What is the most significant risk factor for uterine rupture?

The most significant risk factor for uterine rupture is a previous cesarean delivery. This is primarily due to the formation of a scar on the uterus from the surgical incision made during the cesarean section. When a woman with a history of cesarean delivery goes into labor, there is a risk that the scar may weaken or not be able to withstand the contractions, leading to a rupture of the uterine wall. This potential for rupture increases significantly with the number of cesarean deliveries.

Other factors, such as macrosomia and multiple gestation, can contribute to complications during labor, but they do not directly impact the integrity of the uterine wall in the same way a previous cesarean does. Maternal obesity can also contribute to various obstetric complications, but it is not as closely linked to the specific risk of uterine rupture as a history of cesarean delivery.

Therefore, understanding the relationship between a prior cesarean and the associated risk of uterine rupture is crucial for assessing and managing labor and delivery in women with such a history.