Endovaginal pulsed and color Doppler techniques were used to evaluate
23 unselected first-trimester pregnancies prior to elective abortion.
Mean estimated gestational age was 8.9 +/- 1.6 weeks (range = 6.6-13.0
). Low impedance, high velocity peritrophoblastic flow was seen in all
cases. Mean peak systolic and end-diastolic velocities were 41.0 +/-
19.7 and 22.9 +/- 6.5 cm/s; mean resistance index (RI) was 0.41 +/- 0.
10. Forty-five uterine arteries were evaluated with mean peak systolic
and end-diastolic velocities of 44.1 +/- 14.7 and 7.6 +/- 4.3 cm/s; m
ean RI was 0.81 +/- 0.10. The peritrophoblastic and uterine artery vel
ocities did not correlate with gestational age. Both ovaries were eval
uated in 14 patients. One had no detectable flow in either ovary. For
the active ovary in the other 13 patients, mean peak systolic and end-
diastolic velocities were 27.4 +/- 9.9 and 15.2 +/- 5.9 cm/s; mean RI
was 0.44 +/- 0.09. The corresponding values for the inactive ovary wer
e 8.9 +/- 3.8 cm/s, 2.0 +/- 2.0 cm/s, and 0.76 +/- 0.22. These results
can be used as a baseline for future studies of abnormal pregnancies.