Quantifying Maternal Blood Loss from the Hysterotomy at Cesarean Delivery

Background: With newer protocols, such as delayed cord clamping, becoming routine practice, determining the potential maternal consequences is important. In particular, establishing normative values for blood loss from the hysterotomy would be helpful in addressing techniques to minimize total blood loss for cesarean deliveries. Objective: Blood loss from the hysterotomy during cesarean delivery has not been reported using quantitative methods. We aimed to quantify the rate of blood loss during cesarean delivery from the hysterotomy between creation and closure. Methods: This single center, prospective, case series was collected in 2018. Women with singleton pregnancies undergoing cesarean delivery at ≥37 0/7 weeks at Brigham and Women’s Hospital were included. Delayed cord clamping was performed which allowed for quantification of blood loss through gravimetric methods and descriptive statistics were performed. Results: Twenty patients were included. The mean hysterotomy closure delay for cord blood collection was 47 seconds (SD 10.2) and the mean maternal blood volume collected was 110.8 mL (SD 53.4 mL). Blood loss per minute was calculated with a median of 150 mL/minute (IQR 88.8 mL, 95% CI 109.2 - 190.4 mL). The mean post-operative hematocrit drop was 4.4%, and there were no blood transfusions. There was a single hysterotomy extension and a quantified blood loss of 413 mL per minute. Conclusion: We found a mean blood loss of 150 mL/min without hysterotomy extension. With a hysterotomy extension, the blood lost per minute was more profound. This normative data can be helpful for surgical planning with regards to delayed cord clamping or cord blood collection for banking.