Sonographic evaluation of umbilical cord insertion with umbilical coiling index

Purpose. The aim of this study was to investigate the association between u mbilical cord hypocoiling and abnormal placental insertion of the umbilical cord. Methods. Umbilical coiling was measured by sonography in 253 pregnant women in their second or third trimester. An umbilical coiling index, defined he re as the reciprocal of the length of 1 umbilical vascular coil, of less th an 0.1 was considered hypocoiled. The distance from the placental edge to t he insertion of the umbilical cord was measured after delivery, and the res ults were used to classify cord insertion as normal, marginal, or velamento us. Results. Cord insertion was abnormal in 66.7% of the fetuses with umbilical hypocoiling but in only 1.3% of those whose coiling index was greater than or equal to 0.1 (p < 0.05). Conclusions. Hypocoiling of the umbilical cord was highly associated with a bnormal cord insertion. The presence of a hypocoiled umbilical cord may ind icate the presence of abnormal cord insertion and thus may be useful for ob stetric management. (C) 1999 John Wiley & Sons, Inc. J Clin Ultrasound 27:3 41-344, 1999.