[T/QRS-ratio and cardiotocographic changes in the second stage of labor--related to fetal condition at delivery].
The T/QRS ratio of the foetal electrocardiogram (ECG) was recorded from 92 women in labour. Recordings to within 30 min of delivery from 55 women were available for analysis. There was a weak but statistically significant correlation between increasing mean T/QRS ratio and increasing pH/standard base excess (SBE) in the umbilical artery of the 55 foetuses (Spearman, respectively r = 0.28, p = 0.04 and r = 0.29, p = 0.04); the corresponding numbers for the subgroup of 22 where the cardiotocogram was classified as normal being respectively r = 0.51, p = 0.02 and r = 0.61, p = 0.003. The mean T/QRS ratio of foetuses born with an umbilical artery pH of > 7.15 was 0.12 (range -0.05-0.32). There was no significant difference in mean T/QRS ratio between foetuses born with an umbilical artery pH < 7.16 (n = 10) and those born with a pH > 7.15. No trend in T/QRS ratio was found as labour progressed. There were only three cases of metabolic acidose (SBE = -10.3 to -10.6 mmol/l and pH = 7.09-7.14. In two of the cases the CTG was abnormal and in one case intermediate; mean T/QRS ratio was normal in all three cases with metabolic acidosis. Abnormal CTG was able to predict an umbilical artery pH < 7.15 with a sensitivity of 67% and a positive predictive value of 27%. T/QRS ratio (T/QRS = -0.05-0.25: "normal") was not able to predict a low pH. The chance of finding significant changes in T/QRS ratio was limited by the small number of foetuses with clinically significant acidosis.(ABSTRACT TRUNCATED AT 250 WORDS)
Jensen
L M
LM
Gynaekologisk-obstetrisk afdeling, Hvidovre Hospital, København.
Nickelsen
C N
CN
Weber
T
T
D000293:Adolescent; D000328:Adult; D001034:Apgar Score; D015148:Cardiotocography; D004562:Electrocardiography; D005260:Female; D005323:Fetal Monitoring / Q000379:methods*; D006340:Heart Rate, Fetal / Q000502:physiology*; D006801:Humans; D007231:Infant, Newborn; D007748:Labor Stage, Second / Q000502:physiology*; D011247:Pregnancy; D011446:Prospective Studies
T/QRS-ratio og kardiotokografiforandringer i andet stadium af fødslen--relateret til fostrets tilstand ved fødslen.