SUMMARYThe aim of this study was to determine the relationship between the number of coils in the umbilical cord and perinatal outcome. The umbilical cords and delivery records of 147 liveborn neonates were prospectively studied. The umbilical coiling index (UCI) of each cord was calculated by dividing the total number of complete umbilical vascular coils by the umbilical cord length. Subjects with UCIs below the 10th percentile, above the 90th percentile, and between the 10th and 90th percentiles were defined as hypocoiled, hypercoiled, and normocoiled, respectively. Several different parameters were used to measure neonatal outcome. The mean UCI was 0.20 ± 10 (SD). No relationship was noted between UCI and maternal age, gravidity, parity, oligohydramnios, or birth weight. When we compared the hypocoiled group (n=30) with the normocoiled group (n=87), we detected a statistically significantly higher incidence of meconium staining, interventional delivery, apgar scores, fetal blood pH and intrapartum fetal heart rate disturbances. As a result, we concluded that the UCI has a strong relationship with perinatal outcome and may be used antenatally as a marker for identifying the fetus at risk.