Trial of labor after cesarean in women with hypertensive disorders and no prior vaginal delivery.

Key Message: Trial of labor among women who never delivered vaginally with hypertensive disorder is associated with nearly half the success rate of the general population.

Purpose: To study the trial of labor after cesarean (TOLAC) among women with hypertensive disorders and no prior vaginal delivery.

Methods: A retrospective cohort study was conducted including women with no prior vaginal delivery undergoing TOLAC during 2010-2020. Women with hypertensive disorder were compared to those without.

Results: A total of 54/2,144 (2.5%) TOLACs had a hypertensive disorder: 32 (59%) had gestational hypertension, 16 (30%) had chronic hypertension and 6 (11%) had preeclampsia. Women with hypertensive disorders had higher BMI and higher proportion of diabetic disorders. TOLAC success rate was lower among hypertensive mothers: 32 (59%) vs. 1,605 (76.8%), p=0.003 odds ratio (OR), 95% confidence interval (CI) 0.44 (0.25-0.76). The rate of uterine rupture was 23/2,144 (1.1%). In a multivariable logistic regression analysis, hypertensive disorder was independently negatively associated with TOLAC success, adjusted OR (95% CI) 0.47 (0.26-0.85). Other factors negatively independently associated with TOLAC failure were maternal age, predelivery body mass index, dystocia at primary CD, gestational age at TOLAC, induction of labor and birth weight. Epidural was independently positively associated with TOLAC success, adjusted OR (95% CI) 1.54 (1.18-1.99).

Conclusion: TOLAC in hypertensive women with no prior vaginal delivery is safe. Success rate is impaired in comparison to non-hypertensive women.