The American College of Obstetricians and Gynecologists (ACOG) does not recommend routine ultrasound measurement of the lower uterine segment (LUS) thickness as part of the evaluation for trial of labor after cesarean delivery (TOLAC). ACOG Practice Bulletin No. 205 (2019) on Vaginal Birth After Cesarean Delivery does not include LUS measurement among its recommendations for TOLAC candidacy assessment. The guideline focuses on clinical factors such as type of prior uterine incision, number of prior cesarean deliveries, and other obstetric history to determine TOLAC candidacy, and emphasizes that most women with one previous low-transverse cesarean delivery should be counseled about and offered TOLAC. But what if you find a likely uterine window at the LUS? Does that mandate a repeat C-section? This topic comes from Serena, one of our podcast fami ...