[The effect of uterine incision expansion at caesarean delivery on perioperative haemorrhage: a prospective randomised clinical trial].

To determine if blunt or sharp expansion of the uterus at caesarean delivery is associated with increased maternal peripartum haemorrhage as estimated by the drop in hematocrit. Prospective randomised intention to treat clinical trial of women undergoing elective or urgent caesarean delivery at at least 36 weeks gestation. Two study groups were formed; after an initial hysterotomy which consisted in a transverse uterine incision of the lower segment, in the blunt group, the surgeon's indexes expanded the initial incision bilaterally and cephalad; in the sharp group, expansion of the initial incision was made using scissors. The primary outcome measure was the mean drop in hematocrit and p < 0.05 was considered significant. Three hundred women were randomised: 153 to the sharp group and 147 to the blunt group. The demographic and clinical characteristics of the two populations were similar. There were no statistically significant differences between the groups in estimated blood loss as assessed by the mean drop in hematocrit (%) (respectively 1.71 +/- 3.18 versus blunt group 1.91 +/- 3.28 p = 0.58 non significant). Our findings support that sharp or blunt expansion of hysterotomy during caesarean section equally affect blood loss as estimated by drop in hematocrit.