true knot


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true knot

, true knot of umbilical cord
actual intertwining of a segment of umbilical cord; circulation is usually not obstructed.
A knot of the umbilical cord at various places along its length and with varying degrees of tightness; oedema, grooving, narrowing, tightness, and differences of colour and/or diameter on the opposite sides of the knot may indicate vascular obstruction. In true knots, the placental disk is congested
Prognosis The consequences to the infant hinge on the tightness of the knot; tight knots cause foetal demise

true knot

True umbilical cord knot Neonatology A knot of the umbilical cord at various locations and degrees of tightness; edema, grooving, narrowing, tightness, and differences of color and/or diameter on the opposite sides of the knot may indicate vascular obstruction; the placental disk is congested Prognosis Consequences hinge on the tightness of the knot; tight knots cause fetal demise. Cf False knot.

true knot

A knot formed by the fetus slipping through a loop of the umbilical cord.
See also: knot
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References in periodicals archive ?
Some authors believe that 3D power sonography may be helpful in the diagnosis of the umbilical cord knots especially in the 3rd trimester.9 Ramon et al reported characteristics sonographic findings of this condition.10 Study done by Guzikowski et all to assess the role of 2D and 3D ultrasound for diagnosing true knot of the umbilical cord found it a useful modality.6
A comparison of umbilical cord blood gas values between newborns with and without true knots. Obstet Gynecol.
Four cases (17.39%) showed only two vessels, one case showed two true knots and this case also had evidence of chronic placental insufficiency in the form of a smaller placenta and smaller for gestational age fetus.