1. Department of Obstetrics and Gynecology (CB#7570), 101 Manning Dr, University of North Carolina at Chapel Hill, NC, USA
2. Departamento de Ginecologia e Obstetrícia, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos 2400, Porto Alegre, RS 90035-003, Brazil
3. Department of Obstetrics and Gynecology, Greenville Health System, 890 W. Faris Rd (Ste 470), Greenville, SC 29605, USA
4. Department of Pathology, University of Cambridge, Tennis Court Rd, Cambridge CB2 1QP, UK
5. Department of Pathology, Hershey Medical Center, 500 University Drive, Hershey, PA 17033, USA
6. Department of Obstetrics and Gynecology, The Whittington Hospital, National Health Service Trust, Magdala Ave, London N19 5 NF, UK