Previous preterm cesarean delivery and risk of uterine rupture in subsequent trial of labor-a national cohort study.

BACKGROUND: Previous cesarean delivery is the major risk factor for uterine rupture in subsequent trial of labor. It has been suggested that a previous preterm cesarean delivery is associated with an increased risk of uterine rupture compared with a previous term cesarean delivery. However, the proposed association has only been investigated in a few studies and never in a study based on unselected contemporary prospectively collected data. OBJECTIVE: This study aimed to investigate the risk of uterine rupture among women attempting trial of labor after 1 previous preterm cesarean delivery compared with women with 1 previous term cesarean delivery. STUDY DESIGN: In this population-based cohort study, we used the Swedish Medical Birth Register between 1983 and 2016 and identified 9300 women with 1 previous preterm index cesarean delivery, 57,168 women with 1 previous term index cesarean delivery, and a second outcome delivery defined as trial of labor after 1 previous cesarean delivery. The risk of the main outcome uterine rupture and secondary outcomes placental abruption; placenta accreta spectrum; postpartum hemorrhage; blood transfusion; appearance, pulse, grimace, activity, and respiration of <7 at 5 minutes; neonatal cerebral dysfunction; and neonatal seizures were assessed using multivariate logistic regression models adjusted for potential confounders. RESULTS: Among women with a preterm index cesarean delivery, 102 (1.1%) had uterine rupture in the outcome delivery compared with 759 of women (1.4%) with term index cesarean delivery. This corresponded to a decreased risk of uterine rupture for women with preterm index cesarean delivery (odds ratio, 0.79; 95% confidence interval, 0.64-0.97), which did not remain significant in the analysis adjusted for maternal age, interdelivery interval, maternal body mass index, maternal height, induction of labor, postoperative infection after index cesarean delivery, and birthweight (odds ratio, 0.94; 95% confidence interval, 0.74-1.18). Stratifying by gestational week at index cesarean delivery (32+0 to 36+6 and <32+0 weeks' gestation) did not alter the main result. Stratifying by interdelivery interval revealed that women with a preterm index cesarean delivery were at a decreased risk of uterine rupture (odds ratio, 0.55 [95% confidence interval, 0.39-0.78]; adjusted odds ratio, 0.74 [95% confidence interval, 0.51-1.07]) in interdelivery intervals of >36 months whereas there were no significant differences within other time intervals. Of the secondary outcomes, 89 women (1.0%) with preterm index cesarean delivery were diagnosed as having placental abruption compared with 331 women (0.6%) with term index cesarean delivery, which corresponded to an approximately 60% increased risk (odds ratio, 1.66; 95% confidence interval, 1.31-2.10), which remained significant after adjusting for confounders (odds ratio, 1.49; 95% confidence interval, 1.13-1.96). Likewise, there was a slightly increased risk of postpartum hemorrhage for women with preterm index cesarean delivery (adjusted odds ratio, 1.12; 95% confidence interval, 1.02-1.24). There were no significant differences in the remaining secondary outcomes. CONCLUSION: The findings of this study suggest that preterm cesarean delivery is not associated with an increased risk of uterine rupture. Hence, women with 1 previous preterm cesarean delivery (with lower uterine segment incision) should receive medical management and counseling similar to women with previous term cesarean delivery before trial of labor after cesarean delivery.

Predicting vaginal birth after previous cesarean: Using machine-learning models and a population-based cohort in Sweden.

