[1] Johns Hopkins Univ, Dept Gynecol, Baltimore, MD 21287 USA
[2] Johns Hopkins Univ, Dept Obstet, Baltimore, MD 21287 USA
[3] Univ Rochester, Rochester, NY USA
[4] Brown Univ, Warren Alpert Med Sch, Providence, RI 02912 USA
[5] Univ Naples Federico II, Sch Med, Dept Neurosci Reprod Sci & Dent, Naples, Italy
[6] Thomas Jefferson Univ, Dept Obstet & Gynecol, Div Maternal Fetal Med, Sidney Kimmel Med Coll, Philadelphia, PA 19107 USA