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Published on: August 2, 2017
[Indirect standard cardiotocography plus fetal blood sampling versus indirect quantitative cardiotocography--a
Introduction:
In previous papers we proposed ways to improve the diagnostic potential of the "quantitative cardiotocography" computer method, which allowed us to introduce clinical practice guidelines. Using these guidelines we aim to evaluate the effectiveness of quantitative cardiotocography (qCTG) as compared to standard cardiotocography (CTG) and, if necessary fetal blood sampling (FBS).
Material And Methods:
The prospective study involves 220 pregnant women divided randomly into two groups. All 110 women in the control group were monitored by standard indirect cardiotocography Interpretation of CTG findings was performed according to the latest revision of FIGO classification. We performed FBS in all cases of abnormal or suspect CTG tracings and pH values below 7.20 were indicative for urgent delivery. If pH values were in the range between 7.20 and 7.25, another FBS was carried out after 30 minutes. If pH was above 7.25, FBS was repeated according to CTG evaluation by the attending doctor. All patients in the index group (110 women) were monitored by indirect quantitative cardiotocography (qCTG). Our clinical practice guidelines were used for the interpretation of CTG tracings. Obstetric behavior was strictly based on the recommendations in these guidelines. Outcome measures are: incidence of metabolic acidosis (defined by pH < 7.05 and BE > -12 mmol/l in the umbilical cord artery of the newborn), number of instrumental deliveries and sensitivity/specificity of each method (qCTG and CTG + FBS) in relation to fetal hypoxia (defined by pH < 7.20).
Results:
In the CTG group, 4.4% of the newborns were affected by metabolic acidosisas opposed to 2.2% in the qCTG group (P > 0.05). The sensitivity/specificity rates for fetal hypoxia were 89/67% (control group) and 97/85% (index group). The number of operative deliveries was 27.25% and 16.35%, respectively (P < 0.05).
Conclusion:
The incidence of metabolic acidosis was comparable in both groups. Indirect quantitative cardiotocography shows much better specificity for fetal hypoxia which results in significantly lower rates of operative deliveries compared to standard indirect cardiotocography combined with fetal blood sampling.
