Sonography of lower uterine segment thickness and prediction of uterine rupture.

Abstract

Sonographic evaluation of the lower uterine segment was undertaken to study the degree of thinning and, thus, to predict uterine rupture. However, the best measuring technique and recommended cutoff values remain controversial. Sonographic evaluation of the lower uterine segment at 36 weeks of gestation in a 31-year-old patient with prior low transverse cesarean delivery revealed a full thickness of 3.6 mm and a myometrial layer of 1.1 mm. Nevertheless, the patient experienced a large uterine rupture during a trial of labor at term. In this case, there was a discrepancy between the full thickness and the myometrial layer, which could be representative of the lower uterine segment resistance. Such a case emphasizes the need for a consensus on sonographic measuring techniques for the prediction of uterine rupture.