Cardiac Adaptation and Preferential Streaming in Fetuses with Multiple Nuchal Cords

The echocardiographic monitoring of a fetus with multiple nuchal cords around the fetal neck is important as it may result in cardiac remodeling and preferential streaming, thus affecting the condition of the fetus. The main aim of our study was to assess whether the collision of the umbilical cord around the fetal neck can lead to discrepancies in the size of the pulmonary artery and the aorta in the three-vessel view and to an increase in the size of the heart, which may result from the compression of the carotid arteries caused by the umbilical cord wrapping around the fetal neck. A total number of 854 patients were included in this study and divided into three groups. Group A (control group) included 716 fetuses (84%) without the umbilical cord around the fetal neck. Group B (study group B) included 102 fetuses (12%) with one coil of the umbilical cord around the fetal neck. Group C (study group C) included 32 fetuses (4%) with two coils of the umbilical cord around the fetal neck. The range of the gestational age of the patients considered for this study was 27-40.2 weeks based on the ultrasound biometry and was not statistically different between the analyzed groups A, B and C (p > 0.05). The Pa/Ao index was calculated by dividing the value of the width of the pulmonary artery (in mm) to the width of the aorta (in mm) measured in the ultrasound three-vessel view. We found that fetuses that the fetuses with one and two coils of the umbilical cord around the neck showed significantly higher values of the width of the pulmonary trunk with the unchanged value of the aorta width. Therefore, we also observed significantly higher values of the ratio of the pulmonary trunk to the aorta for the fetuses wrapped with the umbilical cord around the neck compared with the control group without the umbilical cord around the neck (. Moreover, in the fetuses with one and two coils of the umbilical cord around the fetal neck, an increased amount of amniotic fluid was observed, whereas larger dimensions of CTAR in the fetuses with two coils of the umbilical cord around the neck were present (p < 0.05). The wrapping of the fetus with the umbilical cord around the fetal neck may induce the redistribution of blood flow, leading to fetal heart enlargement and disproportion and may be the cause of polyhydramnios.