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In Vitro Culture of Epithelial Cells from Different Anatomical Regions of the Human Amniotic Membrane
Published on: November 28, 2019
On the origin of amniotic fluid bilirubin
E Sikkel1, S A Pasman, D Oepkes
1Department of Obstetrics and Gynecology, K6-32, Leiden University Medical Center, P.O. Box 9600, 2300 RC Leiden, The Netherlands.
Abstract:
We studied the relationship between bilirubin concentrations in amniotic fluid and fetal blood in 68 non-hydropic rhesus d-alloimmunized anemic fetuses at first blood sampling. In these alloimmunized fetuses, the amniotic fluid/fetal blood ratio for bilirubin decreased from 0.09 at 28 weeks to 0.05 at 33 weeks. In normal fetuses, amniotic fluid/fetal blood ratios for bilirubin, and for albumin, are in the same range and show a similar decrease during gestation. We conclude that amniotic fluid bilirubin concentration is determined, firstly, by fetal blood bilirubin concentration and, secondly, by the amniotic fluid/fetal blood ratio of albumin. Among five possible pathways bilirubin could take to build up a concentration in amniotic fluid (fetal kidneys, lungs, skin, bowel, membranes), the intramembranous pathway is the only one that is compatible with the amniotic fluid/fetal blood ratios for bilirubin that we found and must therefore be the most important.
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