Effect of Gestational Age on Fetal and Intervillous Blood Gas and Acid-Base Values in Human Pregnancy

Abstract

Intervillous, umbilical venous and umbilical arterial blood samples were obtained by cordocentesis or fetoscopically from 200 pregnancies at 16–38 weeks gestation. The fetuses were either not affected by the condition under investigation or it was one which would not affect blood gas and acid-base status. Blood pH, pO₂ pCO₂, bicarbonate, base excess and plasma lactate concentration were determined and ranges for each parameter are presented. Samples obtained fetoscopically were more acidotic, hypercapnic and had a greater base deficit than those obtained by cordocentesis. In the umbilical venous samples, the pCO₂ decreased, while the bicarbonate, base excess and lactate increased with gestation. In the umbilical arterial samples the pO₂ decreased and pCO₂ increased; there were no other significant changes with gestation. Similarly, in the intervillous samples the only significant change with gestation was that of a ecrease in pO₂·

Carbon Monoxide Inhibits Hypoxia/Reoxygenation-Induced Apoptosis and Secondary Necrosis in Syncytiotrophoblast

“…A normoxic environment was established using a 5% O 2 /90% N 2 /5% CO 2 gas mixture resulting in pO 2 of 45 to 62 mmHg 6 in the culture medium, a concentration that is similar to the oxygen tension measured within the intervillous space of term placenta. 41,42 All explants were incubated at 37°C throughout the experiment. At time 0, 3, 6, and 12 hours (in the subset of repeated H/R insult experiments) explants were collected from all experimental groups and either flash-frozen for molecular analysis or fixed in paraformaldehyde for histological analysis.…”

Three cases of fetal ascites with successful outcome and seven year evaluation of NIHF: 1981-1987.

“…Umbilical vessel puncture under ultrasound guidance has recently been performed in some institutes for this reason. According to the results this maneuver is both safe and valuable for fetal diagnosis and as a therapeutic procedures (Soothhill et al 1986 ;Hsich et al 1987). We performed umbilical puncture in these three cases and successfully diagnosed normal karyotype in two cases.…”

Molecular Control of Cardiac Fetal/Neonatal Remodeling

“…Oxygen tension in adult mammalian arteries at sea level is approximately 100 mmHg, whereas in the fetal placental vein it is in the range of 20-30 mmHg in humans and other mammals [14][15][16]. HIF signaling is likely to be of prime importance in this context, given its well-established role in controlling metabolism in the adult heart [17].…”