Effects of bleeding on uteroplacental, umbilicoplacental and yolk-sac hemodynamics in early pregnancy.

OBJECTIVE: To determine the influence of vaginal bleeding with or without a persisting subchorionic hematoma on uteroplacental, umbilicoplacental and yolk-sac hemodynamics in early pregnancy. DESIGN: Twenty-six consecutive patients with vaginal bleeding entered this longitudinal study 1-3 days after the beginning of vaginal bleeding and were re-examined every 1-2 weeks. In three cases vaginal bleeding occurred at the 5th completed gestational week, in 13 at the 7th week, in nine at the 8th week and in one case at the 10th week. A subchorionic hematoma was identified in one case at the 5th week, in nine cases at the 7th week, in nine cases at the 8th week, and in seven cases at the 10th week. Four pregnancies ended in miscarriage. Blood velocity waveforms of uterine, arcuate, radial, spiral, umbilical, chorionic and yolk-sac arteries were obtained by transvaginal pulsed Doppler ultrasound and peak systolic velocities, time-averaged maximum velocities and pulsatility indices were calculated. The results were compared with our earlier observations in normal pregnancy obtained with a similar study protocol. RESULTS: At the 7th week, radial artery pulsatility-index values (mean (SD)) were higher in pregnancies with vaginal bleeding (1.84 (0.59); P = 0.04) and in pregnancies with a subchorionic hematoma (1.96 (0.63); P = 0.03) than in normal pregnancies (1.40 (0.46)). The pulsatility-index values of uterine, arcuate, spiral, umbilical and chorionic arteries did not differ between the groups. Vaginal bleeding with or without a subchorionic hematoma at the 8th week did not affect any of the measured parameters. Persistence of the subchorionic hematoma until the 10th week did not affect uterine, arcuate, radial, spiral, umbilical or chorionic artery hemodynamics. Yolk-sac hemodynamic parameters did not differ between the groups. CONCLUSIONS: Vaginal bleeding with or without a subchorionic hematoma is associated with increased radial artery impedance at the 7th week of pregnancy. Persistence of the subchorionic hematoma does not affect utero- and umbilicoplacental circulation.