[1] IMSS, UMAE Ginecol & Obstet Luis Castelazo Ayala, Res Unit Reprod Med, Mexico City 10101, DF, Mexico
[2] IMSS, UMAE Ginecol & Obstet Luis Castelazo Ayala, Dept Pathol, Mexico City 10101, DF, Mexico
[3] IMSS, UMAE Ginecol & Obstet Luis Castelazo Ayala, Dept Oncol, Mexico City 10101, DF, Mexico
[4] Univ Penn, Med Ctr, Ctr Res Reprod & Womens Hlth, Philadelphia, PA 19104 USA