Which of the following statements concerning placenta previa is true?

The initial hemorrhage in placenta previa is usually painless and rarely fatal. If the fetus is premature and if hemorrhaging is not severe, vaginal examination of a woman suspected of having placenta previa frequently can be delayed until 37 weeks gestation; this delay in the potentially hazardous examination reduces the risk of prematurity, which is often associated with placenta previa. Vaginal examination, when needed to determine whether a low- lying placenta is covering the internal os of the cervix, should be performed in an operating room fully prepared for an emergency cesarean section (i.e., a double setup). Increasing maternal age and multiparity are associated with a higher incidence of placenta previa.