The Sonographic Umbilical Cord Coiling in Late Second Trimester of Gestation and Perinatal Outcomes

Background: This study was conducted to determine whether or not the umbilical cord coiling index (UCI) during the late second trimester of gestation is associated with perinatal outcomes. Methods: This was a retrospective study of 251 pregnancies in which a fetal anatomic survey with a recorded UCI was performed at 22-28 weeks gestation. The subjects were divided into normocoiled, hypocoiled, and hypercoiled groups and compared perinatal outcomes. Results: Two hundred twenty-six patients were included. The incidence of preterm deliveries in hypocoiled group was 35%, which was significantly greater than the normocoiled groups (p=0.041). The incidence of neonates with low birth weights in the hypocoiled group was 36.4%, which was significantly greater than the normocoiled groups (p=0.044). In the hypocoiled group, 27.3% of newborns were admitted to the NICU which was significantly greater than the normocoiled and hypercoiled groups (p=0.041). After the adjustment by logistic regression analysis, only preterm delivery were significantly increased in hypocoiled group (OR=9.6, 95% CI=2.09-44.07). Conclusion: The hyporcoiling of the umbilical cord during the late second trimester of pregnancy suggest that the risk for preterm delivery is high, consequently the delivery of low birthweight neonates is high, and the admission to the neonatal intensive care unit is increased.