목적: The aim of this study was to investigate the association between the umbilical cord characteristics of antepartum ultrasonography(UCCAU), measured after 26 weeks, and adverse intrapartum and perinatal outcome. 방법: This was a retrospective cross-sectional study involving 250 women who had delivered at term in a tertiary medical center, from November 2014 to November 2015. Fetuses with prenatally detected abnormality were excluded. UCCAU including umbilical cord diameter(UCD), umbilical artery diameter(UAD), umbilical vein diameter(UVD) and their cross-sectional area were compared according to gestational age. And data was analyzed whether UCCAU were correlated with intrapartum and perinatal outcomes. 결과: The diameter and whole area of umbilical cord formed a plateau at 29 weeks gestation. We found out that the cross-sectional area of umbilical cord and Wharton’s jelly positively correlated with the birth weight (p<0.001) and negatively correlated with non-reassuring fetal heart rate (p<0.05). In the small cord group that corresponds to less than ten percentile of cross-sectional area of umbilical cord, newborn had lower birth weight (2681±403gm vs 3342±512gm, p<0.05) and the rate of neonatal intensive care unit admission were higher than the control group (38.5% vs.17.3%, p<0.05). No statistically significant difference of the rate of intrapartum cesarean section was found between two groups. But most common cause of the emergent cesarean section in the small cord group was non-reassuring fetal heart rate pattern(70%) while that in control group was abnormal labor including prolonged latent phase and arrest of descent (67.1%). 결론: This study suggests that small cross-sectional area of umbilical cord, measured after 29 weeks, is associated with a greater risk of intrapartum cesarean section for fetal compromise and adverse perinatal outcomes.