from Midwifery Today...wow...yet another reason to try to avoid a cesarean:
A study to determine whether breech presentation at term is more common among women with at least one prior cesarean delivery showed a rate two times that for women who had had vaginal births. The study records of 84,688 women showed the relative risk of a breech presentation at term for women with a history of cesarean was 2.18, with no difference related to the number of cesareans. While a total of 2.46% of all women in the study had breech babies at term, 14.91% of those who had had a cesarean had a breech. The researchers took into account other factors, including gestational age, maternal age, parity, birth weight and oligohydramnios.
— Am J Obstet Gynecol, 13 Feb 2008 (10.1016/j.ajog.2007.11.009)