The association between umbilical cord abnormalities and the development of non-reassuring fetal heart rate leading to emergent cesarean deliveries.

OBJECTIVE: To study the contribution of umbilical cord (UC) abnormalities in emergent cesarean deliveries (ECDs) for non-reassuring fetal heart rate (NRFHR) and to explore their association with placental histopathology and neonatal outcome.

STUDY DESIGN: Data from 530 ECDs for NRFHR were reviewed for the occurrence of UC abnormalities. Those included the presence of UC entanglements, the number and location of loops, true knots and short cord (<50 cm). Multiple UC entanglements were defined as ⩾ 2 UC loops. Results were compared with 530 vaginal deliveries (VD group) matched for maternal age, parity and gestational age. Additionally, we compared neonatal outcome and placental histopathology in cases of ECDs with a single vs multiple UC entanglements. Neonatal outcome consisted of low Apgar score (⩽ 7 at 5 min), cord blood pH ⩽ 7.1 and composite neonatal outcome that was defined as one or more of respiratory distress, necrotizing enterocolitis, sepsis, transfusion, ventilation, seizure, hypoxic-ischemic encephalopathy, phototherapy or death. Placental lesions were classified as: lesions related to maternal vascular supply, lesions related to fetal vascular supply (consistent with fetal thrombo-occlusive disease), and maternal and fetal inflammatory responses.

RESULTS: UC entanglements, true knots and short cords were all more common in the ECD group compared with the VD group, P<0.001, P=0.002, P=0.004, respectively. The rate of one loop entanglement did not differ between the groups. The rate of multiple UC entanglements was higher in the ECD group compared with the VD group, 20.6% vs 6.4%, respectively, P<0.001. ECDs with multiple compared with single UC entanglement had higher rate of adverse neonatal outcome, P=0.031, and more placental fetal vascular lesions 19.3% vs 8.1%, P=0.027, respectively.

CONCLUSION: Multiple UC entanglements, true knots and short cords were more common in ECDs for NRFHR, suggesting their role in the development of fetal placental vascular lesions and adverse neonatal outcome.