her 34th week of gestation. She had airway obstruction due to the granulomata and subglottic stenosis which resulted from emergent; intubation after a drug overdose 6 weeks earlier. Fetal heart rate pattern was normal. After IV administration of midazolam 2 mg, fentanyl 100 μg. thiamylal 250 mg, and slow infusion of succinylcholine, decreased beat-to-beat variability was noted within 3 min. Inhaled anesthetics included 50% N2O-O2-0.5% enflurane. Twenty minutes later, there was complete absence of beat-to-beat variability and a downward shift of the baseline from 150 beats/min to 130. Maternal BP decreased progressively from 152 94 to 110/60 mmHg. After the patient awakened, fetal heart rate pattern and baseline returned to normal A healthy infant was delivered vaginally 6 weeks later Since no uterine contractions occurred during the period of anesthetization, it may be assumed that these fetal heart rate changes resulted from interference with functioning of the fetal central nervous system by large doses of anesthetics traversing toe placenta. Thus, loss of beat-to-beat variability associated with general anesthesia is probably normal for the anesthetized fetus.