True Umbilical Cord Knot without Adverse Perinatal Outcome: A Brief Review

Abstract

True umbilical cord knots are not a common occurrence, however when they do present, it is ironic that despite having availability of antenatal ultrasound, they are not diagnosed antenatally most of the time, due to cord length and loops of cord making visibility poor. However with 4 dimension ultrasound and serial doppler study there can be better pick up rate. There is controversy around risks with true knots and cases of meconium stained liquor, low Apgar scores, hypoxic ischemic encephalopathy, other neonatal complications necessitating neonatal intensive care unit admission and fetal still birth have been reported. The umbilical cord attaches to the placenta and transfers blood, oxygen and nutrition to the fetus. A true umbilical cord knot happens when the cord loops over itself with fetal movements, a tight knot can impair the fetal circulation and lead to fetal hypoxia. In such a situation, fetal surveillance shows sub optimal cardiotocograph tracing, and when the patient is taken for emergency cesarian section, a tight umbilical cord knot is seen, which was causing fetal hypoxia. Certain conditions are more predisposed for true knots such as polyhydramnios, longer length of the cord, smaller than average size fetus, monoamniotic twins and multiparity. Our case report presents a true umbilical cord at an elective cesarian section in a primigravida. The patient had an uneventful pregnancy with regular fetal surveillance through ultrasound and doppler scans and fetal heart tracing. An elective cesarian section was performed at 38 weeks at patient’s request and at the time a nuchal cord and true umbilical cord was noted.