TY - CHAP
T1 - Blood Flow and Respiratory Gas Exchange in the Human Placenta at Term
T2 - A Data Update
AU - Vaupel, Peter
AU - Multhoff, Gabriele
N1 - Publisher Copyright:
© 2022, Springer Nature Switzerland AG.
PY - 2022
Y1 - 2022
N2 - Reliable measurements using modern techniques and consensus in experimental design have enabled the assessment of novel data sets for normal maternal and foetal respiratory physiology at term. These data sets include (a) principal factors affecting placental gas transfer, e.g., maternal blood flow through the intervillous space (IVS) (500 mL/min) and foeto-placental blood flow (480 mL/min), and (b) O2, CO2 and pH levels in the materno-placental and foeto-placental circulation. According to these data, the foetus is adapted to hypoxaemic hypoxia. Despite flat oxygen partial pressure (pO2) gradients between the blood of the IVS and the umbilical arteries of the foetus, adequate O2 delivery to the foetus is maintained by the higher O2 affinity of the foetal blood, high foetal haemoglobin (HbF) concentrations, the Bohr effect, the double-Bohr effect, and high foeto-placental (=umbilical) blood flow. Again, despite flat gradients, adequate CO2 removal from the foetus is maintained by a high diffusion capacity, high foeto-placental blood flow, the Haldane effect, and the double-Haldane effect. Placental respiratory gas exchange is perfusion-limited, rather than diffusion-limited, i.e., O2 uptake depends on O2 delivery.
AB - Reliable measurements using modern techniques and consensus in experimental design have enabled the assessment of novel data sets for normal maternal and foetal respiratory physiology at term. These data sets include (a) principal factors affecting placental gas transfer, e.g., maternal blood flow through the intervillous space (IVS) (500 mL/min) and foeto-placental blood flow (480 mL/min), and (b) O2, CO2 and pH levels in the materno-placental and foeto-placental circulation. According to these data, the foetus is adapted to hypoxaemic hypoxia. Despite flat oxygen partial pressure (pO2) gradients between the blood of the IVS and the umbilical arteries of the foetus, adequate O2 delivery to the foetus is maintained by the higher O2 affinity of the foetal blood, high foetal haemoglobin (HbF) concentrations, the Bohr effect, the double-Bohr effect, and high foeto-placental (=umbilical) blood flow. Again, despite flat gradients, adequate CO2 removal from the foetus is maintained by a high diffusion capacity, high foeto-placental blood flow, the Haldane effect, and the double-Haldane effect. Placental respiratory gas exchange is perfusion-limited, rather than diffusion-limited, i.e., O2 uptake depends on O2 delivery.
KW - Foetal haemoglobin
KW - Foeto-placental blood flow
KW - Haemoglobin oxygen affinity
KW - Placental gas transfer
UR - http://www.scopus.com/inward/record.url?scp=85144588030&partnerID=8YFLogxK
U2 - 10.1007/978-3-031-14190-4_62
DO - 10.1007/978-3-031-14190-4_62
M3 - Chapter
C2 - 36527666
AN - SCOPUS:85144588030
T3 - Advances in Experimental Medicine and Biology
SP - 379
EP - 384
BT - Advances in Experimental Medicine and Biology
PB - Springer
ER -