Intra-operative haemorrhage by blunt versus sharp expansion of the uterine incision at caesarean delivery: a randomised clinical trial

Objective To determine whether the method used to expand the uterine incision for caesarean delivery affects the incidence of intra-operative haemorrhage. Design A prospective randomised study of women undergoing a low segment transverse caesarean delivery. Participants were assigned to have their uterine incision either sharply or bluntly expanded. Participants Between June 1998 and June 2000, 470 women drew assignments to the sharp expansion group and 475 to the blunt group. Results The maternal demographics of age, race, nulliparity, and body mass index as well as pre-operative haematocrit were similar between groups. Compared with the blunt group, the estimated blood loss (886 versus 843mL, P = 0.001), change in the mean haematocrit (6.1% versus 5.5%, P = 0.003), incidence of postpartum haemorrhage (13% versus 9%; relative risk = 1.23, 95% CI 1.03, 1.46) and need for a transfusion (2% versus 0.4%; relative risk = 1.65, 95% CI 1.25, 2.21) were significantly greater in the sharp group. Conclusion In caesarean delivery, sharply expanding the uterine incision significantly increases intra-operative blood loss and the need for subsequent transfusion.