1145 Predicting vaginal birth after cesarean section in black and hispanic patients

Abstract

Black and Hispanic women have higher rates of cesarean delivery(CD) compared to non-Hispanic white women. One way to decrease the number of CD is to offer vaginal birth after cesarean (VBAC). Prediction models have been used to assist providers in counseling. A widely used calculator(Grobman WA et al.Obstet Gynecol 2007) includes race/ethnicity, which lowers predicted success rates in minority women. Our objective was to examine VBAC success rates in Black and Hispanic women at an urban academic institution. This was a retrospective cohort of Black and Hispanic women with 1 prior CD admitted for delivery from 1/1/17-12/31/18. Patients were grouped according to planned delivery mode(TOLAC or scheduled CD). Exclusion criteria were EGA<24 weeks, fetal chromosome anomalies, IUFD, multiple gestation, uterine rupture at admission and contraindication for TOLAC. Self-identified race/ethnicity was reviewed from the medical record. Two VBAC predicated success rates were calculated; 1. Including race and ethnicity data; 2. Race and ethnicity documented as “no” using this calculator. 266 women met inclusion criteria. 177(66.5%) attempted TOLAC, 138(78%) women had a successful VBAC. 80(45%) were Black and 97(55%) were Hispanic. Age, parity and BMI were similar in those that declined and attempted TOLAC. The mean predicted success rate for patients attempting TOLAC was lower when race/ethnicity data was included(57 vs 73%; p <0.0001). 101(57%) of the women attempting TOLAC had a predicted rate <60%, of which 68(67.3%) had a VBAC. When calculated without race/ethnicity data, 42 were in the <60% group, of which 30(71%) had a VBAC. In women who declined TOLAC, the mean predicted success rate was higher with the second calculation (47.8 vs 62.8%; p<0.0001). Although race/ethnicity decreases predicted success rate using this calculator, our data suggests Black and Hispanic women had high rates of VBAC, even when predicted success rates were low. Removing the social constructs of race/ethnicity from calculation models may improve obstetrical outcomes in minority populations.