According to this study in
"Obstetrics & Gynecology 2008;111:285-291
C 2008 by The American College of Obstetricians and Gynecologists"
Secondary VBAC's are considered
"CONCLUSION: Women with prior successful VBAC attempts are at low risk for
maternal and neonatal complications during subsequent VBAC attempts. An
increasing number of prior VBACs is associated with a greater probability of
VBAC success, as well as a lower risk of uterine rupture and perinatal
complications in the current pregnancy. "
Dr. Brian M. Mercer, of Case Western Reserve University in Cleveland, Ohio,
and colleagues studied the impact of prior vaginal birth after cesarean on
outcomes of attempted vaginal births in subsequent pregnancies in 13,532
Even ACOG considers Secondary VBAC as low risk.