1. Department de Obstetricia y Ginecología, Unidad de Medicina Materno Fetal, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santaigo, Chile; Department of Obstetrics and Gynecology, University of Kansas School of Medicine, Kansas City, Kansas; Marcoleta 391, Centro de Investigaciones Médicas, Pontificia Universidad Católica de Chile, Santiago, Chile
2. Department de Obstetricia y Ginecología, Unidad de Medicina Materno Fetal, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santaigo, Chile; Department of Obstetrics and Gynecology, University of Kansas School of Medicine, Kansas City, Kansas