The aim of this study was to determine the first trimester human peripheral arterial and venous blood flow between 5 - 10 weeks of gestation. Two hundred twenty four women with singleton, uncomplicated pregnancies were prospectively studied with transvaginal ultrasound. Ductus venosus, umbilical artery waveforms and pulsatility indexes (PI) were assessed as well as the waveform of the umbilical...

Accumulating data on the human fetal circulation shows the similarity to the experimental animal physiology, but with important differences. The human fetus seems to circulate less blood through the placenta, shunt less through the ductus venosus and foramen ovale, but direct more blood through the lungs than the fetal sheep. However, there are substantial individual variations and the pattern ...

Rings of the umbilical end of the ductus venosus (the so-called sphincter) from nearterm fetal and newborn (1-3 days of age) lambs were studied in vitro at low (17-31 mm Hg) and high (504-705 mm Hg) P02. Tissues developed a modest contraction upon exposure to a high P02; however, this contraction generally was not sustained and tended to be greater in the fetus than in the newborn. In contrast,...

OBJECTIVE To determine whether assessment of ductus venosus flow at 11-13 weeks' gestation improves the detection rate of cardiac defects achieved by screening with nuchal translucency (NT) thickness. METHODS Prospective first-trimester screening for aneuploidies, including measurement of fetal NT and assessment of ductus venosus flow. The performance of different combinations of increased fe...

OBJECTIVE To evaluate the correlation between reversed a-wave in ductus venosus at 16-20 weeks' gestation and trisomy 21 and adverse perinatal outcomes. MATERIALS AND METHODS Our study included 174 pregnant women who were under follow-up at a tertiary center between May and September 2010. Ductus venosus Doppler (DVD) measurements were obtained throughout the 6-month period from women who und...

Placental dysfunction resulting in intrauterine growth restriction (IUGR) is a common complication of pregnany and severe IUGR, with ensuing fetal hypoxia is an important cause of perinatal mortality and morbidity. Doppler studies of fetal and maternal vessels are routinely used for fetal surveillance and alterations in fetal venous blood flow has been demonstrated as a late sign of fetal compr...

OBJECTIVE To determine the number of scans necessary for training sonographers to examine accurately the ductus venosus at 11 + 0 to 13 + 6 weeks' gestation. METHODS Ten sonographers with prior extensive experience in the measurement of nuchal translucency thickness were given practical training in the accurate assessment of the ductus venosus. They were then asked to examine the ductus venos...

AFTER the postnatal mammalian circulation has been established, blood flows serially from the systemic veins through the right side of the heart to the lungs, then to the left atrium and ventricle, which ejects the blood into the aorta to be distributed to the body, after which it returns to the systemic venous system. Apart from a small amount of coronary venous blood which enters the left ven...

AFTER the postnatal mammalian circulation has been established, blood flows serially from the systemic veins through the right side of the heart to the lungs, then to the left atrium and ventricle, which ejects the blood into the aorta to be distributed to the body, after which it returns to the systemic venous system. Apart from a small amount of coronary venous blood which enters the left ven...

OBJECTIVE To assess the possible role of Doppler ultrasound assessment of ductus venosus blood flow in screening for chromosomal abnormalities at 10-14 weeks of gestation. METHODS Ductus venosus flow velocity waveforms were obtained immediately before fetal karyotyping in 486 consecutive singleton pregnancies at 10-14 weeks of gestation. All cases were screened for chromosomal defects by a co...