Effect of physiologic perfusion-fixation on the morphometrically evaluated dimensions of the term placental cotyledon.
OBJECTIVE
To estimate the in vivo dimensions of the fetal villous tree of the normal term placenta.


METHODS
Dual-circuit perfusion-fixation of a cotyledon from eight normal term placentas was performed with random intra-cotyledon tissue sampling. Stereologic methods were used to derive estimates of villous (intermediate and terminal) surface area and volume, and star volume (a measure of villous volume).


RESULTS
Villous surface area (mean 20.9 m2 [standard deviation 1.8]), capillary surface area (12.8 m2 [1.5]), villous volume (469 mL [40]), and capillary volume (80 mL [10]) values were all approximately 50% higher than reported previously. Star volume estimates ranged from 480 to 1350 microns 3.


CONCLUSIONS
Tissue perfusion-fixation more accurately reconstructs the in vivo state, resulting in higher reference values than previously thought for the fetal villous tree dimensions. Up to one-quarter of fetoplacental blood volume is likely to be accommodated within the placenta at term.
Luckhardt
M
M
Department of Obstetrics and Gynaecology, University of Berne, Switzerland.
Leiser
R
R
Kingdom
J
J
Malek
A
A
Sager
R
R
Kaisig
C
C
Schneider
H
H
D001724:Birth Weight; D002196:Capillaries / Q000166:cytology / Q000502:physiology; D002824:Chorionic Villi / Q000502:physiology; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D010920:Placenta / Q000098:blood supply / Q000166:cytology* / Q000502:physiology*; D011247:Pregnancy; D014470:Umbilical Cord / Q000502:physiology