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Published on: October 25, 2015
Predictive value of pulse oximetry for the development of fetal acidosis
Andreas Nonnenmacher1, Hartmut Hopp, Joachim Dudenhausen
1Department of Obstetrics, Charité - Universitätsmedizin Berlin, Berlin, Germany. Andreas.nonnenmacher@charite.de
Aims:
To determine the predictive value of fetal pulse oximetry (FPO) for the development of fetal acidosis in cases of non-reassuring fetal heart rate (FHR).
Methods:
In a prospective observational study, pulse oximetry monitoring was examined in cases of non-reassuring FHR during singleton cephalic delivery at 36-42 weeks' gestation. The study examined whether fetal arterial oxygen saturation (FSpO(2)) values <30% for at least 10 min during the last 60 min before delivery increase the risk of fetal acidosis. The predictive reliability of this algorithm and the correlation to fetal acidosis [umbilical artery pH (UApH) <7.15] were analyzed.
Results:
We included 101 patients with non-reassuring FHR during delivery. The incidence of fetal acidosis was significantly higher when FSpO(2) values <30% were recorded for at least 10 min (P=0.0). An UApH <7.15 was reliably excluded with a negative predictive value of 98.7% and detected with a sensitivity of 92.9%.
Conclusions:
A low pulse oximetry oxygen saturation <30% for at least 10 min correlates highly with fetal acidosis in cases of non-reassuring FHR. FPO reliably excludes moderate to advanced acidosis and can reduce the frequency of fetal blood analysis (FBA) in cases of non-reassuring cardiotocography (CTG).
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