Validation of a Vaginal Birth after Cesarean Delivery Prediction Model in Teaching Hospitals of Addis Ababa University: A Cross-Sectional Study

Abstract

Background. External validation of a vaginal birth after cesarean delivery (VBAC) prediction model is important before implementation in other settings. The primary aim of this study is to validate the Grobman prenatal VBAC calculator in the Ethiopian setting. Secondarily, the study was aimed at developing and comparing a new VBAC model that includes both the prenatal and intrapartum variables. Methods. A cross-sectional survey was conducted, complemented by a medical chart review of 268 women admitted at three teaching hospitals of Addis Ababa University and who underwent a trial of labor after one prior cesarean birth. Maternal age, prepregnancy BMI, prior vaginal delivery, prior VBAC, and prior cesarean delivery indication type were included in the Grobman model. Observed delivery outcomes were recorded and then compared with the outcomes predicted by the calculator. We assessed the predictive abilities of the Grobman model and the new model using a receiver operating characteristic (ROC) curve. Multivariate logistic regression analysis was conducted to identify variables associated with successful VBAC. Results. Out of the 268 participants, 186 (69.4%) (95% CI 57.5-81.3) had successful VBAC. The area under the ROC curve (AUC) of the Grobman model was 0.75 (95% CI 0.69-0.81). Notably, the novel model including both the prenatal and intrapartum variables had a better predictive value than the original model, with an AUC of 0.87 (95% CI 0.81-0.93). Prior VBAC, prepregnancy BMI, fetal membrane status, and fetal station at admission were predictors of VBAC in the newly developed logistic regression model. Conclusions. The success rate of VBAC was similar to other sub-Saharan African countries. The Grobman model performed adequately in the study setting; however, the model including both the prenatal and intrapartum variables was more predictive. Thus, intrapartum predictors used in the new model should be considered during intrapartum counseling.

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

“…15 More recent studies in sub-Saharan African countries have reported similar results, with studies reporting a VBAC success rate of 61% in Ghana, 67% in Nigeria, and 50-69% in Ethiopia. [16][17][18][19] The range of VBAC success rates may be a result of different methodologies used in these studies.…”

“…[30][31][32][33] In 2020, the Grobman prenatal VBAC calculator was validated in Ethiopia. 18 This Grobman model uses information that is able to be assessed at patients' first prenatal consultation. 30 Importantly, in this study, the variables that were found to be significantly associated with a woman having a successful VBAC could not have been assessed at their first consultation.…”

“…Previous studies have found that maternal obesity is associated with a lower VBAC success rate. 18,35,36 Future research should examine how BMI and a prior VBAC in patients from the DRC influence the rate of VBAC success and adjust VBAC recommendations appropriately. In addition, future research efforts should incorporate multiple hospitals to obtain a greater, more representative sample.…”

Determinants of successful trial of labor after a previous cesarean delivery in East Wollega, Western Ethiopia: A case–control study

“… 7 A study in Addis Ababa showed 69.4% of mothers had successful VBAC. 8 Therefore, identifying determinants of VBAC delivery, especially in a resource-limited setting, reduces cesarean delivery rates, and thus decreases maternal morbidities from cesarean deliveries. It also saves financial resources in the health sector.…”

Determinants of Successful Vaginal Birth After Caesarean Section at Public Hospitals in Ambo Town, Oromia Region, Central Ethiopia: A Case-Control Study

“…12 , 14 , 15 A study in Addis Ababa showed that 69.4% of mothers had a successful VBAC. 16 Moreover, VBAC is a safe and appropriate choice for most mothers with a prior CS. However, the number of mothers who experienced trial of labor after caesarean section (TOLAC) is decreasing, resulting in an overall rise in CS rate.…”