Jl. Alcazar et al., TRANSVAGINAL COLOR DOPPLER ASSESSMENT OF FETAL CIRCULATION IN NORMAL EARLY-PREGNANCY, Fetal diagnosis and therapy, 12(3), 1997, pp. 178-184
A prospective cross-sectional study was performed in 81 consecutive pa
tients with low-risk singleton pregnancies and gestational age from 9
to 12 weeks of gestation in order to assess the fetal circulation at t
his stage of pregnancy. Patients' mean age was 29.8 +/- 3.8 (SD) years
. Mean gestational age was 10.5 +/- 1.1 weeks. All patients underwent
transvaginal color velocity imaging and pulsed Doppler ultrasound to o
btain the blood flow velocity waveforms (FVWs) from three fetal vessel
s: umbilical artery, abdominal aorta, and intracranial vessels. The pe
ak systolic velocity (PSV) and pulsatility index (PI) were analyzed. O
ptimal FVWs from each vessel were obtained in 98.8, 75.3 and 91.3% of
fetuses, respectively. Linear regression analysis showed a significant
progressive increase in PSV in the umbilical artery (r = 0.49, p < 0.
0001) and intracranial vessels (r = 0.36, p = 0.018)simultaneous to a
significant decrease in PI in both vessels (umbilical artery r = -0.37
, p = 0.0007; intracranial vessels r = -0.56, p < 0.0001). No signific
ant change was noted in the abdominal aorta in PSV (r = 0.06, p > 0.05
) or in PI (r = -0.15, p > 0.05).