1. Sección de Estudios de Posgrado, Escuela Superior de Medicina, Instituto Politécnico Nacional, Mexico City 11340, Mexico
2. Reproductive and Perinatal Health Research Department, National Institute of Perinatology, Ministry of Health, Mexico City 11000, Mexico
3. Coordination of Gynecological and Perinatal Endocrinology, National Institute of Perinatology, Ministry of Health, Mexico City 11000, Mexico
4. Peri and Postmenopause Clinic, National Institute of Perinatology, Ministry of Health, Mexico City 11000, Mexico
5. School of Medicine, University of California San Diego, San Diego, CA 92093, USA