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.