Assessment of the rate of uterine rupture at the first prenatal visit: A preliminary evaluation

Abstract

Objective. To quantify the risk for symptomatic uterine rupture during a trial of labor after prior cesarean delivery based on factors that can be ascertained during early pregnancy.

Methods. From all trials of labor over a 12-year period, we determined those factors associated with an increased or decreased risk for uterine rupture and assigned scores. The following numerical scores were used: 2 points for ≥ 2 prior cesarean scars, 1 point for interdelivery interval ≤ 18 months, 1 point for maternal age of 30–39 years, 2 points for maternal age ≥ 40 years, minus 1 point for women with prior vaginal delivery and one prior cesarean.

Results. There were 40 uterine ruptures in 4383 trials of labor (0.91%). Overall, the rate of uterine rupture varied by score: −1–0.26% (1/391), 0–0.25% (4/1613), 1–1.11% (21/1894), 2–2.43% (9/370), 3–3.70% (4/108), and 4–14.29% (1/7), p = .001.

Conclusions. The rate of symptomatic uterine rupture during a trial of labor varies greatly depending on easily identified risk factors, and is low for women without risk factors.

Keywords:

• Uterine rupture
• trial of labor