Jc. Collins et al., PRENATAL OBSERVATION OF UMBILICAL-CORD ABNORMALITIES - A TRIPLE KNOT AND TORSION OF THE UMBILICAL-CORD, American journal of obstetrics and gynecology, 169(1), 1993, pp. 102-104
Umbilical cord abnormalities can be observed with ultrasonography. Two
cases are described where a triple knot and torsion of the umbilical
cord are observed. These cases allow the elucidation of the mechanics
of formation of a triknot and torsion abnormality.