TRANSVAGINAL COLOR DOPPLER ASSESSMENT OF FETAL CIRCULATION IN NORMAL EARLY-PREGNANCY

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).