1. Center for Perinatal Diagnosis and Research (CEDIP), Sótero del Río Hospital, P. Universidad Católica de Chile, Puente Alto, Chile
2. Perinatology Research Branch, National Institute of Child Health and Human Development, NIH, DHHS, Bethesda, MD, Detroit, MI, USA
3. Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI, USA
4. Department of Pathology, Wayne State University School of Medicine, Detroit, MI, USA