Blood flow in ductus venosus in early uncomplicated pregnancy.
The ductus venosus is the very important part of fetal venous circulation. It plays a central role in return of venous blood from the placenta. This unique shunt carries well-oxygenated blood from the umbilical vein through the inferior atrial inlet on its way across the foramen ovale. Using Doppler ultrasound, it is possible to assess the blood flow in fetal vessels including ductus venosus. It is observed, in animal and human studies, that the typical waveform for blood flow in ductus venosus in early pregnancy can be different depending on numerous conditions e.g. fetal karyotype. This study is performed to assess the physiologic parameters of blood flow in ductus venosus in uncomplicated early pregnancy.


METHODS
404 women were examined between 11+0 and 13+6 weeks (+ days) of gestation by ultrasound. Fetal crown-rump length (CRL) was measured to assess the gestational age. The assessment of risk of fetal abnormalities was based on nuchal translucency (NT) measurement. The ductus venosus blood flow with color and spectral Doppler was obtained in all patients. The following features were assessed: pulsatility index (PI), and direction of flow (positive/negative) during atrial contraction (wave A). All cases were followed up to 22 weeks of gestation when the control scan was performed.


CONCLUSIONS
30 cases were excluded from the uncomplicated group due to: high risk of fetal abnormalities, fetal loss, confirmed fetal abnormalities and utero-placental pathology. 374 women were considered as uncomplicated pregnancy. In both uncomplicated and complicated groups the mean values for pulsatility index (PI) were established. The mean PI value in uncomplicated pregnancies was: 0.91 (SD +/- 0.32). No significant differences between groups were noticed. In 370 cases of uncomplicated pregnancy the A wave direction was positive but in 1.1% of cases the reverse flow in atrial contraction was observed.
Sodowski
Krzysztof
K
Obstetrics and Gynecology Clinic Ruda Slaaka, Silesian Medical Academy Katowice, Poland.
Cnota
Wojciech
W
Czuba
Bartosz
B
Borowski
Dariusz
D
Wielgos
Miroslaw
M
Kaminski
Pawel
P
Jaczyńska
Renata
R
Włoch
Agata
A
Kuka
Dorota
D
Zwirska-Korczala
Krystyna
K
Szaflik
Krzysztof
K
D001783:Blood Flow Velocity; D005260:Female; D005318:Fetal Heart / Q000502:physiology*; D005333:Fetus / Q000098:blood supply*; D005865:Gestational Age; D006801:Humans; D011247:Pregnancy; D012016:Reference Values; D012039:Regional Blood Flow; D018617:Ultrasonography, Doppler, Pulsed; D016216:Ultrasonography, Prenatal / Q000379:methods; D014471:Umbilical Veins / Q000000981:diagnostic imaging / Q000502:physiology*; D014682:Vena Cava, Inferior / Q000000981:diagnostic imaging / Q000502:physiology*