[1] Thomas Jefferson Univ Hosp, Div Maternal Fetal Med, Dept Obstet & Gynecol, 833 Chestnut St,1st Floor, Philadelphia, PA 19107 USA
[2] Thomas Jefferson Univ Hosp, Dept Obstet & Gynecol, Philadelphia, PA 19107 USA
[3] Univ Naples Federico II, Sch Med, Dept Neurosci Reprod Sci & Dent, Naples, Italy
[4] Univ Oklahoma, Coll Med, Dept Obstet & Gynecol, Oklahoma City, OK 73190 USA
[5] Univ Rochester, Med Ctr, Div Maternal Fetal Med, Dept Obstet & Gynecol, Rochester, NY 14642 USA
[6] Univ Texas Med Branch, Dept Obstet & Gynecol, Div Maternal Fetal Med, Galveston, TX 77555 USA
[7] Washington Univ, Sch Med, Div Maternal Fetal Med, St Louis, MO USA
[8] Univ N Carolina, Div Maternal Fetal Med, Dept Obstet & Gynecol, Chapel Hill, NC 27515 USA