Uterine Rupture Risk Rises in Modern TOLAC Cases

TOPLINE: 

National rates of uterine rupture in trial of labor after cesarean (TOLAC) increased from 0.20% in 2010 to 0.37% in 2022, with an annual percentage increase of 6.2%. Among 1,016,073 deliveries analyzed, 2888 uterine ruptures occurred, representing 0.28% of cases.

METHODOLOGY:

• Researchers conducted a repeated cross-sectional analysis using natality files from the National Vital Statistics System, examining data from 2010 to 2022.
• Analysis included 1,016,073 singleton, cephalic, term pregnancies with one or two prior cesarean deliveries undertaking TOLAC.
• Primary outcome measure was uterine rupture, defined as a ruptured uterus recorded for maternal morbidity on the birth certificate.
• Secondary outcomes encompassed unplanned hysterectomy, maternal blood transfusion, maternal intensive care unit admission (available from 2015), neonatal intensive care unit admission, and neonatal death.

TAKEAWAY:

• Uterine rupture rates showed a significant increase over the study period (average annual percent change, 6.2%; 95% CI, 4.3%-8.7%).
• Maternal blood transfusion rates demonstrated an upward trend (annual percentage change, 7.17%; 95% CI, 6.31%-8.02%).
• Maternal intensive care unit admission rates increased (annual percentage change, 3.32%; 95% CI, 1.89%-4.79%).
• Neonatal death rates decreased over time (annual percentage change, -6.4%; 95% CI, -8.5% to -3.8%), while neonatal intensive care unit admission rates increased (average annual percent change, 1.8%; 95% CI, 1.3%-2.2%)

IN PRACTICE:

“The uterine rupture rate (0.28%) is lower than that found in prior studies but is aligned with other recent data. Similarly, rates of maternal ICU admission, NICU admission, and transfusion increased, whereas the rate of neonatal death decreased. These findings extend our understanding of risks related to undertaking TOLAC in the modern era,” wrote the authors of the study.

SOURCE:

The study was led by Lillian H. Goodman, MD, MPH, University of Utah Health in Salt Lake City. It was published online in Obstetrics & Gynecology.

LIMITATIONS: 

According to the authors, limitations include potential misclassification and underascertainment from the use of birth certificate data, and the absence of granular clinical details around labor management. Additionally, natality data does not differentiate between intrapartum uterine rupture and incidental dehiscence identified at the time of surgery.

DISCLOSURES:

Torri D. Metz, MD, disclosed receiving royalties from UpToDate for topics on TOLAC. Her institution received funding from Pfizer for studies on respiratory syncytial virus vaccine trials and Paxlovid in pregnancy. She also reported being a site principal investigator for Moderna’s respiratory syncytial virus vaccine trial and serving on the Society for Maternal-Fetal Medicine Board of Directors. The other authors reported no potential conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.