[1] Univ Auckland, Sch Med, Dept Obstet & Gynecol, Auckland, New Zealand
[2] Jena Univ Hosp, Placenta Lab, Jena, Germany
[3] Univ Texas Med Branch, MRB Galveston, Dept OB GYN Cell Biol, Galveston, TX 77555 USA
[4] Brown Univ, Women & Infants Hosp, Dept Pediat, Warren Alpert Med Sch, Providence, RI 02908 USA