Thirty-eight consecutive patients with the diagnosis of abnormal early
singleton pregnancy were studied with transvaginal color velocity ima
ging and pulsed Doppler ultrasonography to assess corpus luteum blood
flow. Mean gestational age was 8.5 weeks (range, 6 to 12 weeks). Patie
nts' mean age was 30.9 years (range, 24 to 43 years). There were 19 (5
0%) threatened abortions, 13 (34.2%) missed abortions, and six (15.8%)
anembryonic pregnancies. Blood flow impedance in the corpus luteum wa
s estimated by calculating the resistive index. The results of this st
udy group were compared with those obtained in a series of 85 normal s
ingleton early pregnancies used as controls. Overall, detection of cor
pus luteum blood flow was 78.9% in study group and 76.4% in control gr
oup (P = 0.51). Mean resistive index +/- standard deviation in the con
trol group was 0.50 +/- 0.10; the corresponding values in threatened a
bortion, anembryonic pregnancy, and missed abortion were 0.52 +/- 0.10
, 0.42 +/- 0.06, and 0.57 +/- 0.05, respectively. No statistical diffe
rences in mean resistive index were found among threatened abortion an
d anembryonic pregnancy with respect to control group. A higher mean r
esistive index was observed in missed abortion than in control group (
P < 0.01). Ln conclusion, our data show that luteal vascularization mi
ght be decreased in missed abortion but not in threatened abortion and
anembryonic pregnancy.