The WILDCARD: LUS Window on Prenatal Sono, TOLAC?

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 family members. Listen in for details.

1. Dr. Chapa’s Clinical Pearls, Dec 31., 2023: LUST FOR TOLAC; and follow up episode Jan 15, 2024

2. ACOG Practice Bulletin No. 205: Vaginal Birth After Cesarean Delivery. Committee on Practice Bulletins—Obstetrics Obstetrics and Gynecology. 2019;133(2):e110-e127. doi:10.1097/AOG.0000000000003078.

3. Rozenberg P, Sénat MV, Deruelle P, et al. Evaluation of the Usefulness of Ultrasound Measurement of the Lower Uterine Segment Before Delivery of Women With a Prior Cesarean Delivery: A Randomized Trial. American Journal of Obstetrics and Gynecology. 2022.

4. Swift BE, Shah PS, Farine D. Sonographic Lower Uterine Segment Thickness After Prior Cesarean Section to Predict Uterine Rupture: A Systematic Review and Meta-Analysis. Acta Obstetricia Et Gynecologica Scandinavica. 2019.

5. McLeish SF, Murchison AB, Smith DM, et al. Predicting Uterine Rupture Risk Using Lower Uterine Segment Measurement During Pregnancy With Cesarean History: How Reliable Is It? A Review. Obstetrical & Gynecological Survey. 2023.

6. Jastrow N, Demers S, Chaillet N, et al. Lower Uterine Segment Thickness to Prevent Uterine Rupture and Adverse Perinatal Outcomes: A Multicenter Prospective study.

7. American Journal of Obstetrics and Gynecology. 2016.

8. Guerby P, Bujold E, Chaillet N. Impact of Third-Trimester Measurement of Low Uterine Segment Thickness and Estimated Fetal Weight on Perinatal Morbidity in Women With Prior Cesarean Delivery. Journal of Obstetrics and Gynaecology Canada. JOGC. 2022.