Umbilical Coiling Index, A Predictor of Perinatal Outcome

Abstract

Umbilical cord (UC) represents the “life source”, or the “entry and exit” point of humans which is the only source of energy. It is essential for the development, well-being, and survival of the nourishing baby. The characteristic of the coiling of the umbilical cord makes the cord a structure that is both flexible and strong and provides resistance to external forces which could compromise the blood flow to the foetus. UC is vulnerable to kinking, compressions, traction, and torsion, which may affect the intrauterine life and perinatal outcome due to coiling. One complete spiral of 360º of the umbilical vessels around each other is defined as Umbilical Coil. Abnormal coiling is defined as UCI less than the 10^th percentile (i.e., Hypocoiled cord), UCI more than the 90^th percentile (i.e., Hypercoiled cord), and the UCI between 10^th and 90^th percentile is Normocoiled cord. According to the literature studies, hypercoiled cords are usually associated with intrapartum foetal acidosis and asphyxia, foetal growth restriction, vascular thrombosis, and cord stenosis while the increased incidence of foetal demise, intrapartum FHR deceleration, low APGAR scores, preterm delivery, chorioamnionitis, structural and chromosomal abnormalities, and operative delivery have been associated more with hypocoiled cords. Hence, if the umbilical coiling index can be measured reliably in utero by ultrasound antenatally, then in future, it might become a promising prognostic marker for a better pregnancy and adverse foetal outcome.