Risk factors and perinatal outcomes associated with umbilical cord prolapse.

Objective: To utilize infant outcomes and to identify risk factors associated with umbilical cord prolapse.
Materials and Methods: Birth records of 80 cases with umbilical cord prolapse and 800 randomly selected controls were reviewed retrospectively. Statistical analysis was performed using logistic regression models.
Results: Prolapse of the umbilical cord complicated 0.47% (n=80) of all deliveries included in the study (n=16,874). Multiparity was more common in patients with umbilical cord prolapse (63.8-49.4%, P=0.014). Umbilical cord prolapse occurred in breech presentation in six cases (7.5%) and in transverse presentation in three of the cases (3.8%). The occurrence of breech presentation among the control cases was 1.0% and of the transverse lie was 0.1% (P<0.001). Fetuses with umbilical cord prolapse had lower fetal weight; particularly, fetal weight less than 2,500 g was a significant risk factor (3-2.4%, P<0.001). We also found that spontaneous rupture of membranes (OR=8.93; 95%, CI=4.16-19.14), Bishop score greater than 8 (OR=5.48; 95%, CI=3.21-9.34), and polyhydramnios (OR=21.0; 95%, CI=11.4-38.7) were risk factors for umbilical cord prolapse. The newborns that were delivered after umbilical cord prolapse graded lower Apgar scores less than 7 at 5 min (6.3-1.4%, P=0.002).
Conclusion: Abnormal fetal presentation, multiparity, low birth weight, prematurity, polyhydramnios, and spontaneous rupture of membranes, in particular with high Bishop scores, are risk factors for umbilical cord prolapse. Early amniotomy increases the variable decelerations and hence increases the rate of cesarean section because of fetal distress, but it may prevent pregnant women from umbilical cord prolapse, which has a high mortality rate. However, large randomized trials are needed to prove that early amniotomy decreases the incidences of umbilical cord prolapse.