Factors Associated with Successful Vaginal Birth After a Primary Cesarean Section in Women with an Optimal Inter-Delivery Interval

Abstract

Purpose: We sought to determine the success rate of VBAC and factors associated with achieving VBAC at a referral hospital in the Democratic Republic of Congo in women with a subsequent pregnancy greater than or equal to 18 months from their primary cesarean section (CS). Patients and Methods: Patients were included for participation if they had an interdelivery interval (IDI) of at least 18 months from their primary CS, accepted TOLAC, and had no contraindications. Information was collected about patients' demographics, obstetric history, and factors impacting their labor process. Descriptive analyses compared patients that had a successful VBAC and those who did not. Univariate and multivariate binary logistic regression models identified factors associated with a successful VBAC. Results: Among 231 eligible patients who attempted a VBAC, 57.6% (133) achieved VBAC. Participants had a mean age of 29 (SD 6), with the majority having a prior vaginal delivery (68.8%). VBAC was positively associated with a higher Bishop score (AOR 1.12, 95% CI 1.02, 1.23) and a spontaneous labor onset (AOR 3.06, 95% CI 1.52, 6.17). VBAC was negatively associated with a macrosomic fetus (AOR 0.21, 95% CI 0.08, 0.58). Conclusion: TOLAC results in VBAC more than half the time and is associated with a spontaneous labor onset and a higher Bishop score. Women with a macrosomic fetus were more likely to have an unsuccessful VBAC, resulting in an RCS. An optimal IDI was not enough to ensure a successful VBAC. Upon patients' arrival to the hospital, practitioners should re-evaluate their eligibility to attempt a VBAC based on their Bishop score and if they had a spontaneous labor onset to decrease the health risks of an RCS.

Factores predictores del éxito del parto vaginal posterior a cesárea

“…El PVPC es deseable; además, los resultados de este estudio y otras investigaciones previas han mostrado resultados exitosos y seguros (3,6,(9)(10)(11)(12) . El propósito de nuestro estudio fue identificar los factores que aumentan la tasa de éxito y reducen la morbimortalidad materna y perinatal, las cuales podrían complicar la resultante de la prueba de trabajo de parto en pacientes con cesárea previa.…”

“…La tasa de PVPC en esta investigación fue de 67,4%, lo que la ubica dentro del rango sugerido entre 60% y 80%, y es ligeramente mayor que lo encontrado en investigaciones previas (6,(8)(9)(10)(11)(12) . Las diferencias observadas en informes previos pueden reflejar los efectos de varios factores.…”

“…Diferentes estudios han mostrado que el parto vaginal en pacientes con antecedentes de cesárea es seguro (8)(9)(10) . Otros informes han proporcionado evidencia que 60% a 80% de las pruebas de parto posterior a cesárea culminan en partos vaginales exitosos (11,12) .…”

Effect of Short Inter-Pregnancy Interval on the Outcome of Vaginal Birth after Cesarean Section

“…17 However, no significant difference was observed in the spontaneous onset of labour and the need for induction and augmentation of labour for an inter-pregnancy interval in our study. A few systemic reviews and meta-analysis, [18][19][20] done internationally and locally were available on the predictors of a successful VBAC; however, no local studies were available to determine the influence of shorter interpregnancy interval on successful vaginal birth prior to cesarean section; thus, we conducted this study on the local population. Our study concluded that with increasing inter-pregnancy interval the chances of a successful VBAC increase (p=0.001) with fewer reported complications.…”

Predicción de parto vaginal aplicando los puntajes Grobman y Flamm en el Hospital Nacional Docente Madre Niño San Bartolomé 2021

“…En el 2007, Grobman creo un nomograma de predicción, cimentado en factores de la primera atención prenatal, como "edad de la madre, IMC, etnia, parto vaginal previo, parto vaginal exitoso tras cesárea y recurrencia de indicación de cesárea primaria". Posteriormente, en el 2009 se incluyeron factores para ingreso a sala de parto, como el índice de masa corporal al parto, preeclampsia y edad gestacional al nacimiento (19,20). La suma total de estos factores oscilará entre 0 y 90, que representan el 1 y 99% de probabilidades de parto vaginal exitoso, con un punto de corte de 50 y 60% (21).…”