[1] Harvard Univ, Sch Med, Brigham & Womens Hosp,MD Trophoblast Tumor Regist, Dana Farber Canc Inst,New England Trophoblast Dis, Boston, MA 02115 USA
[2] Yale Univ, Sch Med, Dept Gynecol, New Haven, CT USA
[3] Univ London Imperial Coll Sci Technol & Med, Div Surg Oncol Reprod Biol & Anaesthet, London, England