[1] Brigham & Womens Hosp, Div Womens Hlth, Boston, MA 02115 USA
[2] McMaster Univ, Dept Clin Epidemiol & Biostat, Hamilton, ON L8L 2X2, Canada
[3] McMaster Univ, Dept Med, Hamilton, ON L8L 2X2, Canada
[4] Univ Alabama Birmingham, Dept Obstet & Gynecol, Birmingham, AL 35487 USA
[5] Mt Sinai Med Ctr, Div Endocrinol, New York, NY 10029 USA