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Change in heart rate variability in relation to a significant ST‐event associates with newborn metabolic acidosis
Author(s) -
Siira S,
Ojala T,
Ekholm E,
Vahlberg T,
Blad S,
Rosén KG
Publication year - 2007
Publication title -
bjog: an international journal of obstetrics and gynaecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.157
H-Index - 164
eISSN - 1471-0528
pISSN - 1470-0328
DOI - 10.1111/j.1471-0528.2007.01369.x
Subject(s) - metabolic acidosis , medicine , cardiology , acidosis , cardiotocography , fetus , fetal heart rate , pregnancy , heart rate , blood pressure , biology , genetics
Objective To find whether low‐to‐high frequency (LF/HF) ratio of fetal heart rate (FHR) variability changes in relation to a significant ST‐event during delivery, and if the change is predictive of metabolic acidosis of the newborn. Design A case–control study. Setting Data from a multicentre project. Subjects Acidotic and control fetuses with abnormal cardiotocography together with a ST‐event in fetal electrocardiogram (ECG). Methods We studied intrapartum FHR variability with spectral analysis from 34 fetuses with a significant ST‐event in the fetal ECG. LF/HF ratio of FHR variability was measured within a period of 1 hour before and 1 hour after a significant ST‐event. Sensitivity and specificity of the change in LF/HF ratio of FHR variability in prediction of metabolic acidosis (pH ≤ 7.05 and base deficit value > 12.0 mmol/l) of the newborn were described by means of the receiver operating characteristic curve. Main outcome measures Change in LF/HF ratio of FHR in relation to a significant ST‐event. Results We found that a relative change in LF/HF ratio greater than 30% in relation to a significant ST‐event predicted cord arterial metabolic acidosis with a sensitivity of 89% (95% CI 68–100%) and specificity of 80% (95% CI 64–96%). Conclusions Relative changes in LF/HF ratio of FHR variability in relation to a significant ST‐event are more pronounced in fetuses born with metabolic acidosis.