Vaginal birth after Caesarean (VBAC) can have risks, including uterine rupture. Because of this malpractice risk, some OBs refuse to do them:

But she says she was shocked when at eight months pregnant, her doctor’s office, Simmonds and Simmonds in Frederick, gave her a letter telling her they were letting her go. They said it was because she challenged the use of a fetal heart monitor during labor and insisted on having a VBAC, a somewhat controversial procedure that some doctors say carries a higher risk of uterine rupture . . .

. . . “If the patient comes to the physician with unreasonable demands, and will not allow him to deliver them in a safe manner, then the physician has the right to discharge the patient from his practice,” says Dr. Chet Wyman, vice president of medical affairs at FMH.

Update:
#1 Dinosaur says the situation sucks.