Effect of Oxygen Inhalation by the Mother on Valuesof Oxygen Saturation of the Mother (SpO2)and the Foetus (FSpO2)

Overview

Objective:
The aim of the study was to evaluate the impact of different concentrations of inspira-ted O2 on the SpO2 values of the foetus and the mother during the 1 st and 2 nd stages of labor.Design: Prospective study.Setting: 1 st Department of Gynecology and Obstetrics, Medical Faculty of Masaryk University,BrnoMethods: 17 non-risk patients were enrolled in the study. The SpO2 levels of the mother and thefoetus were monitored simultaneously in 10 min intervals with the room air inspiration entrain-ment O2 mask and the inflatable face mask during 1 st and 2 nd stages of labor.Results: No changes in maternal SpO2 values were revealed in the three different O2 inspirationregimens neither in the 1 st , nor in the 2 nd stages of labor. The mean value was 98 % ± 1.6 SD. As forthe foetus the SpO2 values were increased by 6 % (± 7.9 SD) after 40 % concentration of O2 and7.7 % (± 8.8 SD) after 98 % O2 inspiration during the 1 st stage of labour. These values have decrea-sed promptly after the cessation of the O2 inspiration. The mean SpO2 values at room O2 concen-tration were 46.3 % ± 7.9 SD for the 1 st stage of labor and 43.7 % ± 4.8 SD for the 2 nd stage of labor.Conclusion: The O2 inspiration during the labor has no impact on the maternal SpO2 values butincreases the SpO2 values of the foetus during the 1 st stage of labor. We were not able to evaluatethe impact of the O2 inspiration on foetal SpO2 values during the 2 nd stage of labor.

Key words:
O2 inspiration, no risk pregnancy, intrapartum foetal pulse oximetry, oxygen satura-tion