Umbilical cord loops are not usually considered to worsen obstetric outcome and rarely cause serious problems. The umbilical cord has a mean length of 55 cm (1) and the presence of loops is determined by the quantity of amniotic fluid and the amount of fetal movement. The prevalence of umbilical cord loops is 20 - 30% of all births for 1 loop and about 0.2% for 3 loops, (2) and increases with duration of pregnancy. (3) A nuchal cord usually appears when the umbilical cord is four-fifths as long as the fetus. (4) This condition usually does not influence the wellbeing of the newborn. (5) Transitory modifications of the fetal heart rate may be encountered, but the pH of the newborn's blood is not lowered. (6) Excessive uterine dynamics during birth, with continuous pressure on the umbilical cord, may be deleterious for the fetus. (7)
