American journal of perinatology

Unintended extension of the lower segment uterine incision at cesarean delivery: a randomized comparison of sharp versus blunt techniques.

PMID 24347261


This study compared two methods of expanding the uterine incision at the time of cesarean delivery, which is associated with the risk of unintended extension. This randomized trial included 1,076 women who underwent elective cesarean delivery. The primary outcome measure was the incidence of unintended extension related to the method used for expanding the uterine incision. Participants in both groups (blunt vs. sharp) had similar demographic and clinical characteristics. The incidence of unintended extension (8.8% vs. 4.8%; p = 0.009), mean estimated blood loss (853.67 ± 42 mL vs. 664.80 ± 38 mL; p = 0.001), and blood loss >1000 mL (11.4% vs. 6.8%; p = 0.009) was significantly higher in the sharp group compared with the blunt group. No difference in transfusions (7.5% vs. 6.3%; p = 0.440) or the need for additional supertonic agents (16% vs. 12.9%; p = 0.144) was noted. Sharp expansion of the uterine incision was related to a higher risk of unintended extension and maternal blood loss. Because blunt expansion is associated with a lower risk for unintended extension and maternal blood loss, it should be the first option during elective cesarean delivery.