Prenatal Diagnosis of a True Knot of the Umbilical Cord in Twins Pregnancy

Background: True knot of the umbilical cord is an uncommon finding, which is difficult to diagnose antenatally. The appropriate management of patients with a sonographically identified true knot is yet to be determined. Case: We present a twin pregnancy, in which antenatal diagnosis of a true knot of the umbilical cord was made at 33 weeks’ gestation. Fetal Doppler examination showed an absence of end diastolic flow in the umbilical artery of the second twin. Conclusion: The appropriate management of patients with a true knot identified prenatally is unclear. Once diagnosis is suspected, further fetal surveillance is warranted. Figure 1: Longitudinal sonogram of the abnormal portion of the umbilical cord demonstrates a bulge due to a loop of blood vessels. Scans show exaggerated looping of vessels. cord insertion of the second twin was revealed (Figure 1). On color Doppler this finding demonstrated a circular like pattern. Proximal and distal to this finding, the umbilical cord looked regular in appearance. Pulsed-wave Doppler examination revealed an intermittent absence end diastolic flow pattern in the umbilical artery of the second twin. Because of the early gestational age and the evidence of fetal wellbeing, expectant management was chosen, and the patient was admitted