Comparison of vaginal breech deliveries with and without magnetic resonance imaging in primigravidas: a retrospective cohort analysis and literature review.

Purpose: Pelvimetry is often recommended in primiparous patients before offering vaginal breech delivery. Later studies show a reduction in perinatal mortality in women undergoing pelvimetry while earlier studies show the opposite. Magnetic resonance imaging (MRI), considered a new technology in 1990, has become the more expensive method for pelvimetry with lower-radiation, believed to prevent unnecessary cesarean sections and "falsely attempted vaginal deliveries".