Sc. Mitra et al., MORPHOMETRIC STUDY OF THE PLACENTAL VESSELS AND ITS CORRELATION WITH UMBILICAL ARTERY DOPPLER FLOW, Obstetrics and gynecology, 89(2), 1997, pp. 238-241
Objective: To determine the changes in the vessel-wall thickness and t
he radius of the lumen in tertiary-stem villi of the placenta with adv
ancing gestational duration and their relationship to umbilical artery
Doppler flow studies. Methods: Placentas from 63 miscarriages and pre
term and term deliveries (between 19 and 40 weeks) were used for morph
ometric study of the tertiary-stem villi vessels. Each woman had under
gone Doppler now study of the umbilical artery. The resistance index (
RI) was determined from the Doppler flow velocity waveform. Placental
paraffin sections of 4-mu thickness were stained with hematoxylin and
eosin and with periodic acid-Schiff reagents. The tertiary-stem villi
and their vessels were examined microscopically and assessed morphomet
rically using a personal computer with math co-processor and a touch-s
ensitive screen overlying a video monitor. The monitor received micros
copic images from a video camera that was mounted on a microscope. We
determined vessel-wall thickness by tracing the outer and inner circum
ferences of digitized vessel-wall images.Results: Wall thickness, but
not lumen size, of the tertiary-stem villi vessels decreased significa
ntly overall at a rate of 0.63 mu/week (P < .001). The rate of decreas
e was 0.64 mu/week (P < .001) during the second trimester and 0.50 mu/
week (P < .001) during the third trimester. There was a significant co
rrelation between the decrease in thickness and in RI (r = 0.83 [P < .
001], r = 0.78 [P < .001] in the second and third trimesters, respecti
vely). Resistance indices were all within normal limits. Conclusion: P
lacental tertiary-stem villi vessel-wall thickness decreases with adva
ncing gestational age. There is a correlation between the changes in R
I of the umbilical artery Doppler flow and the changes in mean wall th
ickness of the placental vessels. Copyright (C) 1997 by The American C
ollege of Obstetricians and Gynecologists.