Diagnosis of the venous duct in fetuses of the early period of human ontogeny

Abstract

To carry out an analysis of data from the world literature regarding the role of Doppler assessment of blood flow in the venous duct of the fetus in chromosomal abnormalities in the first trimester of pregnancy, as a marker – the spectral form of wave blood flow and its pulsation, which is generated by changes in the pressure and volume of blood to the heart of the fetus. Prenatal diagnosis of venous blood flow makes it possible to assess the state of the fetal cardiovascular system. Blood flow in the ductus venosus is an integrative indicator that reflects the formation of blood circulation of both the uteroplacental and placental-fetal components of gestational hemodynamics during physiological and complicated pregnancy. The performance of this test is 63%, and in combination with the assessment of the thickness of the clavicle – 89.1%. When reverse values of blood flow in the ductus venosus are detected in the phase of contraction of the atrium and dilated cervical space, it is necessary to carry out karyotyping to rule out chromosomal abnormalities. Dopplerography allows us to objectively assess the functioning state of the fetus during physiological and complicated pregnancy based on the study of the state of blood flow in the vessels of the placenta, in the middle cerebral artery, thoracic aorta, renal arteries, inferior vena cava and venous duct. The spectrum of venous blood flow reflects changes in volume and pressure in the atria during the cardiac cycle. With normal fetal development, blood flow in the venous duct has a pulsating character in the form of a unidirectional three-phase curve that corresponds to different periods of the cardiac cycle. The spectrum of normal blood flow in the venous duct in a healthy newborn has a biphasic curve, with the direction from the portal sinus to the inferior vena cava. During three weeks of regular examinations in most babies, obliteration of the venous duct occurs, and the ductus turns into a venous connection. Two-dimensional echocardiogram, color and pulsed dopplerography allow recording the waveforms of blood flow in several structures of the heart. Doppler analysis of blood flow in the venous duct is important to perform in fetuses of the first trimester, as it increases the sensitivity of the combined test in assessing the risk of chromosomal disorders. Assessment of blood flow in the ductus venosus provides an understanding of physiological and pathological processes in the fetal body and identifies fetuses that are prone to or at risk of disease.