[1] Mayo Clin, Dept Obstet & Gynecol, 200 First St SW, Rochester, MN 55905 USA
[2] Cleveland Clin, Sect Abdominal Imaging, Imaging Inst, 9500 Euclid Ave A-21, Cleveland, OH 44106 USA
[3] NYU, Dept Obstet & Gynecol, 550 First Ave, New York, NY 10016 USA