Prior Cesarean Section Surgical Characteristics and Subsequent Uterine Rupture [30P

Abstract

INTRODUCTION: To determine if prior Cesarean surgical characteristics that may compromise healing are associated with an increased risk of subsequent uterine rupture. METHODS: Retrospective case-control study matching women with uterine rupture to randomly selected controls (1:3) based on number of prior Cesarean deliveries (CD) and labor at the time of current CD. A multivariable logistic regression was performed focusing on hemorrhage and surgical procedures at prior CD, including all factors that differentiated the groups plus maternal age. RESULTS: 60 women with uterine rupture were matched to 180 controls. Case patients were more often white (P=.005) and had a higher rate of prior pelvic surgeries (P=.002). With regards to the prior CD, case patients had increased rates of classical incisions (P=.0006), labor (P=.001), and endometritis (P=.01). Case subjects had higher rates of prior postpartum hemorrhage (PPH) (9% vs. 3%, P=.04), and more prior hysterotomy extension (23% vs 6%, P=.0009), but did not differ in the rates of prior compression suture, arterial ligation, or uterine artery embolization (5% composite rate for each group). In multivariable regression analysis, prior uterine extension remained significantly associated with rupture (aOR 2.05, 95% CI 1.48–5.69), while PPH (aOR 1.31, 95% CI 0.15–4.20) was not. CONCLUSION: A prior history of hysterotomy extension is associated with an increased risk of subsequent uterine rupture. This may reflect vascular disruption or diminished integrity of the lower uterine segment. Prior surgical details should be reviewed in counseling patients in future pregnancies.