Umbilical cord coiling index is defined in terms of the number of 360-degree spiral course of umbilical vessels. This can be described in two main ways:
- the number of coils per one centimeter of length of cord.
- Normocoiled: one coil for a length of five centimeters.
- Hypercoiled: more than one coil per five centimeters.
- Hypocoiled: fewer than one coil per five centimeters.
- the total number of coils divided by the total length of the cord in centimeters.
- Normocoiled: 10th–90th percentile
- Hypercoiled: >90th percentile
- Hypocoiled: <10th percentile
This index plays an important role in predicting the pregnancy outcome and risk of low birth weight 2.
Hypocoiling can be associated with hypertensive disorders, placental abruption, preterm labor, oligohydramnios, and abnormal fetal heart rate.
Hypercoiling can be associated with maternal diabetes, polyhydramnios, cesarean delivery, congenital anomalies, and neonatal respiratory distress.
- 1. Tahmasebi M, Alighanbari R. Evaluation of umbilical cord thickness, cross-sectional area, and coiling index as predictors of pregnancy outcome. Indian J Radiol Imaging. 2011;21 (3): 195-8. doi:10.4103/0971-3026.85367 - Free text at pubmed - Pubmed citation
- 2. Chitra, T., Sushanth, Y. S., Raghavan, S.. Umbilical Coiling Index as a Marker of Perinatal Outcome: An Analytical Study. (2019) Obstetrics and Gynecology International. 2012: 213689. doi:10.1155/2012/213689 - Pubmed