[1] Univ Utah Hlth, Salt Lake City, UT USA
[2] Univ Arkansas Med Sci, Dept Obstet & Gynecol, Div Maternal Fetal Med, Little Rock, AZ USA
[3] Univ Calif Los Angeles, David Geffen Sch Med, Dept Obstet & Gynecol, Div Maternal Fetal Med, Los Angeles, CA USA
[4] Univ Arkansas Med Sci, Dept Anesthesiol, Little Rock, AZ USA
[5] Texas Childrens Hosp Pavil Women, Baylor Coll Med, Dept Obstet & Gynecol, Div Maternal Fetal Med, Houston, TX USA
[6] Vanderbilt Univ, Dept Obstet & Gynecol, Div Maternal Fetal Med, Med Ctr, Nashville, TN USA
[7] Harvard Med Sch, Beth Israel Deaconess Med Ctr, Boston, MA USA
[8] Texas Childrens Hosp, Baylor Coll Med, Dept Radiol, Houston, TX USA
[9] Harvard Med Sch, Brigham & Womens Hosp, Boston, MA USA
[10] Yale Sch Med, New Haven, CT USA
[11] 30 N 1900 East,Suite 2B200, Salt Lake City, UT 84132 USA