Fertilization Age
(weeks)
|
Gestational Age
(weeks)
|
Vessel Lumen Diameter
(range in microns, µm)
|
Features
|
3 to 4
|
5 and 6
|
10 - 15
|
- a complex network of cords and vessels with redundant connections
- network comprises mainly cords, already connected together
- vessels and cords are connected to each other without any interruptions
- chorionic villus dominated by this network of vascular elements
- vessels and cords are located centrally as well as peripherally and as a consequence contact the overlying trophoblastic layer
|
5 to 6
|
7 and 8
|
10 - 26
|
- villi dominated by capillary network of vessels and cords
- capillary network contains more vessels than cords
- chorionic villus tip - regular small branched off (mesenchymal) chorionic villi are present containing CD31 positive cells
|
7 to 8
|
9 and 10
|
60 - 75 two central vessels
26 - 34 capillary network
|
- villi have two large centrally located vessels
- surrounded by and connected to a peripheral capillary network
- capillary network contains vessels with a lumen in tight contact with overlying trophoblastic layer
- villous projections also contain blind ending capillary sprouts
|
9 to 10
|
11 and 12
|
70 - 90 two central vessels
26 - 34 capillary network
|
- immature intermediate villi characterized by two large vessels surrounded by a capillary network
- capillary network has few cords
- blind ending capillary sprouts off the capillary network
|
Vill development data based upon immunochemistry confocal laser scanning microscope (CLSM) study[1] with clinical gestational age (GA) from last menstrual period (LMP) and has been corrected for post-conception (fertilization) age, approximately 14 days later.
CD31 - (PECAM-1, Platelet Endothelial Cell Adhesion Molecule) is a cluster of differentiation molecule found on endothelial and other blood cells.
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