Reference ranges for time-related analysis of ductus venosus flow velocity waveforms in singleton pregnancies.
OBJECTIVE
To investigate time intervals of ductus venosus (DV) flow velocity waveforms (FVW) in correlation to fetal heart rate and gestational age and to construct reference ranges for the second and third trimester. Furthermore, we investigate time intervals of FVW through the tricuspid valve.


METHODS
Flow velocity waveforms of the DV and through the tricuspid valve were recorded in 135 normal singleton fetuses between 17 and 38 weeks' gestation. Time intervals for systolic (S) and early diastolic (D) peaks were analyzed regarding acceleration time (acc-S for S, acc-D for D) and deceleration time (dec-S for S, dec-D for D), respectively. Similarly, time intervals for both peaks of right ventricular inflow were analyzed regarding acceleration time (acc-E for E-wave, acc-A for A-wave) and deceleration time (dec-E for E-wave, dec-A for A-wave), respectively.


RESULTS
In the DV, acc-D and dec-D increased significantly with gestational age. In tricuspid valve, acc-E and acc-A showed a significant increase with gestational age. All parameters except acc-S showed significant negative correlations with fetal heart rate.


CONCLUSIONS
With advancing gestational age, prolongation of the diastolic phase of DV-FVW and of the E-wave of tricuspid flow was observed, suggesting maturation of ventricular diastolic function. Time-related analysis of Doppler signals of DV-FVW may provide detailed insights into fetal cardiac function.
Department of Obstetrics and Gynecology, Osaka City University Graduate School of Medicine, Osaka, Japan.
Kayoko
K
Nakagawa
Daisuke
D
Tachibana
Hiroyuki
H
Nobeyama
Mitsuru
M
Fukui
Toshiyuki
T
Sumi
Masayasu
M
Koyama
Osamu
O
Ishiko
Kurt
K
Hecher
D000293:Adolescent; D000328:Adult; D001783:Blood Flow Velocity; D003971:Diastole; D005260:Female; D005333:Fetus / Q000098:blood supply*; D005865:Gestational Age; D006340:Heart Rate, Fetal; D006801:Humans; D008875:Middle Aged; D015588:Observer Variation; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D011263:Pregnancy Trimester, Third; D012016:Reference Values; D015203:Reproducibility of Results; D014261:Tricuspid Valve / Q000502:physiology; D016216:Ultrasonography, Prenatal / Q000592:standards*; D055815:Young Adult