True knot of umbilical artery

The relevance of CTG in a case of predaignosed true knot.   But the fact remains that considerable levels of apprehension often exist between the parents and the obstetricians when attempts are made at vaginal delivery.   Prenatal diagnosis of a true umbilical cord knot could be extremely difficult even with the use of ultrasonography for the reason that knots do not have characteristic prenatal ultrasonographic appearance. Furthermore, our current experience on true knot of the umbilical cord is limited to incidental observation. Therefore, there is a need for routine continuous monitoring of patients in labor using CTG.

The occurrence of true knot of the umbilical cord is very rare..   It may be defined as entwining of a segment of umbilical cord, usually without obstructing fetal circulation and commonly result from fetal slippage through a loop of the cord.

Although the reported incidence of true knots of the umbilical cords ranges from 0.3% to 2% certain factors have been noted to increase its predisposition. These include long umbilical cords, polyhydramnios, small size fetuses, male fetuses, gestational diabetes mellitus, monoamniotic twins, process of undergoing genetic amniocentesis  and multiparty

Most obstetricians are often concerned and perplexed about the exact time of formation of true knot of the umbilical cord. In general, the belief is that true knot of the cord is formed between 9 and 12 weeks of gestation. This early gestation is a period where the amniotic fluid volume is relatively larger. Paradoxically, there is reported evidence of knot formation of the umbilical cord when a woman is undergoing labor.

In the majority of cases, true knots of the umbilical cord occur without any clinical significance. However, in some rare occasion, there exists an association between umbilical cord knots and intrauterine fetal death as was seen in this case.