INTRODUCTION: Predicting a woman's probability of vaginal birth after cesarean could facilitate the antenatal decision-making process. Having a previous vaginal birth strongly predicts vaginal birth after cesarean. Delivery outcome in women with only a cesarean delivery is more unpredictable. Therefore, to better predict vaginal birth in women with only one prior cesarean delivery and no vaginal deliveries would greatly benefit clinical practice and fill a key evidence gap in research. Our aim was to predict vaginal birth in women with one prior cesarean and no vaginal deliveries using machine-learning methods, and compare with a US prediction model and its further developed model for a Swedish setting. MATERIAL AND METHODS: A population-based cohort study with a cohort of 3116 women with only one prior birth, a cesarean, and a subsequent trial of labor during 2008-2014 in the Stockholm-Gotland region, Sweden. Three machine-learning methods (conditional inference tree, conditional random forest and lasso binary regression) were used to predict vaginal birth after cesarean among women with one previous birth. Performance of the new models was compared with two existing models developed by Grobman et al (USA) and Fagerberg et al (Sweden). Our main outcome measures were area under the receiver-operating curve (AUROC), overall accuracy, sensitivity and specificity of prediction of vaginal birth after previous cesarean delivery. RESULTS: The AUROC ranged from 0.61 to 0.69 for all models, sensitivity was above 91% and specificity below 22%. The majority of women with an unplanned repeat cesarean had a predicted probability of vaginal birth after cesarean >60%. CONCLUSIONS: Both classical regression models and machine-learning models had a high sensitivity in predicting vaginal birth after cesarean in women without a previous vaginal delivery. The majority of women with an unplanned repeat cesarean delivery were predicted to succeed with a vaginal birth (ie specificity was low). Additional covariates combined with machine-learning techniques did not outperform classical regression models in this study.

Risk of repeat cesarean delivery in women undergoing trial of labor: A population-based cohort study.

INTRODUCTION: The aim of this study was to consult women on best mode of delivery after a first cesarean section, more knowledge regarding risk for a repeat unplanned cesarean is needed. We investigated the association between indication of first cesarean and cervical dilation during labor preceding the first cesarean and risk of repeat cesarean in women undergoing trial of labor. MATERIAL AND METHODS: A population-based cohort study using electronic medical records of all women delivering in the Stockholm-Gotland region, Sweden, between 2008 and 2014. The population consisted of 3116 women with a first cesarean undergoing a trial of labor with a singleton infant in cephalic presentation at ≥37 weeks of gestation. Relative risks (RR) with 95% CI were estimated using Poisson regression analyses. RESULTS: Women with a first unplanned cesarean had higher risk of repeat cesarean compared with women with elective first cesarean (35.7% vs 20.7%, adjusted RR 1.64, 95% CI 1.43-1.89). In women with a cesarean due to dystocia, increasing cervical dilation in first labor decreased the risk of repeat cesarean in second labor. The adjusted RR of repeat cesarean was 2.48 with dilation ≤5 cm, 1.98 with dilation 6-10 cm, and 1.46 if fully dilated. CONCLUSIONS: Almost 70% of all women eligible for trial of labor after cesarean had a vaginal birth, even women with a history of labor dystocia had a good chance of success. A greater cervical dilation in the first delivery ending with a cesarean was not in vain, since the chance of vaginal birth in the subsequent delivery increased with greater dilation.

Risk of negative birth experience in trial of labor after cesarean delivery: A population-based cohort study.

BACKGROUND: To improve care for women going through trial of labor after cesarean (TOLAC), we need to understand their birth experience better. We investigated the association between mode of delivery on birth experience in second birth among women with a first cesarean. METHODS: A population-based cohort study based on the Swedish Pregnancy Register with 808 women with a first cesarean and eligible for TOLAC in 2014-2017. Outcomes were mean birth experience measured by visual analogue scale (VAS) score from 1-10 and having a negative birth experience defined as VAS score ≤5. Linear and logistic regression analyses were performed with ß-estimates and odds ratios (OR) with 95% confidence intervals (CI). RESULTS: Mean VAS score among women with an elective repeat cesarean (n = 251 (31%)), vaginal birth (n = 388 (48%)) or unplanned repeat cesarean (n = 169 (21%)) in second birth were 8.8 (standard deviation SD 1.4), 8.0 (SD 2.0) and 7.6 (SD 2.1), respectively. Compared to women having an elective repeat cesarean, women having an unplanned repeat cesarean delivery had five-fold higher odds of negative birth experience (adjusted OR 5.0, 95% CI 1.5-16.5). Women having a first elective cesarean and a subsequent unplanned repeat cesarean delivery had the highest odds of negative birth experience (crude OR 7.3, 95% CI 1.5-35.5). CONCLUSIONS: Most women with a first cesarean scored their second birth experience as positive irrespective of mode of delivery. However, the odds of a negative birth experience increased among women having an unplanned repeat cesarean delivery, especially when the first cesarean delivery was elective.