Bladder exstrophy is a birth defect where the bladder and abdominal wall do not close properly in the womb, leaving the bladder exposed. It occurs in about 1 in 3,000 births and is more common in males. Risk factors include young maternal age and exposure to high doses of progesterone during the first trimester. Clinically, the abdominal wall is absent and the bladder lining is exposed and bright red. Surgical correction is required to repair the abdominal wall and close the bladder. Long term risks include incontinence, infection, and rarely cancer due to changes in the bladder lining.