Measurement of transcutaneous pCO2 and pO2 in the fetus during labor

Abstract

We used newly developed transcutaneous electrodes to measure continuously the partial pressure of oxygen (tcpO2) and carbon dioxide (tcpCO2) in 34 fetuses during labor, having simultaneous cardiotocography (CTG) and temperature measurements. We observed that tcpO2 and tcpCO2 varied with contractions during the first and second stages of labor. In some cases changes in the transcutaneous values corresponded well with changes in the CTG, we also detected changes in the fetal gas metabolism that were not noticeable on the cardiotocographic tracing. We defined the characteristic of the tcpO2 and tcpCO2 during the second stage of labor and found that the tcpO2 decreased and the tcpCO2 rose at this time.

Clinical evaluation of Statstrip® Lactate for use in fetal scalp blood sampling

“…A normal pH with a high lactate can be explained by: slow clearance of lactate from the fetal circulation and fast normalization of pH some time after an hypoxic insult; an early stage of a slowly developing acidosis; factors other than hypoxia, such as contamination of amniotic fluid or limited local perfusion as occurs with caput formation . Furthermore, the fetal acid–base balance is influenced by the administration of beta‐mimetic drugs, glucose, maternal hyperventilation and catecholamine concentrations . It might therefore be wise to perform parallel analyses of both pH and lactate in FBS, as they might mirror different stages of a developing asphyxia.…”

“…(3) factors other than hypoxia, such as contamination of amniotic fluid or limited local perfusion as occurs with caput formation (8,12,15,16). Furthermore, the fetal acidbase balance is influenced by the administration of betamimetic drugs, glucose, maternal hyperventilation and catecholamine concentrations (17,18). It might therefore be wise to perform parallel analyses of both pH and lactate in FBS, as they might mirror different stages of a developing asphyxia.…”

Fetal Release of Copeptin in Response to Maternal Oxytocin Administration

“…Mild uterine contractions lead to brief pO 2 drops in the fetus, often without noticeable changes in fetal heart rate tracing. [13][14][15] Animal data indicate a direct and dose-dependent link between uterine contractions and fetal arterial pO 2 changes 16,17 and a relationship between arterial pO 2 and plasma AVP in fetal sheep. 18,19 Even changes in fetal arterial pO 2 as small as 2.5 mm Hg were sufficient to release corticotropin, an effector hormone of AVP and corticotropinreleasing hormone.…”

Der Einfluss einer modifizierten Gebärhaltung auf die Oxygenierung des Feten - Eine pulsoxymetrische Untersuchung1

“…Diese Veränderung wurde durch eine Kompression der Aorta in Rückenlage erklärt [3]. Das perinatalphysiologische Wissen wurde nunmehr mittels der im Laufe der Jahre vorhandenen Sensoren für die transkutane Blutgasmessung von Sauerstoffpartialdruck (tcpO 2 ) und Kohlendioxidpartialdruck (tcpCO 2 ) sowie neuerlich mit der Sensortechnik der fetalen Pulsoxymetrie (SpO 2 ) erweitert [5,10,18,19,20,21]. Es wurden Untersuchungen angestellt, um die aufgrund der physiologischen Vorteile der vertikalen Position erwarteten günstigeren Voraussetzungen für einen Sauerstofftransfer zum Feten zu verifizieren.…”