True knots in the umbilical cord are rare, affecting approximately 1% of all pregnancies. The diagnosis may be missed antenatally during routine ultrasonography. Many known predisposing factors are associated with true knotting. In the majority of cases, it has no bearing on foetal outcome, but may rarely be linked to intra-uterine foetal death.
Keywords: 3D ultrasound; foetal demise; prenatal diagnosis; umbilical cord.