Trial of labor after 2 previous cesareans: a multicenter study

Area of Science:

• Obstetrics and Gynecology
• Maternal-Fetal Medicine
• Reproductive Health

Background:

• Trial of labor after cesarean (TOLAC) following two prior cesarean deliveries is associated with reduced vaginal birth success and increased adverse obstetrical outcomes compared to TOLAC after one prior cesarean.
• Understanding factors influencing TOLAC success in women with two prior cesareans is critical for informed clinical decision-making.

Purpose of the Study:

• To identify and analyze factors associated with failed trial of labor after cesarean (TOLAC) in women with two previous cesarean deliveries.
• To compare maternal and neonatal characteristics between successful and failed TOLAC groups in this specific obstetric population.

Main Methods:

• A multicenter retrospective cohort study was conducted involving women with singleton pregnancies attempting TOLAC after two prior cesarean deliveries (2003-2021).
• Data on labor, maternal, and neonatal characteristics were collected and compared between women with failed and successful TOLAC.
• Univariate and multivariable analyses, including adjusted odds ratios with 95% confidence intervals, were performed to identify significant factors.

Main Results:

• Out of 1181 women, 82.4% achieved vaginal birth after cesarean (VBAC).
• Failed TOLAC was linked to higher maternal and neonatal morbidities, longer interpregnancy/interdelivery intervals, lower gravidity/parity, no prior VBAC, smoking, earlier gestational age, late preterm delivery, lower cervical dilation on admission, no epidural use, and lower birthweight.
• Multivariable analysis identified late preterm delivery (aOR 3.79) and cervical dilation <3 cm on admission (aOR 2.58) as significant predictors of failed TOLAC.

Conclusions:

• In women with two prior cesarean deliveries, attempting TOLAC during the late preterm period with cervical dilation less than 3 cm (latent phase) increases the risk of failure.
• These findings highlight the importance of cervical dilation and gestational age at admission as critical factors in predicting TOLAC success in women with multiple prior cesareans, potentially influencing decisions regarding intrapartum cesarean delivery.