Accurate diagnosis of umbilical circulation

Umbilical arterial flow velocity has been widely used for the estimation of fetal status. This is clinically useful, but affected by physiological characteristics or other factors such as maternal drug administration. Otherwise, umbilical venous pulsation is also used for fetal estimation. But, this particular pattern appeared not only from fetal cardiac problems, but from umbilical cord characteristics. We summarized the various factors which affect the umbilical circulation.