Monitoring of transcutaneous PO2 in the fetus and mother during normal labor.

Abstract

Transcutaneous PO2 (tcPO2) measurement is a non-invasive method which gives continuous information about central PO2. The method has previously been testes primarily on newborns and adults, and reports on the applicability of the method on the fetus during labor are still scanty and restricted to case reports. This paper reports on a systematic study of intrapartum fetal and maternal tcPO2-monitoring. The material is comprised of 19 parturients, the majority being nulliparae. All fetal presentations were vertex. The tcPO2 recordings averaged one hour in duration (Tab. I). FHR was recorded simultaneously. In 12 cases the electrode was affixed with glue, and in 7 cases a suction device was used for fixation. The electrode was attached when the cervix was dilated 4 to 6 cm. The mean tcPO2 was 20 mm Hg in the beginning of the registration, and showed a small decline in level throughout labor reaching 14 mmHg at the end of the registration period (Fig. 5). These values are in good agreement with those found by other authors in previous investigations. In some of the present cases, very low tcPO2 values were recorded. The relevance of these low tcPO2 values is unclear, and it is impossible to determine to what extent these tracings have true physiological relevance versus might be due to technical factors.