We present a case of a probably unnecessary Caesarean section due to misint
erpretation of the cardiotocography (CTG) trace during general anaesthesia.
A 27-yr-old patient in her 30th week of an uneventful, normal first pregna
ncy presented with a deep venous thrombosis in the pelvic region. She was t
o undergo an emergency thrombectomy under general anaesthesia. During the o
peration, the CTG showed a lack of beat-to-beat heart rate variation (silen
t pattern CTG) with normal fetal heart rate. This silent CTG pattern was pr
obably a result of the effect of general anaesthesia on the fetus. The CTG
pattern was interpreted as indicating fetal distress, and an emergency Caes
arean section was performed after the thrombectomy. The infant was apnoeic
and had to be resuscitated and admitted to the neonatal intensive care unit
. The pH at delivery was 7.23 and the baby was extubated 2 days later. Moth
er and child recovered without short-term sequelae. In the absence of alter
native explanations, reduced fetal beat-to-beat variability with a normal b
aseline heart rate during general anaesthesia is probably normal.