Cord Clamping Time and Residual Placental Blood Volume in Elective and Emergency Caesarean Sections: An Observational Multicenter Study

Introduction: Placental transfusion at caesarean sections (CSs) is affected by different factors, such as cord clamping (CC) time and the cardiopulmonary transition of the infant. Measuring residual placental blood volume (RPBV) is one method to assess the magnitude of placental transfusion. The aim of this study was to evaluate the association between CC time and RPBV in elective and emergency CS, and to evaluate the association with other potential factors that may influence placental transfusion. METHODS: An observational multicenter study was conducted. Data were collected at elective and emergency CS at gestational ages ≥35+0 weeks, by direct observation and measurement of RPBV. RESULTS: A total of 185 subjects with CS were included (78 emergency CS). Birth weight was significantly associated to RPBV with a 13.0 mL increase of RPBV per kg birth weight. RPBV decreased by 4.7 mL/kg/min of deferred CC. Significant variables in the final adjusted model included CC time, indication for CS with a higher RPBV in emergency CS, and time to placental emptying. Non-significant variables included sex, form of anesthesia, cord gas blood sampling, and position of infant. CONCLUSION: RPBV, used as an inverse proxy for placental transfusion, was found to be associated with CC time at CS. The finding remained when adjusting for other variables that may influence RPBV and was particularly pronounced for emergency CS. .