Antepartum high-frequency fetal heart rate sinusoidal rhythm: computerized detection and fetal anemia.
OBJECTIVE
Our aim was to identify antepartum fetal heart rate (FHR) records of high-frequency (HF) sinusoidal rhythms from an electronic database (1983-2003) and determine clinical outcomes.


METHODS
At the John Radcliffe Hospital (Oxford, UK), 72,297 traces from 19,506 women were analyzed using an algorithm that identifies HF sinusoidal rhythms. The case records were reviewed.


RESULTS
There were 15 (0.21/1000) traces from 8 (0.41/1000) women with an HF sinusoidal rhythm. In 5 of 8 women (62.5%), this pattern was associated with fetal anemia (hemoglobin < 10.0 g/dL). Their FHR patterns were distinguished from those of the other nonanemic fetuses by significantly lower long-term variability.


CONCLUSIONS
An antepartum HF sinusoidal rhythm is rare but associated with fetal anemia, particularly if it is combined with reduced long-term variability without episodes of high FHR variability within 60 minutes. The automated system can alert inexperienced staff, who supervise FHR monitoring, by an online warning.
Reddy
Aparna
A
Nuffield Department of Obstetrics and Gynecology, University of Oxford, John Radcliffe Hospital, Oxford, UK.
Moulden
Mary
M
Redman
Christopher W G
CW
D000328:Adult; D000740:Anemia / Q000503:physiopathology*; D003936:Diagnosis, Computer-Assisted; D005260:Female; D005315:Fetal Diseases / Q000503:physiopathology*; D006340:Heart Rate, Fetal / Q000502:physiology*; D006801:Humans; D007231:Infant, Newborn; D011247:Pregnancy