Vaginal birth after caesarean section: a cohort study investigating factors associated with its uptake and success.

OBJECTIVES: To investigate the demographic and obstetric factors associated with the uptake and success rate of vaginal birth after caesarean section (VBAC). DESIGN: Cohort study using data from Hospital Episode Statistics. SETTING: English National Health Service. POPULATION: Women whose first birth resulted in a live singleton delivery by caesarean section between 1 April 2004 and 31 March 2011, and who had a second birth before 31 March 2012. METHODS: Logistic regression to estimate adjusted odds ratios (OR). MAIN OUTCOME MEASURES: Attempted and successful VBAC. RESULTS: Among the 143,970 women in the cohort, 75,086 (52.2%) attempted a VBAC for their second birth. Younger women, those of non-white ethnicity and those living in a more deprived area had higher rates of attempted VBAC. Overall, 47,602 women (63.4%) who attempted a VBAC had a successful vaginal birth. Younger women and women of white ethnicity had higher success rates. Black women had a particularly low success rate (OR, 0.54; 95% confidence interval [CI], 0.50-0.57). Women who had an emergency caesarean section in their first birth also had a lower VBAC success rate, particularly those with a history of failed induction of labour (OR, 0.59; 95% CI, 0.53-0.67). CONCLUSION: In this national cohort, just over one-half of women with a primary caesarean section who were eligible for a trial of labour attempted a VBAC for their second birth. Of these, almost two-thirds successfully achieved a vaginal delivery.