Umbilical Cord Knots And Encirclements

EDITORIAL COMMENT: This paper confirms that a long umbilical cord is more likely to become knotted or encircle the fetal neck. Because these cord complications seldom harm the fetus, clinicians should look for other causes of birth asphyxia or ‘unexplained’ stillbirth. Greater awareness of spontaneous fetomaternal haemorrhage may eventually lead to diagnosis sufficiently early to permit effective treatment (Fliegner JRH, Fortune DW, Barrie JV. Occult fetomaternal haemorrhage as a cause of fetal mortality and morbidity. Aust NZJ Obstet Gynaecol 1987; 27: 158–161). Other circumstances where cord entanglements may distant the clinician away from the real cause of corrective fetal compromise include intrauterine infection, maternal drug therapy, haemorrhage from vasa praevia and diaphragmatic hernia. Summary: Although cord knots and/or encirclements account for 1 in 10 stillbirths of infants weighing 2,500 g or more, no problem due to this cause was encountered in a prospective study of 1,115 vaginal deliveries. In this study there were 6 cases of cord knot (0.5%) and 158 of cord encirclement (14.2%). The range of cord length was 27 — 122 cm, the 10th, 50th and 90th percentiles being 40, 52 and 69 cm respectively. In this study there was no clinical warning (fetal distress) of cord encirclement or knot during pregnancy, labour or delivery.