Background: Umbilical cord knots may represent a hazard to the fetus, particularly as regards intrauterine death and fetal distress or asphyxia in labor. The object of this study was to analyze the impact of associated umbilical cord encirclements and cord length on fetal outcome and fetal weight deviation.
Methods: Among 22,012 births occurring in Akershus Central Hospital, there were 216 instances of umbilical cord knots. Fetal outcome, fetal weight deviation, associated umbilical cord encirclements and cord length were assessed.
Results: Neonates with a knotted cord are more often large-for-gestational age compared to other babies, and have longer umbilical cords. There is a 10 times higher chance of intrauterine fetal death with a knotted cord, but if this does not occur then there is no increased risk of obstetrical intervention and Apgar scores are the same as in other babies and other fetuses.
Conclusion: There is an association between umbilical cord knots and umbilical cord encirclements. Knotting of the cord is not by itself lethal. Pregnancies with knotted cords have characteristics different from those with ordinary umbilical cord encirclements.