Template:Placenta Villi Timeline table

Placenta Villi Timeline

Fertilization Age (weeks)	Gestational Age (weeks)	Vessel Lumen Diameter (range in microns)	Features
3 to 4	5 and 6	10 - 15	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 (centrally and peripherally) contact 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 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
Term			Terminal villi have an extensive surface area >10 m2 small calibre (40 – 100 µm)
Table data Paper uses clinical gestational age (GA) table corrected also for post-conception (fertilization) age.