Chapter 27 - A technique for continuous measurements of materno-fetal gas transfer using mass spectrometry suitable for non-invasive intrapartum placental function testing in man

Abstract

Publisher Summary This chapter presents a technique for the continuous measurements of materno-fetal gas transfer using mass spectrometry suitable for noninvasive intrapartum placental function testing in man. The clinical assessment of fetal respiratory status in early labor depends largely on the interpretation of changes in the continuous fetal heart rate recording (FHR). Labor imposes a variety of endocrine, behavioral, and reflex stimuli on the fetal cardio-respiratory system that makes it unlikely that changes in the FHR pattern would have a direct relationship to acid–base status, except when the latter is significantly abnormal. In an attempt to improve the assessment of fetal reserve in early labor, the multi-gas sampling potential of the mass spectrometer have been used to make the continuous measurements of materno-fetal transfer of oxygen and helium. Animal experiments are currently being used to develop a short, repeatable test using argon, with the expectation of developing a simple test of placental transfer suitable for use in early human labor. Fetal respiration remains poorly understood and its monitoring during human labor is limited to noninvasive skin surface measurements. The first use of skin surface mass spectrometry was described by Delpy and Parker (1975) and the advantage of such a system is the ability to measure multiple gases using a single transducer.