[1] BOSTON HOSP WOMEN, TROPHOBLASTIC TUMOR SERV, LYING IN DIV, BOSTON, MA 02215 USA
[2] BOSTON HOSP WOMEN, BRIGHAM HARVARD REPRODUCT BIOL UNIT, BOSTON, MA 02215 USA
[3] HARVARD UNIV, MED SCH,NEW ENGLAND TROPHOBLASTIC DIS CTR, DEPT OBSTET & GYNECOL,398 BROOKLINE AVE, BOSTON, MA 02215 USA