Risk factors of unsuccessful vaginal twin delivery

Abstract

Introduction: Twin trial of labor presents a challenge to obstetricians, as it is associated with a greater number of adverse birth outcomes compared with singleton deliveries. The risk of poor outcome has shown to be highest with unsuccessful vaginal twin delivery. The purpose of this study was to identify the clinical risk factors associated with intrapartum cesarean section in late preterm and term twin births. Material and methods: All live diamniotic twin deliveries of at least 35 +0 weeks of gestation with planned vaginal delivery were included in this retrospective singlecenter cohort study. Maternal and newborn characteristics were compared between a vaginal delivery group and an intrapartum cesarean section group. Logistic regression analysis was carried out to determine independent risk factors of intrapartum cesarean section. Further, maternal and neonatal outcomes were compared between groups of vaginal delivery and cesarean section for both twins and also between groups of vaginal delivery and cesarean section for the second twin only (combined delivery). The impact of presentation of the second twin on the mode of twin delivery and on neonatal outcome was also examined. Results: Among 821 twin pregnancies, 581 mothers (70.8%) attempted trial of labor and were eligible for the study. With a cephalic-presenting first twin, the trial of labor rate was 89.3% and vaginal delivery was successful in 82.8%. Nulliparity (odds ratio [OR] 3.2, 95% confidence interval [CI] 2.0-5.1) and non-cephalic presentation of the second twin (OR 3.0, 95% CI 1.9-4.8) were found to be independent risk factors of cesarean section. However, 76.1% of mothers with non-cephalic second twins achieved vaginal delivery and perinatal outcomes were comparable with cases of cephalic-presenting second twins. When comparing delivery modes, maternal outcomes were more favorable with vaginal delivery, whereas combined delivery increased the second twin's risk of adverse neonatal outcome. Conclusions: This study, with high rates of trial of labor and successful vaginal twin delivery, found nulliparity and non-cephalic presentation of the second twin to be risk factors of intrapartum cesarean section in twin pregnancies.

Mode of delivery of Finnish dichorionic and monochorionic‐diamniotic twins: A retrospective observational study including a risk score for intrapartum cesarean birth

“…Advanced maternal age has been associated with CD, particularly due to failed induction or labor arrest, but not in all studies. 13 , 14 , 15 , 16 We found higher maternal age related to intrapartum CD even though we used a lower‐than‐customary cut‐off age of 32 years. Despite this finding, ART (including any form) remained a significant risk factor for intrapartum CD in adjusted analyses.…”

“…Previously, conflicting reports existed. 15 , 16 , 21 , 22 Since the presentation of the second twin may change during delivery in up to 12%, TOL should be considered also when twin B is noncephalic. 22 , 23 Data on VD of twin A presenting breech are scarce, yet a success rate of 60% has been reported with corresponding neonatal outcomes.…”

“…Overall, 70.7% of induced deliveries were vaginal, slightly lower than previously reported. 16 , 19 Induction of labor likely cancelled the effects of potential fetal distress and term birth in regression analysis and thus the role of these factors could not be reliably analyzed. This treatment paradox is a possible limitation of the study.…”

“…12 , 13 , 14 Nulliparity and noncephalic second twin have been identified as potential risk factors for intrapartum CD, but the role of maternal age or ART is less clear. 15 , 16 Although spontaneous prematurity is common, induction of labor is also often needed before term and depending on chorionicity. 2 , 4 , 17 , 18 Overall, the magnitude of the risk of intrapartum CD after induction of labor among twins is debated.…”

“… 22 , 23 Even though unstable, lie and nonvertex presentation (nonbreech in particular) of the second twin has been suggested as risk factors for CD; TOL seems to be a safe and often successful option. 5 , 11 , 15 , 16 , 21 , 22 , 23 , 24 As vaginal delivery (VD) is generally aimed at in uncomplicated diamniotic twin pregnancies with the first twin in cephalic presentation, more data is needed to define parturients at the highest risk of intrapartum CD. 25 , 26 , 27 , 28 With breech‐presenting first twin, planned CD is often recommended, but in well‐selected patients, TOL may also be considered.…”